获取时间戳

 /// <summary> 
        /// 获取时间戳 
        /// </summary> 
        /// <returns></returns> 
        public static string GetTimeStamp()
        {
            TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
            return Convert.ToInt64(ts.TotalMilliseconds).ToString();
        }