Question

VB中，用If语句编写大小写字母转换程序，急用

输入大写字母，转换为小写，输入小写，转换为大写。输入非字母则不做处理

Answer 1

是只输入一个字母吗？（如果是，代码如下）如果是要输入字符串，可追问
Private Sub Command1_Click()
n = Asc(Text1.Text)
If n >= 65 And n <= 90 Then
n = n + 32
Text1.Text = Chr(n)
ElseIf n >= 97 And n <= 122 Then
n = n - 32
Text1.Text = Chr(n)
End If
End Sub

Answer 2

'你说的是要用一个IF语句吗？
Function Switch(S As String) As String
Switch = IIf(S >= "a" And S <= "z", UCase(S), IIf(S >= "A" And S <= "Z", LCase(S), S))
End Function