DateTime.SpecifyKind(DateTime, DateTimeKind) Metoda

Definice

Obor názvů:: System

Sestavení:: mscorlib.dll, System.Runtime.dll

Sestavení:: netstandard.dll, System.Runtime.dll

Sestavení:: System.Runtime.dll

Sestavení:: mscorlib.dll

Sestavení:: netstandard.dll

Zdroj:: DateTime.cs

Zdroj:: DateTime.cs

Zdroj:: DateTime.cs

Zdroj:: DateTime.cs

Zdroj:: DateTime.cs

Důležité

Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.

Vytvoří nový DateTime objekt, který má stejný počet záškrtů jako zadaný DateTime, ale je určen buď jako místní čas, koordinovaný univerzální čas (UTC), nebo ani jeden, jak je uvedeno zadanou DateTimeKind hodnotou.

public:
 static DateTime SpecifyKind(DateTime value, DateTimeKind kind);

public static DateTime SpecifyKind(DateTime value, DateTimeKind kind);

static member SpecifyKind : DateTime * DateTimeKind -> DateTime

Public Shared Function SpecifyKind (value As DateTime, kind As DateTimeKind) As DateTime

Parametry

value: DateTime

Datum a čas.

kind: DateTimeKind

Jedna z hodnot výčtu, která označuje, zda nový objekt představuje místní čas, UTC nebo ani jeden.

Návraty

DateTime

Nový objekt, který má stejný počet záškrtů jako objekt reprezentovaný parametrem value a DateTimeKind hodnotou určenou parametrem kind .

Příklady

Následující příklad používá metodu SpecifyKind k předvedení, jak Kind vlastnost ovlivňuje ToLocalTime a ToUniversalTime konverzní metody.

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

open System

// 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.

let datePatt = @"M/d/yyyy hh:mm:ss tt"

let display title (inputDt: DateTime) =
    // Display the original DateTime.

    let dispDt = inputDt
    let dtString = dispDt.ToString datePatt
    printfn $"%s{title} {dtString}, Kind = {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.

    let dispDt = inputDt.ToLocalTime()
    let dtString = dispDt.ToString datePatt
    printfn $"  ToLocalTime:     {dtString}, Kind = {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.

    let dispDt = inputDt.ToUniversalTime()
    let dtString = dispDt.ToString datePatt
    printfn $"  ToUniversalTime: {dtString}, Kind = {dispDt.Kind}\n" 

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

let displayNow title (inputDt: DateTime) =
    let dtString = inputDt.ToString datePatt
    printfn $"%s{title} {dtString}, Kind = {inputDt.Kind}"

[<EntryPoint>]
let main _ =

    // Get the date and time for the current moment, adjusted
    // to the local time zone.

    let saveNow = DateTime.Now

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

    let saveUtcNow = DateTime.UtcNow

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

    displayNow "UtcNow: .........." saveUtcNow
    displayNow "Now: ............." saveNow
    printfn ""

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

    let myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Utc)
    display "Utc: ............." myDt

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

    let myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Local)
    display "Local: ..........." myDt

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

    let myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Unspecified)
    display "Unspecified: ....." myDt

    0


// 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.

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

'
'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
'

Poznámky

Objekt DateTime se skládá z pole Druh, které označuje, zda je časová hodnota založená na místním čase, koordinovaném univerzálním čase (UTC) nebo ani v poli Ticks, které obsahuje časovou hodnotu měřenou v 100 nanosekundových tickech. Metoda SpecifyKind vytvoří nový DateTime objekt pomocí zadaného kind parametru a původní časové hodnoty.

Důležité

Vrácená DateTime hodnota nepředstavuje stejnou okamžitou dobu jako parametr a SpecifyKind není metodou převodu value časového pásma. Místo toho ponechá čas určený value parametrem beze změny a nastaví Kind vlastnost na kind. Informace o převodech časových pásem naleznete v tématu Převod časů mezi časovými pásmy.

Tato SpecifyKind metoda je užitečná ve scénářích interoperability, kdy obdržíte DateTime objekt s nezadanou polem Kind, ale můžete určit nezávisle na sobě, že pole Ticks představuje místní čas nebo UTC.

Platí pro

Viz také

Interoperabilita modelu COM v aplikacích rozhraní .NET Framework (Visual Basic)

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