试试这个:

using System.Globalization;
using System.Threading;
public void ToTitleCase(TextBox TextBoxName)
        {
            int TextLength = TextBoxName.Text.Length;
            if (TextLength == 1)
            {
                CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
                TextInfo textInfo = cultureInfo.TextInfo;
                TextBoxName.Text = textInfo.ToTitleCase(TextBoxName.Text);
                TextBoxName.SelectionStart = 1;
            }
            else if (TextLength > 1 && TextBoxName.SelectionStart < TextLength)
            {
                int x = TextBoxName.SelectionStart;
                CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
                TextInfo textInfo = cultureInfo.TextInfo;
                TextBoxName.Text = textInfo.ToTitleCase(TextBoxName.Text);
                TextBoxName.SelectionStart = x;
            }
            else if (TextLength > 1 && TextBoxName.SelectionStart >= TextLength)
            {
                CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
                TextInfo textInfo = cultureInfo.TextInfo;
                TextBoxName.Text = textInfo.ToTitleCase(TextBoxName.Text);
                TextBoxName.SelectionStart = TextLength;
            }
        }

在TextBox的TextChanged事件中调用此方法。

最好通过尝试自己的代码来理解…

阅读更多

http://www.stupidcodes.com/2014/04/convert-string-to-uppercase-proper-case.html

1)将字符串转换为大写

string lower = "converted from lowercase";
Console.WriteLine(lower.ToUpper());

2)将字符串转换为小写

string upper = "CONVERTED FROM UPPERCASE";
Console.WriteLine(upper.ToLower());

3)转换String为TitleCase

    CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
    TextInfo textInfo = cultureInfo.TextInfo;
    string txt = textInfo.ToTitleCase(TextBox1.Text());

可参考微软。VisualBasic(也处理大写字符串):

string properCase = Strings.StrConv(str, VbStrConv.ProperCase);

下面是这个问题的解决方案……

CultureInfo cultureInfo = Thread.CurrentThread.CurrentCulture;
TextInfo textInfo = cultureInfo.TextInfo;
string txt = textInfo.ToTitleCase(txt);

我需要一种方法来处理所有大写单词，我喜欢Ricky AH的解决方案，但我进一步将其实现为扩展方法。这避免了必须创建字符数组然后每次显式调用ToArray的步骤-所以你可以只在字符串上调用它，如下所示:

用法:

string newString = oldString.ToProper();

代码:

public static class StringExtensions
{
    public static string ToProper(this string s)
    {
        return new string(s.CharsToTitleCase().ToArray());
    }

    public static IEnumerable<char> CharsToTitleCase(this string s)
    {
        bool newWord = true;
        foreach (char c in s)
        {
            if (newWord) { yield return Char.ToUpper(c); newWord = false; }
            else yield return Char.ToLower(c);
            if (c == ' ') newWord = true;
        }
    }

}

这就是我所使用的，它适用于大多数情况，除非用户决定通过按shift或caps lock覆盖它。比如Android和iOS键盘。

Private Class ProperCaseHandler
    Private Const wordbreak As String = " ,.1234567890;/\-()#$%^&*€!~+=@"
    Private txtProperCase As TextBox

    Sub New(txt As TextBox)
        txtProperCase = txt
        AddHandler txt.KeyPress, AddressOf txtTextKeyDownProperCase
    End Sub

    Private Sub txtTextKeyDownProperCase(ByVal sender As System.Object, ByVal e As Windows.Forms.KeyPressEventArgs)
        Try
            If Control.IsKeyLocked(Keys.CapsLock) Or Control.ModifierKeys = Keys.Shift Then
                Exit Sub
            Else
                If txtProperCase.TextLength = 0 Then
                    e.KeyChar = e.KeyChar.ToString.ToUpper()
                    e.Handled = False
                Else
                    Dim lastChar As String = txtProperCase.Text.Substring(txtProperCase.SelectionStart - 1, 1)

                    If wordbreak.Contains(lastChar) = True Then
                        e.KeyChar = e.KeyChar.ToString.ToUpper()
                        e.Handled = False
                    End If
                End If

            End If

        Catch ex As Exception
            Exit Sub
        End Try
    End Sub
End Class