在WPF中的兩個Datagrid之間拖放（C＃）

Question

對不起，我的英文不是我的母語。請告訴我，如果你不明白的東西。

我開始C＃和WPF，我需要實現兩個數據網格之間的拖放功能。我已經搜索了很多，但我沒有找到任何幫助我的東西。它總是顯示如何在兩個不同的控件之間進行拖放操作，或者只在同一個數據網格中進行拖放操作，而且我無法將這些答案適應於我的需求，因爲我不瞭解解決方案的某些部分。 所以我來這裏問一個非常精確的問題：如何實現兩個DataGrid之間的拖放？

如果你能幫助我，我將不勝感激。

Answer 1

此一個示例代碼（More Details here）

1. 定義mouseDown事件
2. 定義mousemove事件開始DragAndDrop操作
3. 定義的dragover以測試是否下降允許或不允許
4. 定義Drop事件做刪除操作

您可以對兩個數據網格使用相同的事件

private Point? _startPoint; 

    private void dataGrid_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     _startPoint = e.GetPosition(null); 
    } 

    private void dataGrid_PreviewMouseMove(object sender, MouseEventArgs e) 
    { 
     // No drag operation 
     if (_startPoint == null) 
      return; 

     var dg = sender as DataGrid; 
     if (dg == null) return; 
     // Get the current mouse position 
     Point mousePos = e.GetPosition(null); 
     Vector diff = _startPoint.Value - mousePos; 
     // test for the minimum displacement to begin the drag 
     if (e.LeftButton == MouseButtonState.Pressed && 
      (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance || 
      Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance)) 
     { 

      // Get the dragged DataGridRow 
      var DataGridRow= 
       FindAnchestor<DataGridRow>((DependencyObject)e.OriginalSource); 

      if (DataGridRow == null) 
       return; 
      // Find the data behind the DataGridRow 
      var dataTodrop = (DataModel)dg.ItemContainerGenerator. 
       ItemFromContainer(DataGridRow); 

      if (dataTodrop == null) return; 

      // Initialize the drag & drop operation 
      var dataObj = new DataObject(dataTodrop); 
      dataObj.SetData("DragSource", sender); 
      DragDrop.DoDragDrop(dg, dataObj, DragDropEffects.Copy); 
      _startPoint = null; 
     } 
    } 

    private void dataGrid_PreviewMouseUp(object sender, MouseButtonEventArgs e) 
    { 
     _startPoint = null; 
    } 

    private void dataGrid_Drop(object sender, DragEventArgs e) 
    { 
     var dg = sender as DataGrid; 
     if (dg == null) return; 
     var dgSrc = e.Data.GetData("DragSource") as DataGrid; 
     var data = e.Data.GetData(typeof(DataModel)); 
     if (dgSrc == null || data == null) return; 
     // Implement move data here, depends on your implementation 
     MoveDataFromSrcToDest(dgSrc, dg, data); 
     // OR 
     MoveDataFromSrcToDest(dgSrc.DataContext, dg.DataContext, data); 
    } 

    private void dataGrid_PreviewDragOver(object sender, DragEventArgs e) 
    { 
     // TO test if drop is allowed, to avoid drop 
     // if false e.Effects = DragDropEffects.None; 
    } 


    // Helper to search up the VisualTree 
    private static T FindAnchestor<T>(DependencyObject current) 
     where T : DependencyObject 
    { 
     do 
     { 
      if (current is T) 
      { 
       return (T)current; 
      } 
      current = VisualTreeHelper.GetParent(current); 
     } 
     while (current != null); 
     return null; 
    } 

希望這有助於:)