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。

我使用了上面的参考，一个完整的解决方案是:

Use Namespace System.Globalization;
string str = "INFOA2Z means all information";

//需要类似"Infoa2z意味着所有信息"的结果 //我们也需要转换小写的字符串，否则它不能正常工作。

TextInfo ProperCase = new CultureInfo("en-US", false).TextInfo;

str = ProperCase.ToTitleCase(str.toLower());

在ASP中更改字符串为正确的大小写。NET使用c#

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

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。

最近我找到了一个更好的解决方案。

如果文本中每个字母都是大写的，那么TextInfo将不会将其转换为正确的大小写。我们可以通过使用里面的小写函数来解决这个问题，就像这样:

public static string ConvertTo_ProperCase(string text)
{
    TextInfo myTI = new CultureInfo("en-US", false).TextInfo;
    return myTI.ToTitleCase(text.ToLower());
}

现在这将把所有输入的内容转换为Propercase。

下面是一个逐字符的实现。它应该和"(一二三)"一起工作：

public static string ToInitcap(this string str)
{
    if (string.IsNullOrEmpty(str))
        return str;
    char[] charArray = new char[str.Length];
    bool newWord = true;
    for (int i = 0; i < str.Length; ++i)
    {
        Char currentChar = str[i];
        if (Char.IsLetter(currentChar))
        {
            if (newWord)
            {
                newWord = false;
                currentChar = Char.ToUpper(currentChar);
            }
            else
            {
                currentChar = Char.ToLower(currentChar);
            }
        }
        else if (Char.IsWhiteSpace(currentChar))
        {
            newWord = true;
        }
        charArray[i] = currentChar;
    }
    return new string(charArray);
}