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DateTime.DaysInMonth(Int32, Int32) Metodo

Definizione

Restituisce il numero di giorni del mese specificato dell'anno specificato.

public:
 static int DaysInMonth(int year, int month);
public static int DaysInMonth (int year, int month);
static member DaysInMonth : int * int -> int
Public Shared Function DaysInMonth (year As Integer, month As Integer) As Integer

Parametri

year
Int32

Anno.

month
Int32

Mese (un numero compreso fra 1 e 12).

Restituisce

Int32

Numero di giorni in month per il parametro year specificato.

Se ad esempio month risulta uguale a 2 per febbraio, il valore restituito sarà 28 o 29 a seconda che year sia o meno bisestile.

Eccezioni

month è minore di 1 o maggiore di 12.

-oppure-

year è minore di 1 o maggiore di 9999.

Esempio

L'esempio seguente illustra come usare il metodo per determinare il numero di giorni di luglio DaysInMonth 2001, febbraio 1998 (anno non bisestile) e febbraio 1996 (anno bisestile).

using namespace System;

int main()
{
   const int July = 7;
   const int Feb = 2;
   
   int daysInJuly = System::DateTime::DaysInMonth( 2001, July );
   Console::WriteLine(daysInJuly);   
   // daysInFeb gets 28 because the year 1998 was not a leap year.
   int daysInFeb = System::DateTime::DaysInMonth( 1998, Feb );
   Console::WriteLine(daysInFeb);
   // daysInFebLeap gets 29 because the year 1996 was a leap year.
   int daysInFebLeap = System::DateTime::DaysInMonth( 1996, Feb );
   Console::WriteLine(daysInFebLeap);
}
// The example displays the following output:
//       31
//       28
//       29
using System;

class Example
{
    static void Main()
    {
        const int July = 7;
        const int Feb = 2;

        int daysInJuly = System.DateTime.DaysInMonth(2001, July);
        Console.WriteLine(daysInJuly);

        // daysInFeb gets 28 because the year 1998 was not a leap year.
        int daysInFeb = System.DateTime.DaysInMonth(1998, Feb);
        Console.WriteLine(daysInFeb);

        // daysInFebLeap gets 29 because the year 1996 was a leap year.
        int daysInFebLeap = System.DateTime.DaysInMonth(1996, Feb);
        Console.WriteLine(daysInFebLeap);
    }
}
// The example displays the following output:
//       31
//       28
//       29
Class Example
   Public Shared Sub Main()
      Const July As Integer = 7
      Const Feb As Integer = 2

      Dim daysInJuly As Integer = System.DateTime.DaysInMonth(2001, July)
      Console.WriteLine(daysInJuly)
      
      ' daysInFeb gets 28 because the year 1998 was not a leap year.
      Dim daysInFeb As Integer = System.DateTime.DaysInMonth(1998, Feb)
      Console.WriteLine(daysInFeb)
      ' daysInFebLeap gets 29 because the year 1996 was a leap year.
      Dim daysInFebLeap As Integer = System.DateTime.DaysInMonth(1996, Feb)
      Console.WriteLine(daysInFebLeap)
   End Sub
End Class
' The example displays the following output:
'       31
'       28
'       29

Nell'esempio seguente viene visualizzato il numero di giorni in ogni mese di un anno specificato in una matrice di interi.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      int[] years = { 2012, 2014 };
      DateTimeFormatInfo dtfi = DateTimeFormatInfo.CurrentInfo;
      Console.WriteLine("Days in the Month for the {0} culture " +
                        "using the {1} calendar\n",
                        CultureInfo.CurrentCulture.Name,
                        dtfi.Calendar.GetType().Name.Replace("Calendar", ""));
      Console.WriteLine("{0,-10}{1,-15}{2,4}\n", "Year", "Month", "Days");

      foreach (var year in years) {
         for (int ctr = 0; ctr <= dtfi.MonthNames.Length - 1; ctr++) {
            if (String.IsNullOrEmpty(dtfi.MonthNames[ctr]))
               continue;

            Console.WriteLine("{0,-10}{1,-15}{2,4}", year,
                              dtfi.MonthNames[ctr],
                              DateTime.DaysInMonth(year, ctr + 1));
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//    Days in the Month for the en-US culture using the Gregorian calendar
//
//    Year      Month          Days
//
//    2012      January          31
//    2012      February         29
//    2012      March            31
//    2012      April            30
//    2012      May              31
//    2012      June             30
//    2012      July             31
//    2012      August           31
//    2012      September        30
//    2012      October          31
//    2012      November         30
//    2012      December         31
//
//    2014      January          31
//    2014      February         28
//    2014      March            31
//    2014      April            30
//    2014      May              31
//    2014      June             30
//    2014      July             31
//    2014      August           31
//    2014      September        30
//    2014      October          31
//    2014      November         30
//    2014      December         31
Imports System.Globalization

Module Example
   Public Sub Main()
      Dim years() As Integer = { 2012, 2014 }
      Dim dtfi As DateTimeFormatInfo = DateTimeFormatInfo.CurrentInfo
      Console.WriteLine("Days in the Month for the {0} culture " +
                        "using the {1} calendar", 
                        CultureInfo.CurrentCulture.Name, 
                        dtfi.Calendar.GetType.Name.Replace("Calendar", ""))
      Console.WriteLine()
      Console.WriteLine("{0,-10}{1,-15}{2,4}", "Year", "Month", "Days")
      Console.WriteLine()
      
      For Each [year] As Integer In years
         For ctr As Integer = 0 To dtfi.MonthNames.Length - 1
            If String.IsNullOrEmpty(dtfi.MonthNames(ctr)) Then 
               Continue For
            End If    
            
            Console.WriteLine("{0,-10}{1,-15}{2,4}", [year], 
                              dtfi.MonthNames(ctr), 
                              DateTime.DaysInMonth([year], ctr + 1))
         Next
         Console.WriteLine() 
      Next
   End Sub
End Module
' The example displays the following output:
'    Days in the Month for the en-US culture using the Gregorian calendar
'    
'    Year      Month          Days
'    
'    2012      January          31
'    2012      February         29
'    2012      March            31
'    2012      April            30
'    2012      May              31
'    2012      June             30
'    2012      July             31
'    2012      August           31
'    2012      September        30
'    2012      October          31
'    2012      November         30
'    2012      December         31
'    
'    2014      January          31
'    2014      February         28
'    2014      March            31
'    2014      April            30
'    2014      May              31
'    2014      June             30
'    2014      July             31
'    2014      August           31
'    2014      September        30
'    2014      October          31
'    2014      November         30
'    2014      December         31

Commenti

Il metodo interpreta sempre e come mese e anno del calendario gregoriano anche se il calendario gregoriano non è il calendario corrente DaysInMonth month delle impostazioni cultura year correnti. Per ottenere il numero di giorni in un mese specificato di un determinato calendario, chiamare il metodo del GetDaysInMonth calendario.

Si applica a