删除单元格内容时删除键被按下

问题描述：

我如何能实现在.NET 4的DataGrid以下任何想法：删除单元格内容时删除键被按下

private void grid_KeyDown(object sender, KeyEventArgs e) 
{ 
    if (e.Key == Key.Delete) 
    { 
     DataGridCell cell = e.OriginalSource as DataGridCell; 

     if (cell == null) { return; } 

     if (!cell.IsReadOnly && cell.IsEnabled) 
     { 
      // Set the cell content (and the property of the object binded to it) 
      // to null 
     } 
    } 
}

这种行为应该与任何细胞工作，所以我不不想硬编码列或属性名称。

编辑：解决方案，我想出了：

if (e.Key == Key.Delete) 
{ 
    DataGridCell cell = e.OriginalSource as DataGridCell; 

    if (cell == null) { return; } 

    if (!cell.IsReadOnly && cell.IsEnabled) 
    { 
      TextBlock tb = cell.Content as TextBlock; 

      if (tb != null) 
      { 
       Binding binding = BindingOperations.GetBinding(tb, TextBlock.TextProperty); 

       if (binding == null) { return; } 

       BindingExpression exp = BindingOperations.GetBindingExpression(tb, TextBlock.TextProperty); 

       PropertyInfo info = exp.DataItem.GetType().GetProperty(binding.Path.Path); 

       if (info == null) { return; } 

       info.SetValue(exp.DataItem, null, null); 
      } 
    } 
}

答

这可能是相当复杂的，这取决于电池的模板等

我想像你不得不使用各种BindingOperations方法（BindingOperations.GetBinding，BindingOperations.GetBindingExpression等）弄乱绑定值？

答

有几件事情我必须做的就是这个工作：

编辑筛选出时删除按键（找不到一个明显的方式在编辑模式下，如果检测）：

private bool _isEditing = false; 
private void datagrid_BeginningEdit(object sender, DataGridBeginningEditEventArgs e) 
{ _isEditing = true; } 

private void datagrid_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e) 
{ _isEditing = false; }

拉手的KEYUP消息（的KeyDown消息是由数据网格处理）：

private void dataGrid_KeyUp(object sender, KeyEventArgs e) 
{ 
    if (!_isEditing && e.Key == Key.Delete && Keyboard.Modifiers == ModifierKeys.None) 
    { 
     foreach (var cellInfo in dataGrid.SelectedCells) 
     { 
      var column = cellInfo.Column as DataGridBoundColumn; 
      if (column != null) 
      { 
       var binding = column.Binding as Binding; 
       if (binding != null) 
        BindingHelper.SetSource(cellInfo.Item, binding, null); 
      } 
     } 
    } 
}

使用框架辅助类路由该值= null以底层视图模型

public class BindingHelper: FrameworkElement 
{ 
    public static void SetSource(object source, Binding binding, object value) 
    { 
     var fe = new BindingHelper(); 
     var newBinding = new Binding(binding.Path.Path) 
     { 
      Mode = BindingMode.OneWayToSource, 
      Source = source, 
     }; 
     fe.SetBinding(ValueProperty, newBinding); 
     fe.Value = value; 
    } 

    #region Value Dependency Property 
    public object Value 
    { 
     get { return (object)GetValue(ValueProperty); } 
     set { SetValue(ValueProperty, value); } 
    } 

    public static readonly DependencyProperty ValueProperty = 
     DependencyProperty.Register("Value", typeof(object), typeof(BindingHelper)); 
    #endregion 
}

删除单元格内容时删除键被按下

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