IAsyncResult IAsyncResult IAsyncResult IAsyncResult Interface

Définition

Représente l'état d'une opération asynchrone.Represents the status of an asynchronous operation.

public interface class IAsyncResult
[System.Runtime.InteropServices.ComVisible(true)]
public interface IAsyncResult
type IAsyncResult = interface
Public Interface IAsyncResult
Dérivé
Attributs

Exemples

L’exemple suivant montre comment utiliser la AsyncWaitHandle propriété pour obtenir un WaitHandleet comment attendre un appel asynchrone sur un délégué.The following example demonstrates how to use the AsyncWaitHandle property to get a WaitHandle, and how to wait for an asynchronous call on a delegate. Le WaitHandle est signalé quand l’appel asynchrone se termine et vous pouvez l’attendre en appelant la méthode WaitOne .The WaitHandle is signaled when the asynchronous call completes, and you can wait for it by calling the WaitOne method.

L’exemple se compose de deux classes: la classe qui contient la méthode qui est appelée de façon asynchrone et la classe qui contient Main la méthode qui effectue l’appel.The example consists of two classes: the class that contains the method that is called asynchronously, and the class that contains the Main method that makes the call.

Pour plus d’informations et pour obtenir d’autres exemples d’appel de méthodes de façon asynchrone à l’aide de délégués, consultez appel de méthodes synchrones de façon asynchrone.For more information and more examples of calling methods asynchronously by using delegates, see Calling Synchronous Methods Asynchronously.

using namespace System;
using namespace System::Threading;
using namespace System::Runtime::InteropServices; 

namespace Examples {
namespace AdvancedProgramming {
namespace AsynchronousOperations
{
    public ref class AsyncDemo 
    {
    public:
        // The method to be executed asynchronously.
        String^ TestMethod(int callDuration, [OutAttribute] int% threadId) 
        {
            Console::WriteLine("Test method begins.");
            Thread::Sleep(callDuration);
            threadId = Thread::CurrentThread->ManagedThreadId;
            return String::Format("My call time was {0}.", callDuration);
        }
    };

    // The delegate must have the same signature as the method
    // it will call asynchronously.
    public delegate String^ AsyncMethodCaller(int callDuration, [OutAttribute] int% threadId);
}}}
using System;
using System.Threading; 

namespace Examples.AdvancedProgramming.AsynchronousOperations
{
    public class AsyncDemo 
    {
        // The method to be executed asynchronously.
        public string TestMethod(int callDuration, out int threadId) 
        {
            Console.WriteLine("Test method begins.");
            Thread.Sleep(callDuration);
            threadId = Thread.CurrentThread.ManagedThreadId;
            return String.Format("My call time was {0}.", callDuration.ToString());
        }
    }
    // The delegate must have the same signature as the method
    // it will call asynchronously.
    public delegate string AsyncMethodCaller(int callDuration, out int threadId);
}
Imports System.Threading
Imports System.Runtime.InteropServices 

Namespace Examples.AdvancedProgramming.AsynchronousOperations
    Public Class AsyncDemo 
        ' The method to be executed asynchronously.
        Public Function TestMethod(ByVal callDuration As Integer, _
                <Out> ByRef threadId As Integer) As String
            Console.WriteLine("Test method begins.")
            Thread.Sleep(callDuration)
            threadId = Thread.CurrentThread.ManagedThreadId()
            return String.Format("My call time was {0}.", callDuration.ToString())
        End Function
    End Class

    ' The delegate must have the same signature as the method
    ' it will call asynchronously.
    Public Delegate Function AsyncMethodCaller(ByVal callDuration As Integer, _
        <Out> ByRef threadId As Integer) As String
End Namespace
#using <TestMethod.dll>

using namespace System;
using namespace System::Threading;
using namespace Examples::AdvancedProgramming::AsynchronousOperations;

void main() 
{
    // The asynchronous method puts the thread id here.
    int threadId;

    // Create an instance of the test class.
    AsyncDemo^ ad = gcnew AsyncDemo();

    // Create the delegate.
    AsyncMethodCaller^ caller = gcnew AsyncMethodCaller(ad, &AsyncDemo::TestMethod);
       
    // Initiate the asychronous call.
    IAsyncResult^ result = caller->BeginInvoke(3000, 
        threadId, nullptr, nullptr);

    Thread::Sleep(0);
    Console::WriteLine("Main thread {0} does some work.",
        Thread::CurrentThread->ManagedThreadId);

    // Wait for the WaitHandle to become signaled.
    result->AsyncWaitHandle->WaitOne();

    // Perform additional processing here.
    // Call EndInvoke to retrieve the results.
    String^ returnValue = caller->EndInvoke(threadId, result);

    // Close the wait handle.
    result->AsyncWaitHandle->Close();

    Console::WriteLine("The call executed on thread {0}, with return value \"{1}\".",
        threadId, returnValue);
}

/* This example produces output similar to the following:

Main thread 1 does some work.
Test method begins.
The call executed on thread 3, with return value "My call time was 3000.".
 */
using System;
using System.Threading;

namespace Examples.AdvancedProgramming.AsynchronousOperations
{
    public class AsyncMain 
    {
        static void Main() 
        {
            // The asynchronous method puts the thread id here.
            int threadId;

            // Create an instance of the test class.
            AsyncDemo ad = new AsyncDemo();

            // Create the delegate.
            AsyncMethodCaller caller = new AsyncMethodCaller(ad.TestMethod);
       
            // Initiate the asychronous call.
            IAsyncResult result = caller.BeginInvoke(3000, 
                out threadId, null, null);

            Thread.Sleep(0);
            Console.WriteLine("Main thread {0} does some work.",
                Thread.CurrentThread.ManagedThreadId);

            // Wait for the WaitHandle to become signaled.
            result.AsyncWaitHandle.WaitOne();

            // Perform additional processing here.
            // Call EndInvoke to retrieve the results.
            string returnValue = caller.EndInvoke(out threadId, result);

            // Close the wait handle.
            result.AsyncWaitHandle.Close();

            Console.WriteLine("The call executed on thread {0}, with return value \"{1}\".",
                threadId, returnValue);
        }
    }
}

/* This example produces output similar to the following:

Main thread 1 does some work.
Test method begins.
The call executed on thread 3, with return value "My call time was 3000.".
 */
Imports System.Threading
Imports System.Runtime.InteropServices 

Namespace Examples.AdvancedProgramming.AsynchronousOperations

    Public Class AsyncMain 
        Shared Sub Main() 
            ' The asynchronous method puts the thread id here.
            Dim threadId As Integer

            ' Create an instance of the test class.
            Dim ad As New AsyncDemo()

            ' Create the delegate.
            Dim caller As New AsyncMethodCaller(AddressOf ad.TestMethod)
       
            ' Initiate the asynchronous call.
            Dim result As IAsyncResult = caller.BeginInvoke(3000, _
                threadId, Nothing, Nothing)

            Thread.Sleep(0)
            Console.WriteLine("Main thread {0} does some work.", _
                Thread.CurrentThread.ManagedThreadId)
            ' Perform additional processing here and then
            ' wait for the WaitHandle to be signaled.
            result.AsyncWaitHandle.WaitOne()

            ' Call EndInvoke to retrieve the results.
            Dim returnValue As String = caller.EndInvoke(threadId, result)

            ' Close the wait handle.
            result.AsyncWaitHandle.Close()

            Console.WriteLine("The call executed on thread {0}, with return value ""{1}"".", _
                threadId, returnValue)
        End Sub
    End Class
End Namespace

'This example produces output similar to the following:
'
'Main thread 1 does some work.
'Test method begins.
'The call executed on thread 3, with return value "My call time was 3000.".

Remarques

L' IAsyncResult interface est implémentée par les classes qui contiennent des méthodes qui peuvent fonctionner de manière asynchrone.The IAsyncResult interface is implemented by classes containing methods that can operate asynchronously. Il s’agit du type de retour des méthodes qui lancent une opération asynchrone FileStream.BeginRead, comme, et elles sont passées aux méthodes qui terminent une opération asynchrone FileStream.EndRead, telle que.It is the return type of methods that initiate an asynchronous operation, such as FileStream.BeginRead, and it is passed to methods that conclude an asynchronous operation, such as FileStream.EndRead. IAsyncResultles objets sont également passés aux méthodes appelées AsyncCallback par les délégués lorsqu’une opération asynchrone se termine.IAsyncResult objects are also passed to methods invoked by AsyncCallback delegates when an asynchronous operation completes.

Un objet qui prend en IAsyncResult charge l’interface stocke les informations d’état d’une opération asynchrone et fournit un objet de synchronisation pour permettre aux threads d’être signalés lorsque l’opération se termine.An object that supports the IAsyncResult interface stores state information for an asynchronous operation and provides a synchronization object to allow threads to be signaled when the operation completes.

Notes

La AsyncResult classe est l’implémentation de IAsyncResult qui est retournée par BeginInvoke la méthode quand vous utilisez un délégué pour appeler une méthode de façon asynchrone.The AsyncResult class is the implementation of IAsyncResult that is returned by the BeginInvoke method when you use a delegate to call a method asynchronously.

Pour obtenir une description détaillée de l' IAsyncResult utilisation de l’interface, consultez la rubrique appel de méthodes synchrones asynchrones .For a detailed description of how the IAsyncResult interface is used, see the Calling Synchronous Methods Asynchronously topic.

Propriétés

AsyncState AsyncState AsyncState AsyncState

Obtient un objet défini par l’utilisateur qui qualifie ou contient des informations sur une opération asynchrone.Gets a user-defined object that qualifies or contains information about an asynchronous operation.

AsyncWaitHandle AsyncWaitHandle AsyncWaitHandle AsyncWaitHandle

Obtient un WaitHandle qui est utilisé pour attendre qu’une opération asynchrone se termine.Gets a WaitHandle that is used to wait for an asynchronous operation to complete.

CompletedSynchronously CompletedSynchronously CompletedSynchronously CompletedSynchronously

Obtient une valeur qui indique si l’opération asynchrone s’est terminée de manière synchrone.Gets a value that indicates whether the asynchronous operation completed synchronously.

IsCompleted IsCompleted IsCompleted IsCompleted

Obtient une valeur qui indique si l'opération asynchrone est terminée.Gets a value that indicates whether the asynchronous operation has completed.

S’applique à