public int GetWeekNum(DateTime BeginDate, DateTime EndDate)
        {
            int weekCount = 0;
            //循环计算两个日期之间的周数
            for (DateTime termDate = BeginDate; termDate <= EndDate; termDate = termDate.AddDays(1))
            {
                if (termDate.DayOfWeek == DayOfWeek.Saturday)
                {
                    weekCount++;
                }
            }
            //如果结束日期既不是周六也不是周日，周数要加1
            if (!(EndDate.DayOfWeek == DayOfWeek.Saturday || EndDate.DayOfWeek == DayOfWeek.Sunday))
            {
                weekCount++;
            }
            return weekCount;
        }