vb.net大小写字母转换

我定义了一个变量，是STRING，如：0gf0ajkh04624v，是小写字母和数字混合组成的，如何使其中的小写字母转换成大写字母？

Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
Dim s As String = "0Ff0ajkh04624F"
Dim i As Integer = 0
Dim sTemp As String = ""
Dim ss As String = ""

For i = 1 To Strings.Len(s)
sTemp = Mid(s, i, 1)
If Asc(sTemp) >= 65 And Asc(sTemp) <= 90 Then
sTemp = LCase(sTemp)
ElseIf Asc(sTemp) >= 95 And Asc(sTemp) <= 122 Then
sTemp = UCase(sTemp)
Else
sTemp = sTemp
End If
ss = ss & sTemp
Next

MsgBox(ss)

End Sub

界面如图:

代码为 :

private sub command1_click() text4 = replace(text1, text2, text3,1) end sub

Dim str As String = "0gf0ajkh04624v" MsgBox(str .ToUpper()) 'ToUpper是把小写字母转换成大写