Thread.TrySetApartmentState(ApartmentState) Metodo

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

Parametri

Restituisce

true se lo stato dell'appartamento è impostato; in caso contrario, false.

Eccezioni

Esempio

Nell'esempio di codice seguente vengono illustrati i GetApartmentStatemetodi , SetApartmentStatee TrySetApartmentState . L'esempio di codice crea un thread. Prima dell'avvio del thread, GetApartmentState visualizza lo stato iniziale ApartmentState.Unknown e SetApartmentState modifica lo stato in ApartmentState.STA. Il TrySetApartmentState metodo restituisce false quindi quando si tenta di modificare lo stato in ApartmentState.MTA perché lo stato dell'apartment è già impostato. Se la stessa operazione fosse stata tentata con SetApartmentState, InvalidOperationException sarebbe stata generata.

Dopo l'avvio del thread, il TrySetApartmentState metodo viene nuovamente usato. Questa volta viene generata ThreadStateException perché il thread è già stato avviato.

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.

Commenti

I nuovi thread vengono inizializzati come ApartmentState.MTA se lo stato apartment non sia stato impostato prima dell'avvio. Lo stato dell'apartment deve essere impostato prima dell'avvio di un thread.

Il TrySetApartmentState metodo, insieme al GetApartmentState metodo e al SetApartmentState metodo , sostituisce la ApartmentState proprietà .