WPF從列表框中拖放對象

Question

初學者在這裏。

我試圖創建一個用戶控件與在其他控制一個列表框，我想這個列表框允許拖放到該用戶控件的其他類似的實例。

這是另一個我想拖動對象，從一個列表框下拉：

[Serializable] 
public class ListBoxFileName : INotifyPropertyChanged 
{ 
    public event PropertyChangedEventHandler PropertyChanged; 

    private void NotifyPropertyChanged(String info) 
    { 
     if (PropertyChanged != null) 
     { 
      PropertyChanged(this, new PropertyChangedEventArgs(info)); 
     } 
    } 

    private string FileNameValue; 
    public string FileName 
    { 
     get { return this.FileNameValue; } 

     set 
     { 
      if (value != this.FileNameValue) 
      { 
       this.FileNameValue = value; 
       NotifyPropertyChanged("FileName"); 
      } 
     } 
    } 

    private bool FileIsSelectedValue; 
    public bool FileIsSelected 
    { 
     get { return this.FileIsSelectedValue; } 

     set 
     { 
      if (value != this.FileIsSelectedValue) 
      { 
       this.FileIsSelectedValue = value; 
       NotifyPropertyChanged("FileIsSelected"); 
      } 
     } 
    } 
} 

這裏是我如何處理拖放：

private ListBoxItem _dragged; 

    private void FileNameList_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     if (_dragged != null) 
      return; 

     UIElement element = FileNameList.InputHitTest(e.GetPosition(FileNameList)) as UIElement; 
     while (element != null) 
     { 
      if (element is ListBoxItem) 
      { 
       _dragged = (ListBoxItem)element; 
       break; 
      } 
      element = VisualTreeHelper.GetParent(element) as UIElement; 
     } 
    } 


    private void Window_MouseMove(object sender, MouseEventArgs e) 
    { 
     if (_dragged == null) 
      return; 
     if (e.LeftButton == MouseButtonState.Released) 
     { 
      _dragged = null; 
      return; 
     } 
     DataObject obj = new DataObject(DataFormats.Serializable, _dragged); 
     DragDrop.DoDragDrop(_dragged, obj, DragDropEffects.All); 
    } 

    private void FileNameList_DragEnter(object sender, DragEventArgs e) 
    { 
     if (_dragged == null || e.Data.GetDataPresent(DataFormats.Serializable, true) == false) 
      e.Effects = DragDropEffects.None; 
     else 
      e.Effects = DragDropEffects.All; 
    } 

    private void FileListBox_Drop(object sender, DragEventArgs e) 
    { 
     if (e.Data.GetDataPresent(DataFormats.FileDrop, true)) 
     { 
      string[] droppedFilePaths = e.Data.GetData(DataFormats.FileDrop, true) as string[]; 
      for (var i = 0; i < droppedFilePaths.Length; i++) 
      { 
       ListBoxFileName filename = new ListBoxFileName(); 
       filename.FileName = droppedFilePaths[i]; 
       filename.FileIsSelected = false; 
       FileNamesItems.Add(filename); 
      } 
     } 
     if (e.Data.GetDataPresent(DataFormats.Serializable, true)) 
     { 
      ListBoxFileName BoxItem = new ListBoxFileName(); 
      BoxItem = e.Data.GetData(DataFormats.Serializable) as ListBoxFileName; 
     } 
    } 

一切除了當細發生丟棄事件，BoxItem由於某種原因始終爲空，因此沒有任何內容添加到列表框中。

任何提示？

謝謝

Answer 1

的數據對象的數據應該是一個ListBoxFileName，而不是一個ListBoxItem：

private void Window_MouseMove(object sender, MouseEventArgs e) 
{ 
    if (_dragged == null) 
     return; 
    if (e.LeftButton == MouseButtonState.Released) 
    { 
     _dragged = null; 
     return; 
    } 
    DataObject obj = new DataObject(DataFormats.Serializable, _dragged.DataContext as ListBoxFileName); 
    DragDrop.DoDragDrop(_dragged, obj, DragDropEffects.All); 
} 

private void FileListBox_Drop(object sender, DragEventArgs e) 
{ 
    if (e.Data.GetDataPresent(DataFormats.Serializable, true)) 
    { 
     ListBoxFileName BoxItem = e.Data.GetData(DataFormats.Serializable) as ListBoxFileName; 
     //... 
    } 
} 

這應該假設「FileNameList」控制的ItemsSource設置爲一個IEnumerable。

請提供能夠從頭開始重現您的問題，如果您需要在此進一步幫助需要所有相關的代碼片段。