DateTime与timeStamp的转换

DateTime转换为timeStamp：

DateTime dt = DateTime.Now;
            DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
            TimeSpan timeSpan = dt.Subtract(startTime);
            string timeStamp = timeSpan.Ticks.ToString();
            return timeStamp.Substring(0, timeStamp.Length - 7);

timeStamp转换为DateTime：

string timeStamp = "1144821796";
            DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970,1,1));
            long lTime = long.Parse(timeStamp + "0000000");
            TimeSpan toNow = new TimeSpan(lTime);
            DateTime dtResult = dtStart.Add(toNow);