Calendar.GetWeekOfYear(DateTime, CalendarWeekRule, DayOfWeek) Method

Definition

返回一年中包含指定 DateTime 值中的日期的那个星期。Returns the week of the year that includes the date in the specified DateTime value.

public:
 virtual int GetWeekOfYear(DateTime time, System::Globalization::CalendarWeekRule rule, DayOfWeek firstDayOfWeek);
public virtual int GetWeekOfYear (DateTime time, System.Globalization.CalendarWeekRule rule, DayOfWeek firstDayOfWeek);
abstract member GetWeekOfYear : DateTime * System.Globalization.CalendarWeekRule * DayOfWeek -> int
override this.GetWeekOfYear : DateTime * System.Globalization.CalendarWeekRule * DayOfWeek -> int
Public Overridable Function GetWeekOfYear (time As DateTime, rule As CalendarWeekRule, firstDayOfWeek As DayOfWeek) As Integer

Parameters

time
DateTime

日期和时间值。A date and time value.

rule
CalendarWeekRule

定义日历周的枚举值。An enumeration value that defines a calendar week.

firstDayOfWeek
DayOfWeek

表示一周的第一天的枚举值。An enumeration value that represents the first day of the week.

Returns

Int32

一个正整数,用于表示一年中包含 time 参数内日期所在的星期。A positive integer that represents the week of the year that includes the date in the time parameter.

Exceptions

time 早于 MinSupportedDateTime 或晚于 MaxSupportedDateTimetime is earlier than MinSupportedDateTime or later than MaxSupportedDateTime.

- 或 --or- firstDayOfWeek 不是有效的 DayOfWeek 值。firstDayOfWeek is not a valid DayOfWeek value.

- 或 --or- rule 不是有效的 CalendarWeekRule 值。rule is not a valid CalendarWeekRule value.

Examples

下面的代码示例演示 GetWeekOfYear 的结果如何根据所使用的 FirstDayOfWeekCalendarWeekRule 而有所不同。The following code example shows how the result of GetWeekOfYear varies depending on the FirstDayOfWeek and the CalendarWeekRule used. 如果指定的日期是一年中的最后一天,则 GetWeekOfYear 返回该年份中的总周数。If the specified date is the last day of the year, GetWeekOfYear returns the total number of weeks in that year.

using namespace System;
using namespace System::Globalization;
int main()
{
   
   // Gets the Calendar instance associated with a CultureInfo.
   CultureInfo^ myCI = gcnew CultureInfo( "en-US" );
   Calendar^ myCal = myCI->Calendar;
   
   // Gets the DTFI properties required by GetWeekOfYear.
   CalendarWeekRule myCWR = myCI->DateTimeFormat->CalendarWeekRule;
   DayOfWeek myFirstDOW = myCI->DateTimeFormat->FirstDayOfWeek;
   
   // Displays the number of the current week relative to the beginning of the year.
   Console::WriteLine( "The CalendarWeekRule used for the en-US culture is {0}.", myCWR );
   Console::WriteLine( "The FirstDayOfWeek used for the en-US culture is {0}.", myFirstDOW );
   Console::WriteLine( "Therefore, the current week is Week {0} of the current year.", myCal->GetWeekOfYear( DateTime::Now, myCWR, myFirstDOW ) );
   
   // Displays the total number of weeks in the current year.
   DateTime LastDay = System::DateTime( DateTime::Now.Year, 12, 31 );
   Console::WriteLine( "There are {0} weeks in the current year ( {1}).", myCal->GetWeekOfYear( LastDay, myCWR, myFirstDOW ), LastDay.Year );
}

/*
This code produces the following output.  Results vary depending on the system date.

The CalendarWeekRule used for the en-US culture is FirstDay.
The FirstDayOfWeek used for the en-US culture is Sunday.
Therefore, the current week is Week 1 of the current year.
There are 53 weeks in the current year (2001).
*/
using System;
using System.Globalization;

public class SamplesCalendar  {

   public static void Main()  {

      // Gets the Calendar instance associated with a CultureInfo.
      CultureInfo myCI = new CultureInfo("en-US");
      Calendar myCal = myCI.Calendar;

      // Gets the DTFI properties required by GetWeekOfYear.
      CalendarWeekRule myCWR = myCI.DateTimeFormat.CalendarWeekRule;
      DayOfWeek myFirstDOW = myCI.DateTimeFormat.FirstDayOfWeek;

      // Displays the number of the current week relative to the beginning of the year.
      Console.WriteLine( "The CalendarWeekRule used for the en-US culture is {0}.", myCWR );
      Console.WriteLine( "The FirstDayOfWeek used for the en-US culture is {0}.", myFirstDOW );
      Console.WriteLine( "Therefore, the current week is Week {0} of the current year.", myCal.GetWeekOfYear( DateTime.Now, myCWR, myFirstDOW ));

      // Displays the total number of weeks in the current year.
      DateTime LastDay = new System.DateTime( DateTime.Now.Year, 12, 31 );
      Console.WriteLine( "There are {0} weeks in the current year ({1}).", myCal.GetWeekOfYear( LastDay, myCWR, myFirstDOW ), LastDay.Year );
   }
}

/*
This code produces the following output.  Results vary depending on the system date.

The CalendarWeekRule used for the en-US culture is FirstDay.
The FirstDayOfWeek used for the en-US culture is Sunday.
Therefore, the current week is Week 1 of the current year.
There are 53 weeks in the current year (2001).

*/
Imports System.Globalization

Public Class SamplesCalendar

   Public Shared Sub Main()
      
      ' Gets the Calendar instance associated with a CultureInfo.
      Dim myCI As New CultureInfo("en-US")
      Dim myCal As Calendar = myCI.Calendar
      
      ' Gets the DTFI properties required by GetWeekOfYear.
      Dim myCWR As CalendarWeekRule = myCI.DateTimeFormat.CalendarWeekRule
      Dim myFirstDOW As DayOfWeek = myCI.DateTimeFormat.FirstDayOfWeek
      
      ' Displays the number of the current week relative to the beginning of the year.
      Console.WriteLine("The CalendarWeekRule used for the en-US culture is {0}.", myCWR)
      Console.WriteLine("The FirstDayOfWeek used for the en-US culture is {0}.", myFirstDOW)
      Console.WriteLine("Therefore, the current week is Week {0} of the current year.", myCal.GetWeekOfYear(DateTime.Now, myCWR, myFirstDOW))
      
      ' Displays the total number of weeks in the current year.
      Dim LastDay = New System.DateTime(DateTime.Now.Year, 12, 31)
      Console.WriteLine("There are {0} weeks in the current year ({1}).", myCal.GetWeekOfYear(LastDay, myCWR, myFirstDOW), LastDay.Year)
   End Sub
End Class


'This code produces the following output.  Results vary depending on the system date.
'
'The CalendarWeekRule used for the en-US culture is FirstDay.
'The FirstDayOfWeek used for the en-US culture is Sunday.
'Therefore, the current week is Week 1 of the current year.
'There are 53 weeks in the current year (2001).

Remarks

此方法可用于通过将 time 设置为一年中的最后一天来确定一年中的周数。This method can be used to determine the number of weeks in the year by setting time to the last day of the year.

使用 DateTimeFormatInfo.Calendar 属性指示的日历的特定区域性的 DateTimeFormatInfo 对象包括以下特定于区域性的值,这些值可用于 rulefirstDayOfWeek 参数:The DateTimeFormatInfo object for a particular culture that uses the calendar indicated by the DateTimeFormatInfo.Calendar property includes the following culture-specific values that can be used for the rule and firstDayOfWeek parameters:

下面的示例使用当前区域性的 DateTimeFormatInfo 对象来确定2011年1月1日在公历的第一周。The following example uses the current culture's DateTimeFormatInfo object to determine that January 1, 2011 is in the first week of the year in the Gregorian calendar.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      DateTimeFormatInfo dfi = DateTimeFormatInfo.CurrentInfo;
      DateTime date1 = new DateTime(2011, 1, 1);
      Calendar cal = dfi.Calendar;

      Console.WriteLine("{0:d}: Week {1} ({2})", date1,
                        cal.GetWeekOfYear(date1, dfi.CalendarWeekRule,
                                          dfi.FirstDayOfWeek),
                        cal.ToString().Substring(cal.ToString().LastIndexOf(".") + 1));
   }
}
// The example displays the following output:
//       1/1/2011: Week 1 (GregorianCalendar)
Imports System.Globalization

Module Example
   Public Sub Main()
      Dim dfi As DateTimeFormatInfo = DateTimeFormatInfo.CurrentInfo
      Dim date1 As Date = #1/1/2011#
      Dim cal As Calendar = dfi.Calendar
      
      Console.WriteLine("{0:d}: Week {1} ({2})", date1, 
                        cal.GetWeekOfYear(date1, dfi.CalendarWeekRule, 
                                          dfi.FirstDayOfWeek),
                        cal.ToString().Substring(cal.ToString().LastIndexOf(".") + 1))       
   End Sub
End Module
' The example displays the following output:
'       1/1/2011: Week 1 (GregorianCalendar)

对于某些日历,对 GetWeekOfYear 方法的调用将为 rulefirstDayOfWeek 值的特定组合引发 ArgumentOutOfRangeException,即使 time 大于该日历的 MinSupportedDateTime 属性返回的日期。For some calendars, a call to the GetWeekOfYear method throws an ArgumentOutOfRangeException for particular combinations of rule and firstDayOfWeek values even if time is greater than the date returned by that calendar's MinSupportedDateTime property. 下表列出了受影响的日历、特定 rule 值以及支持的最早 time 值的范围。The following table lists the affected calendars, the specific rule values, and the range of the earliest supported time values. 具体的最小 DateTime 值取决于 firstDayOfWeek 参数的值。The specific minimum DateTime value depends on the value of the firstDayOfWeek parameter.

日历Calendar CalendarWeekRule 值CalendarWeekRule value 公历日期(M/dd/yyyy)Gregorian date (M/dd/yyyy) 日历中的日期(M/dd/yyyy)Date in calendar (M/dd/yyyy)
ChineseLunisolarCalendar FirstFullWeek 2/19/1901 至2/25/19012/19/1901 to 2/25/1901 1/1/1901 至1/7/19011/1/1901 to 1/7/1901
ChineseLunisolarCalendar FirstFourDayWeek 2/19/1901 至2/22/19012/19/1901 to 2/22/1901 1/01/1901 至1/04/19011/01/1901 to 1/04/1901
HebrewCalendar FirstDay 9/17/15839/17/1583 1/01/53441/01/5344
HebrewCalendar FirstFullWeek 9/17/1583 至9/23/15839/17/1583 to 9/23/1583 1/01/5344 至1/07/53441/01/5344 to 1/07/5344
HebrewCalendar FirstFourDayWeek 9/17/1583 至9/20/15839/17/1583 to 9/20/1583 1/01/5344 至1/04/53441/01/5344 to 1/04/5344
HijriCalendar FirstFullWeek 7/18/0622 至7/24/06227/18/0622 to 7/24/0622 1/01/0001 至1/07/00011/01/0001 to 1/07/0001
HijriCalendar FirstFourDayWeek 7/18/0622 至7/21/06227/18/0622 to 7/21/0622 1/01/0001 至1/04/00011/01/0001 to 1/04/0001
JapaneseLunisolarCalendar FirstFullWeek 1/28/1960 至2/03/19601/28/1960 to 2/03/1960 1/01/35 至1/07/00351/01/35 to 1/07/0035
JapaneseLunisolarCalendar FirstFourDayWeek 1/28/1960 至1/31/19601/28/1960 to 1/31/1960 1/01/0035 至1/04/00351/01/0035 to 1/04/0035
JulianCalendar FirstFullWeek 1/01/0001 至1/05/00011/01/0001 to 1/05/0001 1/03/0001 至1/07/00011/03/0001 to 1/07/0001
JulianCalendar FirstFourDayWeek 1/01/0001 至1/02/00011/01/0001 to 1/02/0001 1/03/0001 至1/04/00011/03/0001 to 1/04/0001
KoreanLunisolarCalendar FirstFullWeek 2/14/0918 至2/20/09182/14/0918 to 2/20/0918 1/01/0918 至1/07/09181/01/0918 to 1/07/0918
KoreanLunisolarCalendar FirstFourDayWeek 2/14/0918 至2/17/09182/14/0918 to 2/17/0918 1/01/0918 至1/04/09181/01/0918 to 1/04/0918
PersianCalendar FirstFullWeek 3/21/0622 至3/27/06223/21/0622 to 3/27/0622 1/01/0001 至1/07/00011/01/0001 to 1/07/0001
PersianCalendar FirstFourDayWeek 3/21/0622 至3/24/06223/21/0622 to 3/24/0622 1/01/0001 至1/04/00011/01/0001 to 1/04/0001
TaiwanLunisolarCalendar FirstFullWeek 2/18/1912 至2/24/19122/18/1912 to 2/24/1912 1/01/0001 至1/07/00011/01/0001 to 1/07/0001
TaiwanLunisolarCalendar FirstFourDayWeek 2/18/1912 至2/21/19122/18/1912 to 2/21/1912 1/01/0001 至1/04/00011/01/0001 to 1/04/0001
UmAlQuraCalendar FirstFullWeek 4/30/1900 至5/06/19004/30/1900 to 5/06/1900 1/01/1318 至1/07/13181/01/1318 to 1/07/1318
UmAlQuraCalendar FirstFourDayWeek 4/30/1900 至5/03/19004/30/1900 to 5/03/1900 1/01/1318 至1/04/13181/01/1318 to 1/04/1318

Applies to

See also