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赶塑坠 发表于 2025-9-28 18:27:43

WPF+MVVM入门学习

最近在学WPF的MVVM，有两种方式实现，一种是自己实现，一种是借助MVVM框架，接下来通过一个医院自助打印报告机键盘输入界面来演示自己实现、框架CommunityToolkit和Prism的区别。
项目源码：https://gitee.com/cplmlm/SelfServiceReportPrinter
https://github.com/cplmlm/SelfServiceReportPrinter
推荐学习博主：B站UP十月的寒流
一、自己实现

1、首先我们创建一个BaseNotifyPropertyChanged类，继承INotifyPropertyChanged，这个方法的作用是属性值变化时自动更新UI界面。
public class BaseNotifyPropertyChanged : INotifyPropertyChanged
{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public event PropertyChangedEventHandler? PropertyChanged;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public void RaisePropertyChanged(string propertyName)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> if (!string.IsNullOrEmpty(propertyName))
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
}2、创建一个KeyPressViewModel类，继承BaseNotifyPropertyChanged。
public class KeyPressViewModel : BaseNotifyPropertyChanged
{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private string cardNumber;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private int selectionStart=0;

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 输入文本框的值
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public string CardNumber
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> get { return cardNumber; }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> set
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> cardNumber = value;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> RaisePropertyChanged(nameof(CardNumber));
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 输入框光标位置
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public int SelectionStart
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> get { return selectionStart; }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> set { RaisePropertyChanged(nameof(SelectionStart)); }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 数字按钮绑定事件
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public ICommand NumberCommand
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> get { return new RelayCommand<string>(Number); }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 清空按钮绑定事件
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public ICommand ClearCommand
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> get { return new RelayCommand(Clear); }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 删除按钮绑定事件<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public ICommand DeleteCommand
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> get { return new RelayCommand(Delete); }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 数字点击事件
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <param name="key"></param>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private void Number(string? key)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> CardNumber += key;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 清空点击事件
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private void Clear()
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> CardNumber = string.Empty;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// <summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 删除点击事件
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// </summary>
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private void Delete()
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> // 光标在输入框时，删除光标前一个字符
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> if (!string.IsNullOrEmpty(CardNumber) && SelectionStart > 0)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> CardNumber = CardNumber.Remove(SelectionStart - 1, 1);
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> //光标没有在输入框时，删除最后一个字符
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> if (SelectionStart == 0)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> CardNumber = CardNumber.Remove(CardNumber.Length - 1, 1);
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> }
}3、创建RelayCommand类，这个类的作用是绑定事件的操作，一个泛型版本，一个是非泛型。
public class RelayCommand : ICommand
{

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private Action _execute;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private Func<bool> _canExecute;


<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public RelayCommand(Action execute) : this(execute, null)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public RelayCommand(Action execute, Func<bool> canExecute)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (execute == null)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />throw new ArgumentNullException("execute");
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />_execute = execute;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />_canExecute = canExecute;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public event EventHandler? CanExecuteChanged
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />add
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (_canExecute != null)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CommandManager.RequerySuggested += value;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />remove
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (_canExecute != null)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CommandManager.RequerySuggested -= value;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public bool CanExecute(object parameter)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />return _canExecute == null ? true : _canExecute();
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public void Execute(object parameter)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />_execute();
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}
}public class RelayCommand<T> : ICommand
{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private readonly Predicate<T> _canExecute;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private readonly Action<T> _execute;

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public RelayCommand(Action<T> execute) : this(execute, null)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public RelayCommand(Action<T> execute, Predicate<T> canExecute)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (execute == null)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />throw new ArgumentNullException("execute");
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />_execute = execute;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />_canExecute = canExecute;
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public event EventHandler? CanExecuteChanged
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />add { CommandManager.RequerySuggested += value; }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />remove { CommandManager.RequerySuggested -= value; }
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public bool CanExecute(object parameter)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />return _canExecute == null ? true : _canExecute((T)parameter);
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}

<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public void Execute(object parameter)
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />_execute((T)parameter);
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}
}4、通过binding绑定输入框的值和事件的操作，代替传统直接在后台cs文件写事件。
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />5、将MainWindow的DataContext赋值给ViewModel，我这里用了依赖注入的方法，所以直接是在app.cs里面赋值的，也可以在MainWindow.cs。
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public partial class App : Application<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public App()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />Services = ConfigureServices();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />this.InitializeComponent();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// Gets the current<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />instance in use<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public new static App Current => (App)Application.Current;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// Gets the<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />instance to resolve application services.<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public IServiceProvider Services { get; }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// Configures the services for the application.<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private static IServiceProvider ConfigureServices()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />var services = new ServiceCollection();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />services.AddTransient();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />services.AddTransient();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />services.AddTransient();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />services.AddTransient(sp=>new MainWindow() { DataContext=sp.GetRequiredService()});<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />return services.BuildServiceProvider();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />protected override void OnStartup(StartupEventArgs e)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />base.OnStartup(e);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />MainWindow= Services.GetRequiredService();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />MainWindow.Show();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public partial class MainWindow : Window<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public MainWindow()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />InitializeComponent();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />DataContext =App.Current.Services.GetService();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}6、如果不用依赖注入的方式，可以在MainWindow.xaml或者MainWindow.cs将MainWindow的DataContext赋值给ViewModel。
<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public partial class MainWindow : Window {<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> public MainWindow()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> {<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> InitializeComponent();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> DataContext =new KeyPressViewModel();<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> } }以上就是自己去实现mvvm的方式，会比较繁琐，如果不是复杂的项目大多数还是用社区的CommunityToolkit.MVVM，复杂的项目可以使用Prism
二、使用微软社区的CommunityToolkit.MVVM

1、首先安装CommunityToolkit.MVVM的包。

2、创建一个新的类KeyPressViewModelCommunityToolkit类，继承ObservableObject，CommunityToolkit代码就简洁很多了，直接在方法或者属性上面加特性就可以。
public partial class KeyPressViewModelCommunityToolkit : ObservableObject{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private string cardNumber = string.Empty;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private int selectionStart;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 数字点击事件<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> ///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> <TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private void Number(string? key)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber += key;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 清空输入框<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> <TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private void Clear()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber = string.Empty;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 删除点击事件<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> <TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private void Delete()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />// 光标在输入框时，删除光标前一个字符<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (!string.IsNullOrEmpty(CardNumber) && SelectionStart > 0)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber = CardNumber.Remove(SelectionStart - 1, 1);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />//光标没有在输入框时，删除最后一个字符<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (SelectionStart == 0)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber = CardNumber.Remove(CardNumber.Length - 1, 1);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}}三、Prism

1、安装Prism.Core和Prism.Wpf,其他的包根据后续实际使用在安装。

2、创建一个KeyPressViewModelPrism类继承BindableBase。
public partial class KeyPressViewModelPrism : BindableBase{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private string cardNumber;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />private int selectionStart;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public string CardNumber<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />get { return cardNumber; }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />set { SetProperty(ref cardNumber, value); }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public int SelectionStart<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />get { return selectionStart; }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />set { SetProperty(ref selectionStart, value); }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public DelegateCommand NumberCommand { get; }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public DelegateCommand ClearCommand { get; }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public DelegateCommand DeleteCommand { get; }<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />public KeyPressViewModelPrism()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />NumberCommand = new DelegateCommand(Number);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />ClearCommand = new DelegateCommand(Clear);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />DeleteCommand = new DelegateCommand(Delete);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 数字点击事件<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> ///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private void Number(string? key)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber += key;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 清空点击事件<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private void Clear()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber = string.Empty;<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> /// 删除点击事件<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />///<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /> private void Delete()<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />// 光标在输入框时，删除光标前一个字符<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (!string.IsNullOrEmpty(CardNumber) && SelectionStart > 0)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber = CardNumber.Remove(SelectionStart - 1, 1);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />//光标没有在输入框时，删除最后一个字符<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />if (SelectionStart == 0)<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />{<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />CardNumber = CardNumber.Remove(CardNumber.Length - 1, 1);<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}<TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   /><TextBox Text="{Binding CardNumber}"   x:Name="CardNumberTextBox"   local:TextBoxSelectionHelper.SelectionStart="{Binding SelectionStart, Mode=TwoWay}" Height="40"   Width="460" />
<ButtonContent="1"Command="{Binding NumberCommand}"CommandParameter="1"/>
<ButtonContent="删除"Command="{Binding DeleteCommand}"   />
<ButtonContent="清空"Command="{Binding ClearCommand}"   />}}四、总结

以上就是三种不同ViewModel的实现方式，个人比较推荐使用社区的CommunityToolkit，但是还是要根据自己的项目情况来决定。

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