Thread.TrySetApartmentState(ApartmentState) Metoda

Definice

Obor názvů:

System.Threading

Sestavení:

netstandard.dll, System.Threading.Thread.dll

Zdroj:

Thread.cs

Nastaví stav bytu vlákna před jeho spuštěním.

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

Nový stav bytu.

Návraty

Boolean

truepokud je stav bytu nastaven; v opačném případě . false

Výjimky

PlatformNotSupportedException

Pouze .NET Core a .NET 5+ : Ve všech případech v systémech macOS a Linux.

ArgumentException

state není platný stav bytu.

ThreadStateException

Vlákno bylo spuštěno a ukončeno, nebo se volání neprovádí z kontextu vlákna, když je vlákno spuštěné.

Příklady

Následující příklad kódu ukazuje GetApartmentState, SetApartmentStatea TrySetApartmentState metody. Příklad kódu vytvoří vlákno. Před spuštěním GetApartmentState vlákna zobrazí počáteční ApartmentState.Unknown stav a SetApartmentState změní stav na ApartmentState.STA. Metoda TrySetApartmentState se pak vrátí false při pokusu o změnu stavu ApartmentState.MTA , protože stav apartmánu je již nastaven. Pokud by došlo k pokusu SetApartmentStateo stejnou operaci, InvalidOperationException byla by vyvolána.

Po spuštění vlákna se TrySetApartmentState metoda znovu použije. Tentokrát se vyvolá ThreadStateException , protože vlákno již bylo spuštěno.

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.
 */

open System.Threading

let threadProc () = Thread.Sleep 2000

let t = Thread threadProc
printfn $"Before setting apartment state: {t.GetApartmentState()}"

t.SetApartmentState ApartmentState.STA
printfn $"After setting apartment state: {t.GetApartmentState()}"

let result = t.TrySetApartmentState ApartmentState.MTA
printfn $"Try to change state: {result}"

t.Start()

Thread.Sleep 500

try
    t.TrySetApartmentState ApartmentState.STA |> ignore
with :? ThreadStateException ->
    printfn "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.

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.

Poznámky

Nová vlákna jsou inicializována, jako ApartmentState.MTA by jejich stav bytu nebyl nastaven před jejich spuštěním. Stav apartmánu musí být nastaven před spuštěním vlákna.

Poznámka:

Hlavní vlákno aplikace se ve výchozím nastavení inicializuje ApartmentState.MTA . Jediným způsobem, jak nastavit stav bytu hlavního vlákna aplikace, ApartmentState.STA je použít STAThreadAttribute atribut na metodu vstupního bodu.

Metoda TrySetApartmentState spolu s metodou GetApartmentState a metodou SetApartmentState nahrazuje ApartmentState vlastnost.