/// <summary>

        /// 计算时间差值

        /// </summary>

        /// <param name="DateTime1"></param>

        /// <param name="DateTime2"></param>

        /// <returns></returns>

        private string DateDiff(DateTime DateTime1, DateTime DateTime2)

        {

            string dateDiff = null;

            TimeSpan ts1 = new TimeSpan(DateTime1.Ticks);

            TimeSpan ts2 = new TimeSpan(DateTime2.Ticks);

            TimeSpan ts = ts1.Subtract(ts2).Duration();

            //dateDiff = ts.Days.ToString() + "天" + ts.Hours.ToString() + "小时" + ts.Minutes.ToString() + "分钟" + ts.Seconds.ToString() + "秒";

            dateDiff = ts.Days.ToString() + "-" + ts.Hours.ToString();

            float nYear = ((float)ts.Days) / ;

            //return nYear.ToString();

            return dateDiff;

        }

调用

 DateTime dt1 = new DateTime();

            DateTime dt2 = new DateTime();

            dt1 = DateTime.Now;

            dt2 = DateTime.Parse("2014-1-2 9:00:00");

            MessageBox.Show(DateDiff(dt1,dt2));