Calendar.GetWeekOfYear メソッド

指定した DateTime の日付を含むその年の週を返します。

Public Overridable Function GetWeekOfYear( _
   ByVal time As DateTime, _   ByVal rule As CalendarWeekRule, _   ByVal firstDayOfWeek As DayOfWeek _) As Integer
[C#]
public virtual int GetWeekOfYear(DateTimetime,CalendarWeekRulerule,DayOfWeekfirstDayOfWeek);
[C++]
public: virtual int GetWeekOfYear(DateTimetime,CalendarWeekRulerule,DayOfWeekfirstDayOfWeek);
[JScript]
public function GetWeekOfYear(
   time : DateTime,rule : CalendarWeekRule,firstDayOfWeek : DayOfWeek) : int;

パラメータ

• time
  読み取る対象の DateTime 。
• rule
  暦の週を定義する CalendarWeekRule 値。
• firstDayOfWeek
  週の最初の日を表す DayOfWeek 値。

戻り値

time の日付を含む年の週を表す 1 から始まる整数。

例外

例外の種類	条件
ArgumentOutOfRangeException	firstDayOfWeek が暦でサポートされている範囲外の値です。 または rule が有効な CalendarWeekRule 値ではありません。

解説

このメソッドは、その年の最後の日付を time に設定することにより、その年の週の数を確認するために使用できます。

CultureInfo.DateTimeFormat には、 rule と firstDayOfWeek に使用できるカルチャ固有の値が含まれます。

CultureInfo.DateTimeFormat の FirstDayOfWeek には、 CultureInfo.DateTimeFormat の Calendar プロパティで指定された暦を使用して、特定のカルチャにおける週の最初の曜日を表す既定の DayOfWeek 値が格納されます。

CultureInfo.DateTimeFormat の CalendarWeekRule には、 CultureInfo.DateTimeFormat の Calendar プロパティを使用して、特定のカルチャの暦における週を定義する既定の CalendarWeekRule 値が格納されます。

たとえば、 GregorianCalendar では、1 月 1 日の GetWeekOfYear は 1 を返します。

使用例

[Visual Basic, C#, C++] 使用する FirstDayOfWeek と CalendarWeekRule に応じて GetWeekOfYear の結果が変わるようすを示すコードの例を次に示します。指定した日付がその年の最後の日だった場合、 GetWeekOfYear はその年の週の総数を返します。

 
Imports System
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 'Main 
End Class 'SamplesCalendar


'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).


[C#] 
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).

*/

[C++] 
#using <mscorlib.dll>
using namespace System;
using namespace System::Globalization;

int main()
{
   // Gets the Calendar instance associated with a CultureInfo.
   CultureInfo* myCI = new CultureInfo(S"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(S"The CalendarWeekRule used for the en-US culture is {0}.", __box(myCWR));
   Console::WriteLine(S"The FirstDayOfWeek used for the en-US culture is {0}.", __box(myFirstDOW));
   Console::WriteLine(S"Therefore, the current week is Week {0} of the current year.",
      __box(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(S"There are {0} weeks in the current year ( {1}).", 
      __box(myCal -> GetWeekOfYear(LastDay, myCWR, myFirstDOW)), __box(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).
*/

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必要条件

プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET

参照

Calendar クラス | Calendar メンバ | System.Globalization 名前空間 | System.DateTime | CalendarWeekRule | System.DayOfWeek | GetEra | GetYear | GetMonth | GetDayOfYear | GetDayOfMonth | GetDayOfWeek | GetHour | GetMinute | GetSecond | GetMilliseconds