Calendar.GetWeekOfYear(DateTime, CalendarWeekRule, DayOfWeek) Metodo

Definizione

Spazio dei nomi:

System.Globalization

Assembly:

System.Runtime.dll

Origine:

Calendar.cs

Restituisce la settimana dell'anno che comprende la data nel valore DateTime specificato.

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

Parametri

time

DateTime

Valore di data e ora.

rule

CalendarWeekRule

Valore di enumerazione che definisce una settimana di calendario.

firstDayOfWeek

DayOfWeek

Valore di enumerazione che rappresenta il primo giorno della settimana.

Restituisce

Int32

Valore intero positivo che rappresenta la settimana dell'anno che include la data nel parametro time.

Eccezioni

ArgumentOutOfRangeException

time è precedente a MinSupportedDateTime o successivo a MaxSupportedDateTime.

-oppure-

firstDayOfWeek non è un valore valido di DayOfWeek.

-oppure-

rule non è un valore valido di CalendarWeekRule.

Esempio

Nell'esempio di codice seguente viene illustrato il modo in cui il risultato varia a seconda dell'oggetto GetWeekOfYear e dell'oggetto FirstDayOfWeekCalendarWeekRule usato. Se la data specificata è l'ultimo giorno dell'anno, GetWeekOfYear restituisce il numero totale di settimane in tale anno.

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).

Commenti

Questo metodo può essere usato per determinare il numero di settimane nell'anno impostando time sull'ultimo giorno dell'anno.

L'oggetto DateTimeFormatInfo per una determinata cultura che usa il calendario indicato dalla DateTimeFormatInfo.Calendar proprietà include i valori specifici delle impostazioni cultura seguenti che possono essere usati per i rule parametri e firstDayOfWeek :

• La DateTimeFormatInfo.FirstDayOfWeek proprietà contiene il primo giorno predefinito della settimana che può essere usato per il firstDayOfWeek parametro.

• La DateTimeFormatInfo.CalendarWeekRule proprietà contiene la regola della settimana del calendario predefinita che può essere usata per il rule parametro.

Nota

Questo non esegue il mapping esattamente a ISO 8601. Le differenze sono descritte nella voce di blog ISO 8601 Week of Year in Microsoft .NET. A partire da .NET Core 3.0 ISOWeek.GetYear e ISOWeek.GetWeekOfYear risolvere questo problema.

Nell'esempio seguente viene usato l'oggetto cultura corrente per determinare che il 1° gennaio 2011 si trova nella prima settimana dell'anno DateTimeFormatInfo nel calendario gregoriano.

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)

Per alcuni calendari, una chiamata al GetWeekOfYear metodo genera una ArgumentOutOfRangeException combinazione specifica di rule valori e firstDayOfWeek anche se time è maggiore della data restituita dalla proprietà del MinSupportedDateTime calendario. Nella tabella seguente sono elencati i calendari interessati, i valori specifici rule e l'intervallo dei valori più antichi supportati time . Il valore minimo DateTime specifico dipende dal valore del firstDayOfWeek parametro.

Calendario	Valore CalendarWeekRule	Data gregoriana (M/dd/yyyy)	Data nel calendario (M/dd/yyyy)
ChineseLunisolarCalendar	FirstFullWeek	Da 2/19/1901 a 2/25/1901	Da 1/1/1901 a 1/7/1901
ChineseLunisolarCalendar	FirstFourDayWeek	Da 2/19/1901 a 2/22/1901	Da 1/01/1901 a 1/04/1901
HebrewCalendar	FirstDay	9/17/1583	1/01/5344
HebrewCalendar	FirstFullWeek	Da 9/17/1583 a 9/23/1583	1/01/5344 a 1/07/53444
HebrewCalendar	FirstFourDayWeek	Da 9/17/1583 a 9/20/1583	1/01/53444 a 1/04/53444
HijriCalendar	FirstFullWeek	Da 7/18/0622 a 7/24/0622	Da 1/01/0001 a 1/07/0001
HijriCalendar	FirstFourDayWeek	Da 7/18/0622 a 7/21/0622	Da 1/01/0001 a 1/04/0001
JapaneseLunisolarCalendar	FirstFullWeek	Da 1/28/1960 a 2/03/1960	Da 1/01/35 a 1/07/0035
JapaneseLunisolarCalendar	FirstFourDayWeek	Da 1/28/1960 a 1/31/1960	1/01/0035 a 1/04/0035
JulianCalendar	FirstFullWeek	Da 1/01/0001 a 1/05/0001	Da 1/03/0001 a 1/07/0001
JulianCalendar	FirstFourDayWeek	Da 1/01/0001 a 1/02/0001	Da 1/03/0001 a 1/04/0001
KoreanLunisolarCalendar	FirstFullWeek	Da 2/14/0918 a 2/20/0918	1/01/0918 a 1/07/0918
KoreanLunisolarCalendar	FirstFourDayWeek	Da 2/14/0918 a 2/17/0918	Da 1/01/0918 a 1/04/0918
PersianCalendar	FirstFullWeek	Da 3/21/0622 a 3/27/0622	Da 1/01/0001 a 1/07/0001
PersianCalendar	FirstFourDayWeek	Da 3/21/0622 a 3/24/0622	Da 1/01/0001 a 1/04/0001
TaiwanLunisolarCalendar	FirstFullWeek	Da 2/18/1912 a 2/24/1912	Da 1/01/0001 a 1/07/0001
TaiwanLunisolarCalendar	FirstFourDayWeek	Da 2/18/1912 a 2/21/1912	Da 1/01/0001 a 1/04/0001
UmAlQuraCalendar	FirstFullWeek	Da 4/30/1900 a 5/06/1900	Da 1/01/1318 a 1/07/1318
UmAlQuraCalendar	FirstFourDayWeek	Da 4/30/1900 a 5/03/1900	Da 1/01/1318 a 1/04/1318

Vedi anche

• DateTime
• CalendarWeekRule
• DayOfWeek
• GetEra(DateTime)
• GetYear(DateTime)
• GetMonth(DateTime)
• GetDayOfYear(DateTime)
• GetDayOfMonth(DateTime)
• GetDayOfWeek(DateTime)
• GetHour(DateTime)
• GetMinute(DateTime)
• GetSecond(DateTime)
• GetMilliseconds(DateTime)