[問(wèn)答題] 設(shè)已經(jīng)在菜單編輯器中設(shè)計(jì)了窗體的快捷菜單，某頂級(jí)菜單為a1，且取消其“可見(jiàn)”屬性。運(yùn)行時(shí)，哪個(gè)事件過(guò)程可以使快捷菜單的菜單項(xiàng)響應(yīng)鼠標(biāo)左鍵單擊和右健單擊的事件過(guò)程是

Ａ) Private Sub Form_MouseDown(Button As Integer，Shift As Integer，X As Single，Y As Single)

If Button=2 Then PopupMenu a1，2

End Sub

Ｂ) Private Sub Form_MouseDown(ButtonAsInteger，ShiftAsInteger，X As Single，Y As Single)

PopupMenu a1，0

End Sub

Ｃ) Private Sub Form_Mouse Down(Button As Integer，Shift As Integer，X As Single，Y As Single)

PopupMenu a1

End Sub

Ｄ) Private Sub Form_MouseDown(Button As Integer，Shift As Integer，X As Single，Y As Single)

If(Button=vbLetfButton) Or (Button=vbRightButton) Then PopupMenu a1

End Sub

C

MouseDown事件用來(lái)響應(yīng)鼠標(biāo)單擊，其中Button的參數(shù)用來(lái)確認(rèn)鼠標(biāo)按鈕(1：左鍵；2：右鍵)，PopupMenu方法用以在指定坐標(biāo)位置顯示彈出式菜單，語(yǔ)法如下：[對(duì)象].PopupMenu菜單名，標(biāo)志，x，y。 其中x，y提供菜單顯示位置，標(biāo)志指定快捷菜單的行為。