幫助註冊依賴屬性

Question

我創建了自己的DataGrid控件，它繼承自DataGrid。我聲明瞭一個我想在列級使用的Dependency Property，因此在PreviewKeyDown事件中，我檢查該值並決定是否需要處理當前單元格。

public class MyDataGrid : DataGrid 
{ 
    public static DependencyProperty HandleKeyPressEventProperty = 
     DependencyProperty.RegisterAttached(
      "HandleKeyPressEvent", 
      typeof(bool), 
      typeof(MyDataGrid), 
      new FrameworkPropertyMetadata(true)); 

    public bool HandleKeyPressEvent 
    { 
     get { return (bool)GetValue(HandleKeyPressEventProperty); } 
     set { SetValue(HandleKeyPressEventProperty, value); } 
    } 

    protected override void OnPreviewKeyDown(KeyEventArgs e) 
    { 
     if (HandleKeyPressEvent) 
     { 
      HandleKeyPress(e); 
     } 
     else 
     { 
      base.OnPreviewKeyDown(e); 
     } 
    } 
} 

我的XAML看起來像這樣：

<MyDataGrid x:Name="myDataGrid"> 
    <DataGridTextColumn MyDataGrid.HandleKeyPressEvent = "True" /> 
    <DataGridTemplateColumn MyDataGrid.HandleKeyPressEvent = "False"/> 
</MyDataGrid> 

，但我有一個真正的問題有在列級可用此依賴項屬性。我試圖做的就像Grid.Column。有人可以幫助我嗎？

Answer 1

附加屬性具有靜態Get方法和靜態Set方法（由屬性名稱前綴爲Get/Set），而不是CLR屬性包裝器。要檢查當前列OnPreviewKeyDown，您可以使用CurrentCell.Column

public class MyDataGrid : DataGrid 
{ 
    public static readonly DependencyProperty HandleKeyPressEventProperty = 
     DependencyProperty.RegisterAttached("HandleKeyPressEvent", 
              typeof(bool), 
              typeof(MyDataGrid), 
              new UIPropertyMetadata(true)); 
    public static bool GetHandleKeyPressEvent(DependencyObject obj) 
    { 
     return (bool)obj.GetValue(HandleKeyPressEventProperty); 
    } 
    public static void SetHandleKeyPressEvent(DependencyObject obj, bool value) 
    { 
     obj.SetValue(HandleKeyPressEventProperty, value); 
    } 
    protected override void OnPreviewKeyDown(KeyEventArgs e) 
    { 
     if (GetHandleKeyPressEvent(CurrentCell.Column) == true) 
     { 
      HandleKeyPress(e); 
     } 
     else 
     { 
      base.OnPreviewKeyDown(e); 
     } 
    } 
}