Calendar.GetWeekOfYear(DateTime, CalendarWeekRule, DayOfWeek) 方法

定义

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。

返回

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

time 早于 MinSupportedDateTime 或晚于 MaxSupportedDateTime

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rulefirstDayOfWeek参数的以下特定于区域性的值:

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

另请参阅