private static int dateDiff(DateTime dtStart, DateTime dtEnd)
        {
            TimeSpan tsStart = new TimeSpan(dtStart.Ticks);
            TimeSpan tsEnd = new TimeSpan(dtEnd.Ticks);
            TimeSpan ts = tsEnd.Subtract(tsStart).Duration();
     520      int dateDiffSecond = ts.Days * 24
 
 * 60 * 60 + ts.Hours * 60 * 60 + ts.Minutes * 60 + ts.Seconds;

            //兩個時間的秒差
            return dateDiffSecond;
        }