VB.NET 如何处理一个事件中的触发控件来源
比如：
Private Sub GroupBox1_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles GroupBox1.DragDrop, GroupBox2.DragDrop, GroupBox3.DragDrop, GroupBox4.DragDrop, GroupBox5.DragDrop, GroupBox6.DragDrop, GroupBox7.DragDrop _
, GroupBox8.DragDrop, GroupBox9.DragDrop, GroupBox10.DragDrop, GroupBox11.DragDrop, GroupBox12.DragDrop, GroupBox13.DragDrop, GroupBox14.DragDrop, GroupBox15.DragDrop, GroupBox16.DragDrop, GroupBox17.DragDrop, GroupBox18.DragDrop, GroupBox19.DragDrop _
, GroupBox20.DragDrop, GroupBox21.DragDrop, GroupBox22.DragDrop, GroupBox23.DragDrop, GroupBox24.DragDrop
Dim s() As String
s = e.Data.GetData(System.Windows.Forms.DataFormats.FileDrop)
MsgBox(Join(s, ","), , GroupBox1.Text)
End Sub

这里我用VB.NET的特性，使得这个过程可以处理多个控件的事件。我如何可以获得是哪个控件触发的事件？

[解决办法]
sender 参数就是控件对象呀。