为什么一个结果是0，一个是10？ 第一段： Private Sub Form_Click() Dim a As Integer For i = 1 To 10 Call abcd(a) Next i Print a End Sub Sub abcd(ByVal x) x = x + 1 End Sub 第二段： Private Sub Form_Click() Dim a As Integer For i = 1 To 10 Call abcd(a) Next i Print a End Sub [...]