.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(0, len) + "...";
            return s;
        }