问题详情

在窗体中添加两个文本框，其名称分别为Text1和Text2;两个标签，其名称分别为Label1和Label2。编写程序，使得程序运行后，在文本框Text2中输入小写字母，能转换为比此字母的ASCII码小4的大写字母，结果显示在文本框Text1中。如输入“efg”，则输出的结果为“ABC”，能够实现上述功能的程序是
A．Private Sub Form. Load() Show Text1．Text=" " Text2．Text=" " Text2．SetFocus End Sub Private Sub Text2_KeyDown(KeyCode As Integer，Shift As Integer) Text1．Text=Chr(KeyCode-4) End Sub
B．Private Sub Form_Load() Show Text1．Text=" " Text2．Text=" " Text2．SetFocus End Sub Private Sub Text2_KeyDown(KeyCode As Integer，Shift As Integer) Text1．Text=Text1．Text+Chr(KeyCode-4) End Sub
C．Private Sub Form_Load() Show Text1．Text=" " Text2．Text=" " Text2．SetFocus End Sub Private Sub Text2_Click(KeyCode As Integer，Shift As Integer) Text1．Text=Text1．Text+Chr(KeyCOde-4) End Sub
D．Private Sub Form_Load() Show Text1．Text=" " Text2．Text=" " Text2．SetFocus End Sub Private Sub Text2_Click(KeyCode As Integer，Shift As Integer) Text1．Text=Chr(KeyCode-4) End Sub请帮忙给出正确答案和分析，谢谢！