就我个人而言，我尝试了TextInfo。ToTitleCase方法，但是，我不明白为什么当所有字符都是大写的时候它不起作用。

虽然我喜欢Winston Smith提供的util函数，但让我提供我目前正在使用的函数:

public static String TitleCaseString(String s)
{
    if (s == null) return s;

    String[] words = s.Split(' ');
    for (int i = 0; i < words.Length; i++)
    {
        if (words[i].Length == 0) continue;

        Char firstChar = Char.ToUpper(words[i][0]); 
        String rest = "";
        if (words[i].Length > 1)
        {
            rest = words[i].Substring(1).ToLower();
        }
        words[i] = firstChar + rest;
    }
    return String.Join(" ", words);
}

玩一些测试字符串:

String ts1 = "Converting string to title case in C#";
String ts2 = "C";
String ts3 = "";
String ts4 = "   ";
String ts5 = null;

Console.Out.WriteLine(String.Format("|{0}|", TitleCaseString(ts1)));
Console.Out.WriteLine(String.Format("|{0}|", TitleCaseString(ts2)));
Console.Out.WriteLine(String.Format("|{0}|", TitleCaseString(ts3)));
Console.Out.WriteLine(String.Format("|{0}|", TitleCaseString(ts4)));
Console.Out.WriteLine(String.Format("|{0}|", TitleCaseString(ts5)));

给输出:

|Converting String To Title Case In C#|
|C|
||
|   |
||

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;
    }

可参考微软。VisualBasic(也处理大写字符串):

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

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;
        }
    }

}

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);

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);
}