MVVM：使用DataGrid CheckBox IsChecked屬性來控制鄰居文本框的TextDecorations

Question

我需要在不中斷MVVM（無代碼隱藏/事件）的情況下完成以下操作。我有一個CheckBox列和TextBox列的DataGrid。如果複選框被選中，我想將TextBox的TextDecorations屬性更改爲刪除線。雖然編譯器不討厭我的XAML，但它不起作用。我對DataGridTextBoxColumn XAML如下：

<DataGridTextColumn Header="Item Description" Binding="{Binding Path=ItemDescription, Mode=TwoWay}" Width="175"> 
         <DataGridTextColumn.ElementStyle> 
          <Style TargetType="TextBlock"> 
           <Setter Property="TextWrapping" Value="Wrap"/> 
           <Setter Property="TextAlignment" Value="Center" /> 
           <Style.Triggers> 
            <DataTrigger Binding="{Binding ElementName=complete, Path=IsChecked}" Value="True"> 
             <Setter Property="TextDecorations" Value="Strikethrough"/> 
            </DataTrigger> 
           </Style.Triggers> 
          </Style>  
         </DataGridTextColumn.ElementStyle> 
        </DataGridTextColumn> 

Answer 1

因爲在的ItemsSource DataGrid中每個元素的運行時創建它自己的TextBlock和CheckBox你不能有綁定到該元素的名稱。相反，您應該將複選框的值和TextBlock的樣式設置器綁定到您的模型。例如，你有模型和視圖模型是這樣的：

型號：

public class SomeModel : INotifyPropertyChanged 
{ 
    private string textField; 
    private bool boolField; 
    public event PropertyChangedEventHandler PropertyChanged; 

    public string TextField 
    { 
     get { return textField; } 
     set 
     { 
      if (value == textField) return; 
      textField = value; 
      OnPropertyChanged(); 
     } 
    } 

    public bool BoolField 
    { 
     get { return boolField; } 
     set 
     { 
      if (value.Equals(boolField)) return; 
      boolField = value; 
      OnPropertyChanged(); 
     } 
    } 

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) 
    { 
     var handler = PropertyChanged; 
     if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); 
    } 
} 

視圖模型：所以現在

public class MainViewModel : INotifyPropertyChanged 
{ 
    private ObservableCollection<SomeModel> models; 

    public ObservableCollection<SomeModel> Models 
    { 
     get { return models; } 
     set 
     { 
      if (Equals(value, models)) return; 
      models = value; 
      OnPropertyChanged(); 
     } 
    } 

    public event PropertyChangedEventHandler PropertyChanged; 

    public MainViewModel() 
    { 
     Models = new ObservableCollection<SomeModel>(); 
    } 

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) 
    { 
     var handler = PropertyChanged; 
     if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName)); 
    } 
} 

可以綁定模型的BoolField到複選框的值和TextBlock的風格二傳手在查看：

MainView.cs：

public partial class MainView : Window 
{ 
    public MainView() 
    { 

     InitializeComponent(); 
     var mv = new MainViewModel 
     { 
      Models = { new SomeModel { BoolField = true, TextField = "One" }, new SomeModel { TextField = "Two" } }, 
     }; 
     DataContext = mv; 

    } 
} 

MainView.xaml：

<Window x:Class="WpfDataGridCols.MainView" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="MainView" Height="350" Width="525"> 
<Grid> 
    <DataGrid ItemsSource="{Binding Models}" AutoGenerateColumns="False"> 
     <DataGrid.Columns> 
      <DataGridTextColumn Binding="{Binding TextField}"> 
       <DataGridTextColumn.ElementStyle> 
        <Style TargetType="TextBlock"> 
         <Setter Property="TextWrapping" Value="Wrap"/> 
         <Setter Property="TextAlignment" Value="Center" /> 
         <Style.Triggers> 
          <!--Pay attention on this:--> 
          <DataTrigger Binding="{Binding BoolField}" Value="True"> 
           <Setter Property="TextDecorations" Value="Strikethrough"/> 
          </DataTrigger> 
         </Style.Triggers> 
        </Style> 
       </DataGridTextColumn.ElementStyle> 
      </DataGridTextColumn> 
      <DataGridCheckBoxColumn Binding="{Binding BoolField}"/> 
     </DataGrid.Columns> 
    </DataGrid> 
</Grid>