/**//// <summary>

        /// 得到一年中的某周的起始日和截止日

        /// 年 nYear

        /// 周数 nNumWeek

        /// 周始 out dtWeekStart

        /// 周终 out dtWeekeEnd

        /// </summary>

        /// <param name="nYear"></param>

        /// <param name="nNumWeek"></param>

        /// <param name="dtWeekStart"></param>

        /// <param name="dtWeekeEnd"></param>

        public static void GetWeek(int nYear, int nNumWeek, out   DateTime dtWeekStart, out   DateTime dtWeekeEnd)

        {

            DateTime dt = new DateTime(nYear, 1, 1);

            dt = dt + new TimeSpan((nNumWeek - 1) * 7, 0, 0, 0);

            dtWeekStart = dt.AddDays(-(int)dt.DayOfWeek + (int)DayOfWeek.Monday);

            dtWeekeEnd = dt.AddDays((int)DayOfWeek.Saturday - (int)dt.DayOfWeek + 1);

        }





 /**//// <summary>

        /// 求当前日期是一年的中第几周

        /// </summary>

        /// <param name="date"></param>

        /// <returns></returns>

        public static int WeekOfYear(DateTime curDay)

        {

            int firstdayofweek = Convert.ToInt32(Convert.ToDateTime(curDay.Year.ToString() + "- " + "1-1 ").DayOfWeek);



            int days = curDay.DayOfYear;

            int daysOutOneWeek = days - (7 - firstdayofweek);