相关疑难解决方法(0)

我搜索了很多并找到了很多解决方案,但没有一个能给我2012-12-31的正确周数.甚至MSDN(链接)上的示例都失败了.

2012-12-31是星期一,因此它应该是第1周,但我尝试的每种方法都给了我53.以下是我尝试过的一些方法:

来自MDSN图书馆:

DateTimeFormatInfo dfi = DateTimeFormatInfo.CurrentInfo;
Calendar cal = dfi.Calendar;

return cal.GetWeekOfYear(date, dfi.CalendarWeekRule, dfi.FirstDayOfWeek);

解决方案2:

return new GregorianCalendar(GregorianCalendarTypes.Localized).GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);

解决方案3:

CultureInfo ciCurr = CultureInfo.CurrentCulture;
int weekNum = ciCurr.Calendar.GetWeekOfYear(dtPassed, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);
return weekNum;

更新

当日期为2012-12-31时,以下方法实际返回1.换句话说,我的问题是我的方法不符合ISO-8601标准.

// This presumes that weeks start with Monday.
// Week 1 is the 1st week of the year with a Thursday in it.
public static int GetIso8601WeekOfYear(DateTime time)
{
    // Seriously cheat.  If its Monday, Tuesday or Wednesday, then it'll 
    // be …

我有以下代码来获取DateTime对象Time中给出的年份的周数

    public static int WeeksInYear(DateTime date)
    {
        GregorianCalendar cal = new GregorianCalendar(GregorianCalendarTypes.Localized);
        return cal.GetWeekOfYear(date, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);
    }

现在我给这个函数的日期是1/1/2012,它应该返回第1周,但是他回到第52周.我似乎无法弄清楚为什么.任何人都知道为什么？

我需要在vb.net中计算当前季度和上一季度的StartDate和EndDate.

在c#中,如何让下一季度的最后一天给出日期？

例如,给定日期是2014-12-02,我需要返回日期2015-03-31.