如何拖放我使用WPF從一個組合框項目的WPF的文本框

內容如下WPF代碼如何拖放我使用WPF從一個組合框項目的WPF的文本框

<ComboBox Name="cmbFunctionsList" Grid.Row="3" Grid.Column="1" 
         DropDownClosed="OnCmbFunctionsListDropDownClosed" 
         DisplayMemberPath="FunctionItem" SelectedValuePath="FunctionValue" 
         PreviewMouseLeftButtonDown="OnFunctionsListPreviewMouseLeftButtonDown" 
         PreviewMouseMove="OnFunctionsListPreviewMouseMove"      
         MinHeight="25" Margin="2,2,2,0" VerticalAlignment="Center"/> 

<TextBox Grid.Column="1" Margin="2" Grid.Row="2" Grid.ColumnSpan="2" Name="txtExpression" 
      AllowDrop="True" Drop="OnTxtExpressionDrop" DragEnter="OnTxtExpressionDragEnter" /> 





private void OnFunctionsListPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     //storing the mouse position 
     _startPoint = e.GetPosition(null); 
    } 
private void OnFunctionsListPreviewMouseMove(object sender, MouseEventArgs e) 
{ 

    // Drag and Drop Code is commented 
    // Get the current mouse position 
    Point mousePos = e.GetPosition(null); 
    Vector diff = _startPoint - mousePos; 

    if (e.LeftButton == MouseButtonState.Pressed && 
     Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance || 
     Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance) 
    { 
     ComboBox cmb = sender as ComboBox; 
     cmb.StaysOpenOnEdit = true; 

     ComboBoxItem cmbItem = FindAnchestor<ComboBoxItem>((DependencyObject)e.OriginalSource); 

     if (cmbItem != null) 
     { 
      if (cmbFunctionsList.SelectedIndex > -1 && cmbFunctionsList.IsDropDownOpen == true) 
      { 
       // Find the data behind the ComboBoxItem 
       DataRowView dr = (DataRowView)cmb.ItemContainerGenerator.ItemFromContainer(cmbItem); 

       string draggedText = (String)dr[1]; 

       // Initialize the drag & drop operation 
       DataObject dragData = new DataObject("stringFormat", draggedText); 
       DragDrop.DoDragDrop(cmbItem, dragData, DragDropEffects.Copy); 
      } 
     } 
    } 
} 


private void OnTxtExpressionDragEnter(object sender, DragEventArgs e) 
     { 

      if (!e.Data.GetDataPresent("stringFormat") || sender == e.Source) 
      { 
       e.Effects = DragDropEffects.Copy; 
      } 

     } 

    private void OnTxtExpressionDrop(object sender, DragEventArgs e) 
     { 
      if (e.Data.GetDataPresent("stringFormat")) 
      { 
       String droppedText = e.Data.GetData("stringFormat") as String; 
       TextBox txtExp = sender as TextBox; 
       txtExp.Text = droppedText; 
      } 

     }

但仍拖放功能不能正常工作。此外，當我嘗試從comboBox拖動一個項目時，它會自動關閉。

你能向我推薦我在這裏失蹤的東西嗎？

來源

2011-08-23 Abhi

FindAncestor與RelativeSource綁定一起使用。我沒有看到任何RelativeSource綁定在這裏完成。 –

此鏈接可以幫助： http://stackoverflow.com/questions/1596797/wpf-drag-drop-on-listbox-item –

刪除事件在WPf中自動處理，因此無需編寫事件刪除或預覽刪除

來源

2011-08-30 05:52:06 Abhi

如何拖放我使用WPF從一個組合框項目的WPF的文本框

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