Get week of month C# [duplicate]

问题

I want to find a date are now on week number with c# desktop Application.

I've been looking on google, but none that fit my needs.

How do I get a week in a month as the example below?

Example:

I want January 6, 2014 = the first week of January

January 30, 2014 = fourth week of January

but 1 February 2014 = week 4 in January

and 3 February 2014 was the first week in February

回答1:

Here is the method:

static int GetWeekNumberOfMonth(DateTime date)
{
    date = date.Date;
    DateTime firstMonthDay = new DateTime(date.Year, date.Month, 1);
    DateTime firstMonthMonday = firstMonthDay.AddDays((DayOfWeek.Monday + 7 - firstMonthDay.DayOfWeek) % 7);
    if (firstMonthMonday > date)
    {
        firstMonthDay = firstMonthDay.AddMonths(-1);
        firstMonthMonday = firstMonthDay.AddDays((DayOfWeek.Monday + 7 - firstMonthDay.DayOfWeek) % 7);
    }
    return (date - firstMonthMonday).Days / 7 + 1;
}

Test:

Console.WriteLine(GetWeekNumberOfMonth(new DateTime(2014, 1, 6)));  // 1
Console.WriteLine(GetWeekNumberOfMonth(new DateTime(2014, 1, 30))); // 4
Console.WriteLine(GetWeekNumberOfMonth(new DateTime(2014, 2, 1)));  // 4
Console.WriteLine(GetWeekNumberOfMonth(new DateTime(2014, 2, 3)));  // 1

回答2:

  public static int GetWeekNumber(DateTime dt)
  {
          CultureInfo curr= CultureInfo.CurrentCulture;
          int week = curr.Calendar.GetWeekOfYear(dt, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);
          return week;
  }

回答3:

The method will return a structure with the first and last date of that quarter.

 private String test()
    {
        DateRangeStruct retVal;
        retVal.startDate = retVal.endDate = Now;
        retVal = DateRange(DateRangeOptions.Week, DateTime.Today);
    }

please refer these link http://nonsequiturs.com/articles/find-the-first-and-last-day-of-a-date-range-using-c-and-asp-net/

回答4:

I think this is what you want:

public static int GetWeekOfMonth(DateTime date)  
{  
    DateTime beginningOfMonth = new DateTime(date.Year, date.Month, 1);  

    while (date.Date.AddDays(1).DayOfWeek != CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek)  
        date = date.AddDays(1);  

    return (int)Math.Truncate((double)date.Subtract(beginningOfMonth).TotalDays  / 7f) + 1;  
}

Its authored by David M Morton on http://social.msdn.microsoft.com/Forums/vstudio/en-US/bf504bba-85cb-492d-a8f7-4ccabdf882cb/get-week-number-for-month

来源：https://stackoverflow.com/questions/23060121/get-week-of-month-c-sharp

标签

winforms

datetime

week-number