.NET截断字符串

         /// <summary>
         /// 截断字符串
         /// </summary>
         /// <param name="s">要截断的字符串</param>
         /// <param name="len">要保留的字符长度</param>
         /// <returns>截断后的字符串</returns>
         public static string Format(string s, int len)
         {
             if (s.Length > len)
                 s = s.Substring(, len) + "...";
             return s;
         }