Private Sub TextBox_TextChanged(ByVal sender As System.Object, ByVal e As _
     System.EventArgs) Handles TextBox3.TextChanged, TextBox2.TextChanged, _
     TextBox1.TextChanged
      If Not TypeOf sender Is TextBox Then Exit Sub
 
      Dim currentTextBox As TextBox = DirectCast(sender, TextBox)
 
      Debug.WriteLine(currentTextBox.Text) ' oder eben anderer Code mit dem 
      ' Control
   End Sub