DateTime.ToLocalTime DateTime.ToLocalTime DateTime.ToLocalTime DateTime.ToLocalTime Method

Définition

Convertit la valeur de l'objet DateTime actuel en heure locale.Converts the value of the current DateTime object to local time.

public:
 DateTime ToLocalTime();
public DateTime ToLocalTime ();
member this.ToLocalTime : unit -> DateTime
Public Function ToLocalTime () As DateTime

Retours

Objet dont la propriété Kind est Local et dont la valeur est l'heure locale équivalente à la valeur de l'objet DateTime actif ou MaxValue si la valeur convertie est trop grande pour être représentée par un objet DateTime ou MinValue si la valeur convertie est trop petite pour être représentée comme un objet DateTime.An object whose Kind property is Local, and whose value is the local time equivalent to the value of the current DateTime object, or MaxValue if the converted value is too large to be represented by a DateTime object, or MinValue if the converted value is too small to be represented as a DateTime object.

Exemples

L’exemple suivant illustre la ToLocalTime méthode.The following example demonstrates the ToLocalTime method. Notez que la sortie exacte dépend de la culture actuelle et du fuseau horaire local du système sur lequel elle est exécutée.Note that the exact output depends on the current culture and the local time zone of the system on which it is run.

using namespace System;

void main()
{
   Console::WriteLine("Enter a date and time.");
   String^ strDateTime = Console::ReadLine();

   DateTime localDateTime, univDateTime;
   try
   {
      localDateTime = DateTime::Parse(strDateTime);
      univDateTime = localDateTime.ToUniversalTime();
    
      Console::WriteLine("{0} local time is {1} universal time.",
                         localDateTime, univDateTime );
   }
   catch (FormatException^) 
   {
      Console::WriteLine("Invalid format.");
      return;
   }

   Console::WriteLine("Enter a date and time in universal time.");
   strDateTime = Console::ReadLine();

   try
   {
      univDateTime = DateTime::Parse(strDateTime);
      localDateTime = univDateTime.ToLocalTime();
  
      Console::WriteLine("{0} universal time is {1} local time.",
                         univDateTime, localDateTime );
   }
   catch (FormatException^) 
   {
      Console::WriteLine("Invalid format.");
      return;
   }
}
// The example displays output like the following when run on a 
// computer whose culture is en-US in the Pacific Standard Time zone:
//     Enter a date and time.
//     12/10/2015 6:18 AM
//     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
//     Enter a date and time in universal time.
//     12/20/2015 6:42:00
//     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.
using System;

class Example
{
	static void Main()
	{
		DateTime localDateTime, univDateTime;
		
		Console.WriteLine("Enter a date and time.");
		string strDateTime = Console.ReadLine();

		try {
			localDateTime = DateTime.Parse(strDateTime);
    		univDateTime = localDateTime.ToUniversalTime();
    
    		Console.WriteLine("{0} local time is {1} universal time.",
   								localDateTime,
    								univDateTime); 
		}
		catch (FormatException) {
			Console.WriteLine("Invalid format.");
			return;
		}

		Console.WriteLine("Enter a date and time in universal time.");
		strDateTime = Console.ReadLine();

		try {
			univDateTime = DateTime.Parse(strDateTime);
    		localDateTime = univDateTime.ToLocalTime();
    
    		Console.WriteLine("{0} universal time is {1} local time.",
    								 univDateTime,
    								 localDateTime); 
		}
		catch (FormatException) {
			Console.WriteLine("Invalid format.");
			return;
		}

	}
}
// The example displays output like the following when run on a 
// computer whose culture is en-US in the Pacific Standard Time zone:
//     Enter a date and time.
//     12/10/2015 6:18 AM
//     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
//     Enter a date and time in universal time.
//     12/20/2015 6:42:00
//     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.
Module Example
    Sub Main()
      Dim localDateTime, univDateTime As DateTime
      
      Console.WriteLine("Enter a date and time.")
      Dim strDateTime As String = Console.ReadLine()
      Try
         localDateTime = DateTime.Parse(strDateTime)
         univDateTime = localDateTime.ToUniversalTime()
         Console.WriteLine("{0} local time is {1} universal time.", 
                           localDateTime, univDateTime)
      Catch exp As FormatException
         Console.WriteLine("Invalid format.")
      End Try

      Console.WriteLine("Enter a date and time in universal time.")
      strDateTime = Console.ReadLine()
      Try
         univDateTime = DateTime.Parse(strDateTime)
         localDateTime = univDateTime.ToLocalTime()
  
         Console.WriteLine("{0} universal time is {1} local time.", _
                           univDateTime, localDateTime)
      Catch exp As FormatException
         Console.WriteLine("Invalid format.")
      End Try
    End Sub
End Module
' The example displays output like the following when run on a 
' computer whose culture is en-US in the Pacific Standard Time zone:
'     Enter a date and time.
'     12/10/2015 6:18 AM
'     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
'     Enter a date and time in universal time.
'     12/20/2015 6:42:00
'     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.

L’exemple suivant utilise la SpecifyKind méthode pour illustrer la Kind façon dont la ToLocalTime propriété ToUniversalTime influence les méthodes de conversion et.The following example uses the SpecifyKind method to demonstrate how the Kind property influences the ToLocalTime and ToUniversalTime conversion methods.

// This code example demonstrates the DateTime Kind, Now, and
// UtcNow properties, and the SpecifyKind(), ToLocalTime(), 
// and ToUniversalTime() methods.

using System;

class Sample 
{
    public static void Main() 
    {
// Get the date and time for the current moment, adjusted 
// to the local time zone.

    DateTime saveNow = DateTime.Now;

// Get the date and time for the current moment expressed 
// as coordinated universal time (UTC).

    DateTime saveUtcNow = DateTime.UtcNow;
    DateTime myDt;

// Display the value and Kind property of the current moment 
// expressed as UTC and local time.

    DisplayNow("UtcNow: ..........", saveUtcNow);
    DisplayNow("Now: .............", saveNow);
    Console.WriteLine();

// Change the Kind property of the current moment to 
// DateTimeKind.Utc and display the result.

    myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Utc);
    Display("Utc: .............", myDt);

// Change the Kind property of the current moment to 
// DateTimeKind.Local and display the result.

    myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Local);
    Display("Local: ...........", myDt);

// Change the Kind property of the current moment to 
// DateTimeKind.Unspecified and display the result.

    myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Unspecified);
    Display("Unspecified: .....", myDt);
    }

// Display the value and Kind property of a DateTime structure, the 
// DateTime structure converted to local time, and the DateTime 
// structure converted to universal time. 

    public static string datePatt = @"M/d/yyyy hh:mm:ss tt";
    public static void Display(string title, DateTime inputDt)
    {
    DateTime dispDt = inputDt;
    string dtString;

// Display the original DateTime.

    dtString = dispDt.ToString(datePatt);
    Console.WriteLine("{0} {1}, Kind = {2}", 
                      title, dtString, dispDt.Kind);

// Convert inputDt to local time and display the result. 
// If inputDt.Kind is DateTimeKind.Utc, the conversion is performed.
// If inputDt.Kind is DateTimeKind.Local, the conversion is not performed.
// If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
// performed as if inputDt was universal time.

    dispDt = inputDt.ToLocalTime();
    dtString = dispDt.ToString(datePatt);
    Console.WriteLine("  ToLocalTime:     {0}, Kind = {1}", 
                      dtString, dispDt.Kind);

// Convert inputDt to universal time and display the result. 
// If inputDt.Kind is DateTimeKind.Utc, the conversion is not performed.
// If inputDt.Kind is DateTimeKind.Local, the conversion is performed.
// If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
// performed as if inputDt was local time.

    dispDt = inputDt.ToUniversalTime();
    dtString = dispDt.ToString(datePatt);
    Console.WriteLine("  ToUniversalTime: {0}, Kind = {1}", 
                      dtString, dispDt.Kind);
    Console.WriteLine();
    }

// Display the value and Kind property for DateTime.Now and DateTime.UtcNow.

    public static void DisplayNow(string title, DateTime inputDt)
    {
    string dtString = inputDt.ToString(datePatt);
    Console.WriteLine("{0} {1}, Kind = {2}", 
                      title, dtString, inputDt.Kind);
    }
}

/*
This code example produces the following results:

UtcNow: .......... 5/6/2005 09:34:42 PM, Kind = Utc
Now: ............. 5/6/2005 02:34:42 PM, Kind = Local

Utc: ............. 5/6/2005 02:34:42 PM, Kind = Utc
  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
  ToUniversalTime: 5/6/2005 02:34:42 PM, Kind = Utc

Local: ........... 5/6/2005 02:34:42 PM, Kind = Local
  ToLocalTime:     5/6/2005 02:34:42 PM, Kind = Local
  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc

Unspecified: ..... 5/6/2005 02:34:42 PM, Kind = Unspecified
  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc

*/

' This code example demonstrates the DateTime Kind, Now, and
' UtcNow properties, and the SpecifyKind(), ToLocalTime(), 
' and ToUniversalTime() methods.
Class Sample
    Public Shared Sub Main() 
        ' Get the date and time for the current moment, adjusted 
        ' to the local time zone.
        Dim saveNow As DateTime = DateTime.Now
        
        ' Get the date and time for the current moment expressed 
        ' as coordinated universal time (UTC).
        Dim saveUtcNow As DateTime = DateTime.UtcNow
        Dim myDt As DateTime
        
        ' Display the value and Kind property of the current moment 
        ' expressed as UTC and local time.
        DisplayNow("UtcNow: ..........", saveUtcNow)
        DisplayNow("Now: .............", saveNow)
        Console.WriteLine()
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Utc and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Utc)
        Display("Utc: .............", myDt)
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Local and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Local)
        Display("Local: ...........", myDt)
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Unspecified and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Unspecified)
        Display("Unspecified: .....", myDt)
    End Sub
    
    ' Display the value and Kind property of a DateTime structure, the 
    ' DateTime structure converted to local time, and the DateTime 
    ' structure converted to universal time. 

    Public Shared datePatt As String = "M/d/yyyy hh:mm:ss tt"
    
    Public Shared Sub Display(ByVal title As String, ByVal inputDt As DateTime) 
        Dim dispDt As DateTime = inputDt
        Dim dtString As String
        
        ' Display the original DateTime.
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("{0} {1}, Kind = {2}", title, dtString, dispDt.Kind)
        
        ' Convert inputDt to local time and display the result. 
        ' If inputDt.Kind is DateTimeKind.Utc, the conversion is performed.
        ' If inputDt.Kind is DateTimeKind.Local, the conversion is not performed.
        ' If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
        ' performed as if inputDt was universal time.
        dispDt = inputDt.ToLocalTime()
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("  ToLocalTime:     {0}, Kind = {1}", dtString, dispDt.Kind)
        
        ' Convert inputDt to universal time and display the result. 
        ' If inputDt.Kind is DateTimeKind.Utc, the conversion is not performed.
        ' If inputDt.Kind is DateTimeKind.Local, the conversion is performed.
        ' If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
        ' performed as if inputDt was local time.
        dispDt = inputDt.ToUniversalTime()
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("  ToUniversalTime: {0}, Kind = {1}", dtString, dispDt.Kind)
        Console.WriteLine()
    End Sub
    
    
    ' Display the value and Kind property for DateTime.Now and DateTime.UtcNow.

    Public Shared Sub DisplayNow(ByVal title As String, ByVal inputDt As DateTime) 
        Dim dtString As String = inputDt.ToString(datePatt)
        Console.WriteLine("{0} {1}, Kind = {2}", title, dtString, inputDt.Kind)
    End Sub
End Class 'Sample

'
'This code example produces the following results:
'
'UtcNow: .......... 5/6/2005 09:34:42 PM, Kind = Utc
'Now: ............. 5/6/2005 02:34:42 PM, Kind = Local
'
'Utc: ............. 5/6/2005 02:34:42 PM, Kind = Utc
'  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
'  ToUniversalTime: 5/6/2005 02:34:42 PM, Kind = Utc
'
'Local: ........... 5/6/2005 02:34:42 PM, Kind = Local
'  ToLocalTime:     5/6/2005 02:34:42 PM, Kind = Local
'  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc
'
'Unspecified: ..... 5/6/2005 02:34:42 PM, Kind = Unspecified
'  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
'  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc
'

Remarques

L’heure locale est égale à l’heure UTC (temps universel coordonné) plus l’offset UTC.The local time is equal to the Coordinated Universal Time (UTC) time plus the UTC offset. Pour plus d’informations sur le décalage UTC, TimeZone.GetUtcOffsetconsultez.For more information about the UTC offset, see TimeZone.GetUtcOffset. La conversion prend également en compte la règle d’heure d’été qui s’applique à l’heure représentée par DateTime l’objet actuel.The conversion also takes into account the daylight saving time rule that applies to the time represented by the current DateTime object.

Important

Sur Windows XPWindows XP les systèmes, ToLocalTime la méthode reconnaît uniquement la règle d’ajustement en cours lors de la conversion de l’heure UTC en heure locale.On Windows XPWindows XP systems, the ToLocalTime method recognizes only the current adjustment rule when converting from UTC to local time. Par conséquent, les conversions pour les périodes avant l’apparition de la règle d’ajustement actuelle peuvent ne pas refléter avec précision la différence entre l’heure UTC et l’heure locale.As a result, conversions for periods before the current adjustment rule came into effect may not accurately reflect the difference between UTC and local time.

À partir de la version .NET Framework 2,0, la valeur retournée ToLocalTime par la méthode est déterminée Kind par la propriété de DateTime l’objet actuel.Starting with the .NET Framework version 2.0, the value returned by the ToLocalTime method is determined by the Kind property of the current DateTime object. Le tableau suivant décrit les résultats possibles.The following table describes the possible results.

KindKind RésultatsResults
Utc Cette instance de DateTime est convertie en heure locale.This instance of DateTime is converted to local time.
Local Aucune conversion n’est effectuée.No conversion is performed.
Unspecified Cette instance de DateTime est supposée être une heure UTC, et la conversion est effectuée comme si Kind était Utc.This instance of DateTime is assumed to be a UTC time, and the conversion is performed as if Kind were Utc.

Notes

La ToLocalTime méthode convertit DateTime une valeur UTC en heure locale.The ToLocalTime method converts a DateTime value from UTC to local time. Pour convertir l’heure d’un fuseau horaire désigné en heure locale, utilisez la TimeZoneInfo.ConvertTime méthode.To convert the time in any designated time zone to local time, use the TimeZoneInfo.ConvertTime method.

La valeur retournée par la conversion est DateTime un Kind dont la propriété Localretourne toujours.The value returned by the conversion is a DateTime whose Kind property always returns Local. Par conséquent, un résultat valide est retourné même ToLocalTime si est appliqué de façon répétée DateTimeà la même.Consequently, a valid result is returned even if ToLocalTime is applied repeatedly to the same DateTime.

Notes pour les appelants

Vous pouvez utiliser la ToLocalTime() méthode pour restaurer une valeur de date et d’heure locale qui a été convertie FromFileTimeUtc(Int64) en heure UTC par la ToUniversalTime() méthode ou.You can use the ToLocalTime() method to restore a local date and time value that was converted to UTC by the ToUniversalTime() or FromFileTimeUtc(Int64) method. Toutefois, si l’heure d’origine représente une heure non valide dans le fuseau horaire local, elle ne correspond pas à la valeur restaurée.However, if the original time represents an invalid time in the local time zone, it will not match the restored value. Lorsque la ToLocalTime() méthode convertit une heure UTC en fuseau horaire local, elle ajuste également l’heure pour qu’elle soit valide dans le fuseau horaire local.When the ToLocalTime() method converts a time from UTC to the local time zone, it also adjusts the time so that is valid in the local time zone.

Par exemple, le passage de l’heure d’hiver à l’heure d’été se produit aux États-Unis Heure du Pacifique le 14 mars à 2010, à 2:00 h 00, lorsque l’heure avance d’une heure, à 3:00 du matin.For example, the transition from standard time to daylight saving time occurs in the U.S. Pacific Time zone on March 14, 2010, at 2:00 A.M., when the time advances by one hour, to 3:00 A.M. Cette heure est une heure non valide, autrement dit, un intervalle de temps qui n’existe pas dans ce fuseau horaire.This hour interval is an invalid time, that is, a time interval that does not exist in this time zone. L’exemple suivant montre que lorsqu’une heure qui se trouve dans cette plage est convertie en ToUniversalTime() heure UTC par la méthode et qu' ToLocalTime() elle est ensuite restaurée par la méthode, la valeur d’origine est ajustée pour devenir une heure valide.The following example shows that when a time that falls within this range is converted to UTC by the ToUniversalTime() method and is then restored by the ToLocalTime() method, the original value is adjusted to become a valid time. Vous pouvez déterminer si une valeur de date et d’heure particulière peut être sujette à modification en la passant IsInvalidTime(DateTime) à la méthode, comme l’illustre l’exemple.You can determine whether a particular date and time value may be subject to modification by passing it to the IsInvalidTime(DateTime) method, as the example illustrates.

[!code-csharpSystem.DateTime.ToLocalTime#1] [!code-vbSystem.DateTime.ToLocalTime#1][!code-csharpSystem.DateTime.ToLocalTime#1] [!code-vbSystem.DateTime.ToLocalTime#1]

S’applique à

Voir aussi