vb.net - 在 visual basic 中使用 toupper 和 tolower

Question

试图通过此更改已解析字符串段首字母的大小写。因此，如果用户在 txtName 中输入“JOHN WAYNE DOE”，那么它将显示“John Wayne Doe”我按照书中显示的方式输入了它，但是消息框显示了已解析的字符串，但是它是输入的，因此在上面的示例中返回的是“JOHN WAYNE DOE”我认为这是一个逻辑错误，因为众所周知我经常这样做只是不知道我在哪里犯了错误。

    Dim name As String = txtName.Text
    name = name.Trim
    Dim names() As String = name.Split(CChar(" "))
    Dim firstName As String = names(0)
    Dim middleName As String = names(1)
    Dim lastName As String = names(2)

    Dim firstLetters1 As String = firstName.Substring(0, 1).ToUpper
    Dim otherletters1 As String = firstName.Substring(1).ToLower

    Dim firstLetters2 As String = middleName.Substring(0, 1).ToUpper
    Dim otherletters2 As String = middleName.Substring(1).ToLower

    Dim firstletters3 As String = lastName.Substring(0, 1).ToUpper
    Dim otherletters3 As String = lastName.Substring(1).ToLower

    MessageBox.Show("First Name: " & firstName & vbCrLf & "Middle Name: " & middleName & vbCrLf & "Last Name: " & lastName)

Answer 1

只是提一下这个选择

Dim currentCulture As CultureInfo = System.Threading.Thread.CurrentThread.CurrentCulture 
Dim titleCase = currentCulture.TextInfo.ToTitleCase(txtName.Text)
Console.WriteLine(titleCase)
Dim names() As String = titleCase.Split(" "c)
......

此方法确保字符串的正确大小写符合当前文化。
并且不需要那么多具有固有内存占用的直接拆分和字符串连接。 (在内部，一个 StringBuilder 用于操作输入字符串，只有一个最终的 ToString() 返回结果)