Thread.TrySetApartmentState(ApartmentState) Metoda

Definicja

Ustawia stan apartamentu wątku przed jego uruchomieniem.Sets the apartment state of a thread before it is started.

public:
 bool TrySetApartmentState(System::Threading::ApartmentState state);
public bool TrySetApartmentState (System.Threading.ApartmentState state);
member this.TrySetApartmentState : System.Threading.ApartmentState -> bool
Public Function TrySetApartmentState (state As ApartmentState) As Boolean

Parametry

state
ApartmentState

Nowy stan apartamentu.The new apartment state.

Zwraca

true, jeśli jest ustawiony stan apartamentu; w przeciwnym razie false.true if the apartment state is set; otherwise, false.

Wyjątki

Tylko .NET Core: ten element członkowski nie jest obsługiwany na platformach macOS i Linux..NET Core only: This member is not supported on the macOS and Linux platforms.

state nie jest prawidłowym stanem apartamentu.state is not a valid apartment state.

Wątek został uruchomiony i zakończył się lub wywołanie nie jest wykonywane z kontekstu wątku, gdy działa wątek.The thread was started and has terminated, or the call is not being made from the thread's context while the thread is running.

Przykłady

Poniższy przykład kodu demonstruje metody GetApartmentState, SetApartmentStatei TrySetApartmentState.The following code example demonstrates the GetApartmentState, SetApartmentState, and TrySetApartmentState methods. Przykładowy kod tworzy wątek.The code example creates a thread. Przed uruchomieniem wątku GetApartmentState wyświetla początkowy stan ApartmentState.Unknown i SetApartmentState zmienia stan na ApartmentState.STA.Before the thread is started, GetApartmentState displays the initial ApartmentState.Unknown state and SetApartmentState changes the state to ApartmentState.STA. Metoda TrySetApartmentState następnie zwraca false podczas próby zmiany stanu na ApartmentState.MTA, ponieważ stan apartamentu jest już ustawiony.The TrySetApartmentState method then returns false when attempting to change the state to ApartmentState.MTA because the apartment state is already set. Jeśli podjęto próbę wykonania tej samej operacji przy SetApartmentState, InvalidOperationException zostałyby zgłoszone.If the same operation had been attempted with SetApartmentState, InvalidOperationException would have been thrown.

Po rozpoczęciu wątku ponownie zostanie użyta metoda TrySetApartmentState.After the thread is started, the TrySetApartmentState method is used again. Ten czas zgłasza ThreadStateException, ponieważ wątek został już uruchomiony.This time it throws ThreadStateException because the thread has already been started.

using namespace System;
using namespace System::Threading;

void ThreadProc()
{
    Thread::Sleep(2000);
};

void main()
{
    Thread^ t = gcnew Thread(gcnew ThreadStart(ThreadProc));
    Console::WriteLine("Before setting apartment state: {0}", 
            t->GetApartmentState());

    t->SetApartmentState(ApartmentState::STA);
    Console::WriteLine("After setting apartment state: {0}", 
        t->GetApartmentState());

    bool result = t->TrySetApartmentState(ApartmentState::MTA);
    Console::WriteLine("Try to change state: {0}", result);

    t->Start();

    Thread::Sleep(500);

    try
    {
        t->TrySetApartmentState(ApartmentState::STA);
    }
    catch (ThreadStateException^)
    {
        Console::WriteLine("ThreadStateException occurs " +
            "if apartment state is set after starting thread.");
    }

    t->Join();
}

/* This code example produces the following output:

Before setting apartment state: Unknown
After setting apartment state: STA
Try to change state: False
ThreadStateException occurs if apartment state is set after starting thread.
 */
using System;
using System.Threading;

class Example
{
    public static void Main()
    {
        Thread t = new Thread(ThreadProc);
        Console.WriteLine("Before setting apartment state: {0}", 
            t.GetApartmentState());

        t.SetApartmentState(ApartmentState.STA);
        Console.WriteLine("After setting apartment state: {0}", 
            t.GetApartmentState());

        bool result = t.TrySetApartmentState(ApartmentState.MTA);
        Console.WriteLine("Try to change state: {0}", result);

        t.Start();

        Thread.Sleep(500);

        try
        {
            t.TrySetApartmentState(ApartmentState.STA);
        }
        catch (ThreadStateException)
        {
            Console.WriteLine("ThreadStateException occurs " +
                "if apartment state is set after starting thread.");
        }

        t.Join();
    }

    public static void ThreadProc()
    {
        Thread.Sleep(2000);
    }
}

/* This code example produces the following output:

Before setting apartment state: Unknown
After setting apartment state: STA
Try to change state: False
ThreadStateException occurs if apartment state is set after starting thread.
 */
Imports System.Threading

Module Example

    Sub Main()
 
        Dim t As New Thread(AddressOf ThreadProc)
        Console.WriteLine("Before setting apartment state: {0}", _
            t.GetApartmentState())

        t.SetApartmentState(ApartmentState.STA)
        Console.WriteLine("After setting apartment state: {0}", _
            t.GetApartmentState())

        Dim result As Boolean = _
            t.TrySetApartmentState(ApartmentState.MTA)
        Console.WriteLine("Try to change state: {0}", result)

        t.Start()

        Thread.Sleep(500)

        Try
            t.TrySetApartmentState(ApartmentState.STA)
        Catch ex As ThreadStateException
            Console.WriteLine("ThreadStateException occurs " & _
                "if apartment state is set after starting thread.")
        End Try

        t.Join()
    End Sub

    Sub ThreadProc()
        Thread.Sleep(2000)
    End Sub
End Module

' This code example produces the following output:
'
'Before setting apartment state: Unknown
'After setting apartment state: STA
'Try to change state: False
'ThreadStateException occurs if apartment state is set after starting thread.

Uwagi

Nowe wątki są inicjowane jako ApartmentState.MTA, jeśli ich stan apartamentu nie został ustawiony przed rozpoczęciem.New threads are initialized as ApartmentState.MTA if their apartment state has not been set before they are started. Przed uruchomieniem wątku należy ustawić stan apartamentu.Apartment state must be set before a thread is started.

Uwaga

Wątek głównej aplikacji jest domyślnie zainicjowany do ApartmentState.MTA.The main application thread is initialized to ApartmentState.MTA by default. Jedynym sposobem ustawienia stanu apartamentu głównego wątku aplikacji na ApartmentState.STA jest zastosowanie atrybutu STAThreadAttribute do metody punktu wejścia.The only way to set the apartment state of the main application thread to ApartmentState.STA is to apply the STAThreadAttribute attribute to the entry point method.

Metoda TrySetApartmentState, wraz z metodą GetApartmentState i metodą SetApartmentState, zastępuje właściwość ApartmentState.The TrySetApartmentState method, along with the GetApartmentState method and the SetApartmentState method, replaces the ApartmentState property.

Dotyczy