static void Test7()
        {
            //1970-01-01的Ticks值
            long tStart = 621355968000000000;
            //方法1，直接相减
            long ts1 = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0)).Ticks;
            //方法2，将当前时间转换为Utc时间，再减
            long ts2 = DateTime.Now.ToUniversalTime().Ticks - tStart;
            //方法3，直接获取当前Utc时间，再减
            long ts3 = DateTime.UtcNow.Ticks - tStart;


            var ret1 = ts1 / 10000000;
            var ret2 = ts1 / 10000;

            Console.WriteLine(ret1);//10位
            Console.WriteLine(ret2);//13位
        }

        /// <summary>
        /// 获取时间戳，TimeSpan
        /// </summary>
        static void Test6()
        {
            //1970-01-01的Ticks值
            long tStart = 621355968000000000;
            //方法1，直接相减
            TimeSpan ts1 = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
            //方法2，将当前时间转换为Utc时间，再减
            TimeSpan ts2 = new TimeSpan(DateTime.Now.ToUniversalTime().Ticks - tStart);
            //方法3，直接获取当前Utc时间，再减
            TimeSpan ts3 = new TimeSpan(DateTime.UtcNow.Ticks - tStart);

            var ret1 = Convert.ToInt64(ts1.TotalSeconds);
            var ret2 = Convert.ToInt64(ts1.TotalMilliseconds);

            Console.WriteLine(ret1);//10位
            Console.WriteLine(ret2);//13位
        }

        static void Test8()
        {
            long ret1 = 1593488038;
            long ret2 = 1593488038297;
            var ret10 = ret1 * 10000000;
            var ret20 = ret2 * 10000;
            DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));

            TimeSpan ts1 = new TimeSpan(ret10);
            var dt1 = dtStart.Add(ts1);
            TimeSpan ts2 = new TimeSpan(ret20);
            var dt2 = dtStart.Add(ts2);

            Console.WriteLine(dt1.ToString("yyyy-MM-dd HH:mm:ss.ffff"));
            Console.WriteLine(dt2.ToString("yyyy-MM-dd HH:mm:ss.ffff"));
        }