17.要求將某一字符串中指定的字符改寫成小寫或大寫(如果原先是大寫就改成小寫,反之改成大寫),并將處理后的字符重新輸出.程序界面如圖所示,在Text1中輸入原始字符串,在Text2中輸入需要改變的字符,單機(jī)“改變”按鈕后,在Text3中輸出處理后的結(jié)果.程序代碼如下:
Private Sub Command1_Click ( ?。?br />Dim s As String,result As String,k As String
Dim zs As String,n As Integer
result=““
s=Text1.Text
k=Text2.Text
For n=1To Len(s)
If zs=k Then
If Asc(zs)>=65And Asc(zs)<=90Then
zs=Chr(Asc(zs)+32)
ElseIf Asc(zs)>=97And Asc(zs)<=122Then
zs=Chr(Asc(zs)-32)
End If
End If
Next n
End Sub.