c# 正则表达式 首字母转大写

     class Program
     {
         static void Main(string[] args)
         {
             // Input strings.
             const string s1 = "samuel allen";
             const string s2 = "dot net perls";
             const string s3 = "Uppercase first letters of all words in the string.";

             // Write output strings.
             Console.WriteLine(TextTools.UpperFirst(s1));
             Console.WriteLine(TextTools.UpperFirst(s2));
             Console.WriteLine(TextTools.UpperFirst(s3));
             Console.ReadKey();
         }
     }

     public static class TextTools
     {
         /// <summary>
         /// Uppercase first letters of all words in the string.
         /// </summary>
         public static string UpperFirst(string s)
         {
             return Regex.Replace(s, @"\b[a-z]\w+", delegate(Match match)
             {
                 string v = match.ToString();
                 return char.ToUpper(v[]) + v.Substring();
             });
         }
     }