执行下列程序后，鼠标单击窗体，输出结果为 Private Sub Form_Click() Print"Click"： End Sub Private Sub Form_MouseDown(Button As Integer，Shift_As Integer，X As Single，Y As Single) Print"Donw" End Sub Private Sub Form_MouseUp(Button As Integer，Shift_As Integer，X As Single，Y As Single) Print"Up" End Sub