获取日期范围由周数C＃ [英] Get Date Range by week number c#

问题描述

  

可能重复：
  <一href="http://stackoverflow.com/questions/3854429/in-net-knowing-the-week-number-how-can-i-get-the-weekdays-date">In .NET，知道周数我怎么能得到工作日的日期？

您好，

我要跟你们大家的问题。 我如何获得一个给定的周数的日期范围。

例如： 如果我输入12周输出应该是：

  21-03-2011
22-03-2011
23-03-2011
24-03-2011
25-03-2011
26-03-2011
27-03-2011
 

我真的希望你们能帮助我，我只是不能在任何地方找到awnser！

在此先感谢。

解决方案

  

注意

     

我似乎已经错过了错误。目前的code已被更新为2012-01-30考虑到这个事实，我们现在得出 daysOffset 根据星期二它根据的Mikael史云逊的出现来解决这个问题。

这些ISO8601星期日期计算是有点靠不住的，但是这是你如何做到这一点：

 日期时间jan1 =新的日期时间（YYYY，1，1）;

INT daysOffset = DayOfWeek.Tuesday  -  jan1.DayOfWeek;

日期时间firstMonday = jan1.AddDays（daysOffset）;

VAR CAL = CultureInfo.CurrentCulture.Calendar;

INT firstWeek = cal.GetWeekOfYear（jan1，CalendarWeekRule.FirstFourDayWeek，DayOfWeek.Monday）;

VAR WEEKNUM = WW;

如果（firstWeek＆其中; = 1）
{
    WEEKNUM  -  = 1;
}

VAR的结果= firstMonday.AddDays（WEEKNUM * 7 + D  -  1）;

返回结果;
 

基本上计算出一个基准点，然后加入天，硬的东西，是因为有有53周，有时会发生在一月和第1周，有时可发生在12月的事实。你需要调整的，这是做的一个办法。

以上code计算日期过了一年（年）和周数（WW）和周（D）的日子。

Possible Duplicate:
In .net, knowing the week number how can I get the weekdays date?

Hello,

I've got a question for ya'll. How do i get the date range of a given week number.

For example: If I enter week 12 the output should be:

21-03-2011
22-03-2011
23-03-2011
24-03-2011
25-03-2011
26-03-2011
27-03-2011

I really hope you guys can help me out, i just cant find the awnser anywhere!

Thanks in advance.

解决方案

Note

I appear to have missed bug. The current code have been updated as of 2012-01-30 to account for this fact and we now derive the daysOffset based on Tuesday which according to Mikael Svenson appears to solve the problem.

These ISO8601 week date calculations are a bit wonky, but this is how you do it:

DateTime jan1 = new DateTime(yyyy, 1, 1); 

int daysOffset = DayOfWeek.Tuesday - jan1.DayOfWeek; 

DateTime firstMonday = jan1.AddDays(daysOffset); 

var cal = CultureInfo.CurrentCulture.Calendar; 

int firstWeek = cal.GetWeekOfYear(jan1, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);

var weekNum = ww;

if (firstWeek <= 1) 
{ 
    weekNum -= 1; 
}

var result = firstMonday.AddDays(weekNum * 7 + d - 1);

return result;

Basically calculate a reference point, then add days, the hard stuff has to do with the fact that week 53 can sometimes occur in January and week 1 can sometimes occur in December. You need to adjust for that and this is one way to do that.

The above code calculates the date off a year (yyyy) and week number (ww) and day of week (d).

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