C # in week, month, week, week start end time De method summary

1. C # Gets the current time is the week of the year, the week of the month

    private  static int getweeknuminmonth (DateTime daytime)              {                  int dayinmonth = daytime. Day;                  The first day of the month                  DateTime firstday = daytime. AddDays (1-daytime. Day);                  The first day of the month is the week of several                  int weekday = (int) Firstday.dayofweek = = 0? 7: (int) Firstday.dayofweek;                  A few days in the first week of this month                  int firstweekendday = 7-(weekday-1);                  The difference between the current date and the first week                  int diffday = dayinmonth-firstweekendday;                  Diffday = diffday > 0? diffday:1;                  Now is the first week, if divisible by 7 is minus one day                  int weeknuminmonth = ((diffday% 7) = = 0                   ? (DIFFDAY/7-1)                   : (DIFFDAY/7)) + 1 + (Dayinmonth > Firstweekendday? 1:0);                  return weeknuminmonth;              }  

2. Get the week of the year:

    GregorianCalendar gc = new GregorianCalendar ();                 int weekofyear = GC. Getweekofyear (DateTime.Now, Calendarweekrule.firstday, dayofweek.monday);                 Console.WriteLine (weekofyear);                 Console.ReadLine ();  

3, C # Get a few weeks this month and the weeks of the start and end time sample code

 <summary>///received a few weeks this month///</summary>//<param name= "a" ></p                 aram>//<returns></returns> public void NumWeeks (DateTime dt) { years int year = dt.                 year; monthly int month = dt.                 Month;                 The first day of the current month datetime weekstart = new DateTime (year, month, 1); The last day of the month DateTime monend = weekstart.addmonths (1).                 AddDays (-1);                 int i = 1;                 The first day of the current month is the days of the week int dayOfWeek = Convert.ToInt32 (weekStart.DayOfWeek.ToString ("D")); The first week end date of the month datetime weekEnd = DayOfWeek = = 0?                 WeekStart:weekStart.AddDays (7-dayofweek); Richtextbox2.text + = "+ + i +" Week start Date: "+ weekstart.toshortdatestring () +" End Date: "+ weekend.toshortdatestring () +" \ n                 "; When the date is less than or equal to the last day of the month WHile (Weekend.adddays (1) <= monend) {i++;                     The start time of the week Weekstart = weekend.adddays (1); End time of the week weekEnd = weekend.adddays (7) > Monend?                     MonEnd:weekEnd.AddDays (7); Richtextbox2.text + = "+ + i +" Week start Date: "+ weekstart.toshortdatestring () +" End Date: "+ weekend.toshortdatestring () +" \ n                 ";             } Richtextbox2.text + = year + "years" + month + "Monthly Total" + i + "week \ n"; }

4, My97datepicker date plug-in common function description

Http://jingyan.baidu.com/article/e6c8503c7244bae54f1a18c7.html

The above methods are actual use, pro-Test!!!

Summary of recommended

The source of each method is omitted.

C # in week, month, week, week start end time De method summary