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);
}

C语言的一种方法:

char proper(char string[])
{
    int i = 0;

    for(i=0; i<=25; i++)
    {
        string[i] = tolower(string[i]);  // Converts all characters to lower case
        if(string[i-1] == ' ') // If the character before is a space
        {
            string[i] = toupper(string[i]); // Converts characters after spaces to upper case
        }
    }

    string[0] = toupper(string[0]); // Converts the first character to upper case
    return 0;
}

可参考微软。VisualBasic(也处理大写字符串):

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

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。

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);

在检查null或空字符串值以消除错误后，您可以直接使用这个简单的方法将文本或字符串更改为正确的:

// Text to proper (Title Case):
    public string TextToProper(string text)
    {
        string ProperText = string.Empty;
        if (!string.IsNullOrEmpty(text))
        {
            ProperText = CultureInfo.CurrentCulture.TextInfo.ToTitleCase(text);
        }
        else
        {
            ProperText = string.Empty;
        }
        return ProperText;
    }