请问如何获取一个时间段内有多少个星期X

Question

   /// <summary>        /// 根据时间段获取每星期X的总数        /// </summary>        /// <param name="beginDateTime">开始时间</param>        /// <param name="endDateTime">结束时间</param>        /// <param name="week">星期几 0:星期日</param>        /// <returns></returns>        public static int GetWeekCount(DateTime beginDateTime, DateTime endDateTime, List<DayOfWeek> weekList)        {        }               如何让这个单元测试相等呀？            List<DayOfWeek> list = new List<DayOfWeek>();            list.Add(DayOfWeek.Tuesday);            list.Add(DayOfWeek.Wednesday);//从2012-5-1日到2012-5-31 日有10天符合星期二或星期三          TestHelper.Test(DateTimeHelper.GetWeekCount(DateTime.Parse("2012-5-1"), DateTime.Parse("2012-5-31"), list) == 10);

Answer 1

public static int GetWeekCount(DateTime begin, DateTime end, List<DayOfWeek> weekList)
{       return Enumerable.Range(0, (end - begin).Days)
           .Count(n => weekList.Contains(begin.AddDays(n).DayOfWeek));
}

Answer 2

获取一段时间内有多少个周几，你这样写试试呢：

       public static int GetWeekCount(DateTime beginDateTime, DateTime endDateTime, List<DayOfWeek> weekList)
       {
           int num = 0;
           for (; beginDateTime < endDateTime; beginDateTime = beginDateTime.AddDays(1))
           {
             foreach ( DayOfWeek dow in weekList)
             {
                 if (beginDateTime.DayOfWeek == dow)
                     num++;
             }
           }
           return num;
       }