C#函数输入年和周，返回周所在的开始日期和结束日期

Question

    public static string GetWeekRange(int year, int weekIndex)
    {
            if (weekIndex < 1)
            {
                throw new Exception("请输入大于0的整数");
            }
            int allDays = (weekIndex - 1) * 7;
            //确定当年第一天
            DateTime firstDate = new DateTime(year, 1, 1);
            int firstDayOfWeek = (int)firstDate.DayOfWeek;
            firstDayOfWeek = firstDayOfWeek == 0 ? 7 : firstDayOfWeek;            //周开始日
            int startAddDays = allDays + (1 - firstDayOfWeek);
            DateTime weekRangeStart = firstDate.AddDays(startAddDays);
            //周结束日
            int endAddDays = allDays + (7 - firstDayOfWeek);
            DateTime weekRangeEnd = firstDate.AddDays(endAddDays);            if (weekRangeStart.Year > year || (weekRangeStart.Year == year && weekRangeEnd.Year > year))
            {
                throw new Exception("今年没有第" + weekIndex + "周。");
            }                        
    } 这个函数是输入年和周，我想返回weekRangeStart, weekRangeEnd这两个值，如何调用上面这个函数，请指点

Answer 1

参考：http://blog.csdn.net/hefeng_aspnet/article/details/6616650

Answer 2

上面方法没有返回值。。
  //周开始日
  int startAddDays = allDays + (1 - firstDayOfWeek);
  DateTime weekRangeStart = firstDate.AddDays(startAddDays);
  //周结束日
  int endAddDays = allDays + (7 - firstDayOfWeek);
  DateTime weekRangeEnd = firstDate.AddDays(endAddDays);return weekRangeStart.tostring()+" "+weekRangeEnd.tostring();
需要时直接调用这个GetWeekRange(2011,52)就可以了
返回值应该是：2011-12-25 2011-12-31

Answer 3

这是我前几天一个项目里用到时写的。给分吧哥们。我这个很实用哟using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace MEETOK.Components
{
    public class ToolDate
    {        /// <summary>
        /// 周次转化为日期范围
        /// </summary>
        /// <param name="ParmYear">年</param>
        /// <param name="ParmWeek">周次</param>
        /// <returns></returns>
        public static string WeekToDate(int ParmYear, int ParmWeek)
        {            int year = ParmYear, yearStart, yearEnd, monthStart, monthEnd, dayStart, dayEnd, week = ParmWeek, sum = 0;
            int[] days = new int[] { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
            int i;
            sum += 7 * (week - 1);            //修正当前总天数
            #region
            switch (DateTime.Parse(year + "-1-1").DayOfWeek)
            {
                case DayOfWeek.Tuesday:
                    {
                        sum += 5;
                        break;
                    }
                case DayOfWeek.Wednesday:
                    {
                        sum += 4;
                        break;
                    }
                case DayOfWeek.Thursday:
                    {
                        sum += 3;
                        break;
                    }
                case DayOfWeek.Friday:
                    {
                        sum += 2;
                        break;
                    }
                case DayOfWeek.Saturday:
                    {
                        sum += 1;
                        break;
                    }
                case DayOfWeek.Sunday:
                    {
                        //sum;
                        break;
                    }
                default:
                    break;
            }
            #endregion            //判断2月天数
            if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0))
            {
                days[1] = 29;
            }            //计算出当前是一年的第几天
            for (i = 0; i < days.Length; i++)
            {
                if (sum >= days[i])
                {
                    sum -= days[i];
                }
                else
                {
                    break;
                }
            }
            #region
            yearStart = year;
            monthStart = i + 1;
            dayStart = sum + 1;            //修改开始日期
            if (dayStart < 1)
            {
                dayStart += days[11];
                monthStart = 12;
                yearStart--;
            }            yearEnd = yearStart;
            monthEnd = monthStart;
            dayEnd = dayStart + 6;
            if (dayEnd > days[monthStart - 1])
            {
                dayEnd -= days[monthStart - 1];
                monthEnd++;
                if (monthEnd > 12)
                {
                    monthEnd = 1;
                    yearEnd++;
                }
            }
            #endregion
            return yearStart + "." + monthStart + "." + dayStart + "-" + yearEnd + "." + monthEnd + "." + dayEnd;
        }
        /// <summary>
        /// 返回月度范围
        /// </summary>
        /// <param name="ParYear">年</param>
        /// <param name="ParMonth">月</param>
        /// <returns></returns>
        public static string MonthToDate(int ParYear, int ParMonth)
        {
            int[] days = new int[] { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
            //判断2月天数
            if ((ParYear % 400 == 0) || (ParYear % 4 == 0 && ParYear % 100 != 0))
            {
                days[1] = 29;
            }
            return ParYear + "." + ParMonth + ".1-" + ParYear + "." + ParMonth + "." + days[ParMonth - 1];
        }        /// <summary>
        /// 返回季度范围
        /// </summary>
        /// <param name="ParYear"></param>
        /// <param name="Quarter"></param>
        /// <returns></returns>
        public static string QuarterToDate(string ParYear, int Quarter)
        {
            string[] QuarterToMonth = { ParYear + ".01.01-" + ParYear + ".03.31", ParYear + ".04.01-" + ParYear + ".06.30", ParYear + ".07.01-" + ParYear + ".09.30", ParYear + ".10.01-" + ParYear + ".12.31" };
            return QuarterToMonth[Quarter - 1];
        }
        /// <summary>
        /// 返回上下半年范围
        /// </summary>
        /// <param name="ParYear">年</param>
        /// <param name="upOrDown">上/下 半年 0上半年，1下半年</param>
        /// <returns></returns>
        public static string YearToDate(string ParYear, int upOrDown)
        {
            string[] YearStatus = { ParYear + ".01.01-" + ParYear + ".06.30", ParYear + ".07.01-" + ParYear + ".12.31" };
            return YearStatus[upOrDown];
        }    }
}