Calendar.GetWeekOfYear(DateTime, CalendarWeekRule, DayOfWeek) 方法

参考

定义

命名空间:: System.Globalization

程序集:: System.Globalization.dll

程序集:: System.Runtime.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

重要

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返回一年中包含指定 DateTime 值中的日期的那个星期。

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

参数

time: DateTime

日期和时间值。

rule: CalendarWeekRule

定义日历周的枚举值。

firstDayOfWeek: DayOfWeek

表示一周的第一天的枚举值。

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。

例外

ArgumentOutOfRangeException

time 早于 MinSupportedDateTime 或晚于 MaxSupportedDateTime。

或 - firstDayOfWeek 不是有效的 DayOfWeek 值。
或 - rule 不是有效的 CalendarWeekRule 值。

示例

下面的代码示例演示如何 GetWeekOfYear 根据 FirstDayOfWeek 所使用的结果 CalendarWeekRule 而变化。如果指定的日期是年份的最后一天， GetWeekOfYear 则返回该年的总周数。

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).

注解

此方法可用于通过设置为 time 年份的最后一天来确定年份中的周数。

DateTimeFormatInfo使用属性指示DateTimeFormatInfo.Calendar的日历的特定区域性的对象包括可用于rule和firstDayOfWeek参数的以下特定于区域性的值：

该 DateTimeFormatInfo.FirstDayOfWeek 属性包含可用于 firstDayOfWeek 参数的每周的默认第一天。
该 DateTimeFormatInfo.CalendarWeekRule 属性包含可用于 rule 参数的默认日历周规则。

备注

这不会完全映射到 ISO 8601。 Microsoft .NET 中的博客文章 ISO 8601 Year 周格式讨论了这些差异。从 .NET Core 3.0 开始， ISOWeek.GetYear 解决此问题 ISOWeek.GetWeekOfYear 。

以下示例使用当前区域性 DateTimeFormatInfo 的对象来确定 2011 年 1 月 1 日在公历的第一周。

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，对方法的调用会引发特定组合和值的调用GetWeekOfYear，即使time大于该日历属性返回的MinSupportedDateTime日期。firstDayOfWeek rule ArgumentOutOfRangeException 下表列出了受影响的日历、特定 rule 值以及最早支持 time 的值的范围。特定的最小值 DateTime 取决于参数的值 firstDayOfWeek 。

日历	CalendarWeekRule 值	公历日期 (M/dd/yyyy)	日历中的日期 (M/dd/yyyy)
ChineseLunisolarCalendar	FirstFullWeek	2/19/1901 至 2/25/1901	1/1/1901 到 1/7/1901
ChineseLunisolarCalendar	FirstFourDayWeek	2/19/1901 至 2/22/1901	1/01/1901 至 1/04/1901
HebrewCalendar	FirstDay	9/17/1583	1/01/5344
HebrewCalendar	FirstFullWeek	9/17/1583 到 9/23/1583	1/01/5344 到 1/07/5344
HebrewCalendar	FirstFourDayWeek	9/17/1583 到 9/20/1583	1/01/5344 到 1/04/5344
HijriCalendar	FirstFullWeek	7/18/0622 到 7/24/0622	1/01/0001 至 1/07/0001
HijriCalendar	FirstFourDayWeek	7/18/0622 到 7/21/0622	1/01/0001 到 1/04/0001
JapaneseLunisolarCalendar	FirstFullWeek	1/28/1960 至 2/03/1960	1/01/35 至 1/07/0035
JapaneseLunisolarCalendar	FirstFourDayWeek	1/28/1960 至 1/31/1960	1/01/0035 至 1/04/0035
JulianCalendar	FirstFullWeek	1/01/0001 到 1/05/0001	1/03/0001 到 1/07/0001
JulianCalendar	FirstFourDayWeek	1/01/0001 至 1/02/0001	1/03/0001 到 1/04/0001
KoreanLunisolarCalendar	FirstFullWeek	2/14/0918 至 2/20/0918	1/01/0918 至 1/07/0918
KoreanLunisolarCalendar	FirstFourDayWeek	2/14/0918 至 2/17/0918	1/01/0918 至 1/04/0918
PersianCalendar	FirstFullWeek	3/21/0622 到 3/27/0622	1/01/0001 至 1/07/0001
PersianCalendar	FirstFourDayWeek	3/21/0622 到 3/24/0622	1/01/0001 到 1/04/0001
TaiwanLunisolarCalendar	FirstFullWeek	2/18/1912 至 2/24/1912	1/01/0001 至 1/07/0001
TaiwanLunisolarCalendar	FirstFourDayWeek	2/18/1912 至 2/21/1912	1/01/0001 到 1/04/0001
UmAlQuraCalendar	FirstFullWeek	4/30/1900 到 5/06/1900	1/01/1318 至 1/07/1318
UmAlQuraCalendar	FirstFourDayWeek	4/30/1900 至 5/03/1900	1/01/1318 至 1/04/1318

适用于

Calendar.GetWeekOfYear(DateTime, CalendarWeekRule, DayOfWeek) 方法

定义

参数

返回

例外

示例

注解

适用于

另请参阅