Question

VB在文本框中输入一个字符串,将其中的小写字符转换为大写字符,大写字符转换为小写字符,

Answer 1

若文本框是text1，则
text1.text = LCase(text1.text)
或简写
text1 = LCase(text1)

Answer 2

a = LCase("This Is A String") ' a 的值为 "this is a string"a = UCase("This Is A String") ' a 的值为 "THIS IS A STRING"

Answer 3

转换小写为大写：LCase函数，例如XX = LCase("abcd")，返回值：XX = "ABCD"
转换大写为小写：UCase函数，例如XX = UCase("ABCD")，返回值：XX = "abcd"
可以：XX = LCase(Text1.Text) 或 XX = UCase(Text1.Text)，全部转换为大写或小写；如果 Text1.Text 中的大写转换为小写，小写转换为大写，需要逐字符检测并转换。

代码如下：
Private Sub Command1_Click()
Dim XX As String, YY As String, ZZ As String, AA As Integer, I As Integer
XX = Text1.Text
AA = Len(XX)
For I = 1 To AA
ZZ = Mid(XX, I, 1)
If Asc(ZZ) >= 65 And Asc(ZZ) <= 90 Then
ZZ = LCase(ZZ)
ElseIf Asc(ZZ) >= 97 And Asc(ZZ) <= 122 Then
ZZ = UCase(ZZ)
End If
YY = YY & ZZ
Next I
Text1.Text = YY
End Sub

Answer 4

百度不是廉价的回答！！有作用吗？

Answer 5

那个都行。