单项选择题

将窗体的KeyPreview属性设置为True,然后编写如下过程: Private Sub Form KeyDown(KeyCode As Integer,Shift As Integer) Print Chr(KeyCode) End Sub Private Sub Form_KeyUp(KeyCode As Integer,Shift As Integer) Print Chr(KeyCode+2) End Sub 程序运行后,如果按“A”键,则输出的结果为

A.A A
B.A B
C.A C
D.A D