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);

对于那些想要自动按下键盘的人，我用下面的VB代码做到了。NET在一个自定义文本框控件上-你显然也可以用一个普通的文本框来做-但是我喜欢通过自定义控件为特定控件添加循环代码的可能性，它适合OOP的概念。

Imports System.Windows.Forms
Imports System.Drawing
Imports System.ComponentModel

Public Class MyTextBox
    Inherits System.Windows.Forms.TextBox
    Private LastKeyIsNotAlpha As Boolean = True
    Protected Overrides Sub OnKeyPress(e As KeyPressEventArgs)
        If _ProperCasing Then
            Dim c As Char = e.KeyChar
            If Char.IsLetter(c) Then
                If LastKeyIsNotAlpha Then
                    e.KeyChar = Char.ToUpper(c)
                    LastKeyIsNotAlpha = False
                End If
            Else
                LastKeyIsNotAlpha = True
            End If
        End If
        MyBase.OnKeyPress(e)
End Sub
    Private _ProperCasing As Boolean = False
    <Category("Behavior"), Description("When Enabled ensures for automatic proper casing of string"), Browsable(True)>
    Public Property ProperCasing As Boolean
        Get
            Return _ProperCasing
        End Get
        Set(value As Boolean)
            _ProperCasing = value
        End Set
    End Property
End Class

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;
}

public static string PropCase(string strText)
{
    return new CultureInfo("en").TextInfo.ToTitleCase(strText.ToLower());
}

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|
||
|   |
||

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);