C#计算周时间

发布时间：2020-05-14 11:20:14来源：本站阅读（980）

某时间是周几

var w = (int) DateTime.Today.DayOfWeek;

0代表星期日




计算某年某周的起止时间

private Tuple<DateTime, DateTime> GetWeekTime(int year, int week)
        {
            var allDays = (week - 1) * 7;
            var firstDate = new DateTime(year, 1, 1);
            var firstDayOfWeek = (int)firstDate.DayOfWeek;

            firstDayOfWeek = firstDayOfWeek == 0 ? 7 : firstDayOfWeek;
            var startAddDays = allDays + (1 - firstDayOfWeek);
            var endAddDays = allDays + (7 - firstDayOfWeek);
            var result = new Tuple<DateTime, DateTime>(firstDate.AddDays(startAddDays), firstDate.AddDays(endAddDays));
            return result;
        }




计算某个时间是当年第几周

var w = (int)Math.Ceiling((decimal)DateTime.Today.DayOfYear / 7) + 1;