阅读下列程序: Dim SW As Boolean Function func(X As Integer)As Integer If X<20 Then Y=X Else Y=20+X End If func=Y End Function Private Sub Form_MouseDown(Button As Integer,Shift As Integer,X As Single, Y As Single)SW=False End Sub Private Sub Form_MouseUp(Button As Integer,Shift As Integer,X As Single, Y As Single)SW=True End Sub Private Sub Command1_Click()Dim intNum As IntegerintNum=InputBox(" ")If SW Then Print func(intNum)End If End Sub 程序运行后,单击一次窗体,再单击命令按钮,将显示一个输入对话框,如果在对话框中输入20,则程序的输出结果为
A.0
B.20
C.40
D.无任何输出