请教怎样通过当前日期求得本周开始和结束的日期

Question

也就是求上周日和本周六的日期

Answer 1

获得本周的周六和周日public static void ConvertDateToWeek(DateTime date,out DateTime firstdate,out DateTime lastdate)
{    
            DateTime first=System.DateTime.Now;
            DateTime last=System.DateTime.Now;
            switch (date.DayOfWeek)
            {                
                case System.DayOfWeek.Monday:
                    first=date.AddDays(-1);
                    last=date.AddDays(5);
                    break;
                case System.DayOfWeek.Tuesday:
                    first=date.AddDays(-2);
                    last=date.AddDays(4);
                    break;
                case System.DayOfWeek.Wednesday:
                    first=date.AddDays(-3);
                    last=date.AddDays(3);
                    break;
                case System.DayOfWeek.Thursday:
                    first=date.AddDays(-4);
                    last=date.AddDays(2);
                    break;
                case System.DayOfWeek.Friday:
                    first=date.AddDays(-5);
                    last=date.AddDays(1);
                    break;
                case System.DayOfWeek.Saturday:
                    first=date.AddDays(-6);
                    last=date;
                    break;
                case System.DayOfWeek.Sunday:
                    first=date;
                    last=date.AddDays(6);
                    break;                
            }
            firstdate=first;
            lastdate=last;
}
  //调用
DateTime firstdate;    
DateTime lastdate;
DateTime date=System.DateTime.Now;ConvertDateToWeek(date,out firstdate,out lastdate);略做修改http://singlepine.cnblogs.com/articles/255153.html

Answer 2

DateTime PervSunday =DateTime.Now.AddDays(-(int)DateTime.Now.DayOfWeek);
DateTime CurrSaturday =DateTime.Now.AddDays((6-(int)DateTime.Now.DayOfWeek));

Answer 3

补充一下,西方人和中国人习惯的星期日定义不同,西方人习惯一周第一天是星期天,
中国人习惯最后一天是星期天,  所以代码略作修改.En为西方,Cn为中方
DateTime EnPervSunday =DateTime.Now.AddDays(-7-(int)DateTime.Now.DayOfWeek);
DateTime EnCurrSaturday =DateTime.Now.AddDays(6-(int)DateTime.Now.DayOfWeek);
DateTime CnPervSunday =DateTime.Now.AddDays(-((int)DateTime.Now.DayOfWeek==0?7:(int)DateTime.Now.DayOfWeek));
DateTime CnCurrSaturday =DateTime.Now.AddDays(6-((int)DateTime.Now.DayOfWeek==0?7:(int)DateTime.Now.DayOfWeek));

Answer 4

指定日期所在周的任意一天
SELECT DATEADD(Day,@number-DATEPART(Weekday,@dt),@dt)
指定日期所在周的任意星期几
--A.  星期天做为一周的第1天
SELECT DATEADD(Day,@number-(DATEPART(Weekday,@dt)+@@DATEFIRST-1)%7,@dt)--B.  星期一做为一周的第1天
SELECT DATEADD(Day,@number-(DATEPART(Weekday,@dt)+@@DATEFIRST-2)%7-1,@dt)