关于vb 大小写转换

Private Sub Text1_Change()
'变量声明时注意定义变量类型
Dim X As String
Dim I As Long
Dim S As String '把后面代码中的S1改为S
Dim CH As String

X = Text1.Text '赋值语句应该把变量放在前面
For I = 1 To Len(X)
CH = Mid(X, I, 1)
If CH >= "a " And CH <= "z" Then '此处的“a ”多了一个空格，虽然程序运行时没有出错……
S = S + UCase(CH)
ElseIf CH >= "A" And CH <= "Z" Then
S = S + LCase(CH)
End If
Next I
Text2.Text = S
End Sub

Private Sub Text1_Change()
Dim X As String
Dim I As Long
Dim S1 As String
Dim CH As String

S1 = ""
X = Text1.Text
For I = 1 To Len(X)
CH = Mid(X, I, 1)
If CH >= "a" And CH <= "z" Then
S1 = S1 + UCase(CH)
ElseIf CH >= "A" And CH <= "Z" Then
S1 = S1 + LCase(CH)
End If
Next I
Text2.Text = S1

End Sub

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