如果拖動或按住鼠標按鈕，發件人不會在MouseMove上更新

Question

我正在嘗試實現自定義拖動操作以對面板進行排序。

我將對象分配給MouseDown事件中的變量，並通過在將鼠標拖到相鄰面板上時檢查相鄰面板的MouseMove事件來跟蹤其相對位置。

Private Sub ThumbnailMouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

    _thumbnailMove = DirectCast(sender, Windows.Forms.Control)  ‘The object to move

End Sub

問題在於MouseMove事件的Sender參數永遠不會更改-它總是返回接收MouseDown事件的對象。

Private Sub ThumbnailMouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

    Console.WriteLine(sender.Name)  'Always returns the name of the _thumbnailToMove

End Sub

為什么MouseMove的Sender參數沒有返回鼠標當前所在的實際對象？

Answer 1

若要覆蓋此行為，請將Control.Capure屬性設置為False 。

Private Sub ThumbnailMouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)

    DirectCast(sender, Windows.Forms.Control).Capture = False   'Don't capture the mouse
    _thumbnailMove = DirectCast(sender, Windows.Forms.Control)

End Sub

現在，MouseMove事件將返回鼠標移過的實際對象！