IAsyncResult IAsyncResult IAsyncResult IAsyncResult Interface

Definición

Representa el estado de una operación asincrónica.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
Derivado
Atributos

Ejemplos

En el ejemplo siguiente se muestra cómo usar AsyncWaitHandle la propiedad para obtener WaitHandleun y cómo esperar una llamada asincrónica en un delegado.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. WaitHandle se señaliza cuando finaliza la llamada asincrónica y puede esperar a que termine llamando al método WaitOne .The WaitHandle is signaled when the asynchronous call completes, and you can wait for it by calling the WaitOne method.

El ejemplo consta de dos clases: la clase que contiene el método al que se llama de forma asincrónica y la clase que Main contiene el método que realiza la llamada.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.

Para obtener más información y ejemplos de cómo llamar a métodos de forma asincrónica mediante delegados, consulte llamar a métodos sincrónicos de forma asincrónica.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.".

Comentarios

La IAsyncResult interfaz la implementan las clases que contienen métodos que pueden funcionar de forma asincrónica.The IAsyncResult interface is implemented by classes containing methods that can operate asynchronously. Es el tipo de valor devuelto de los métodos que inician una operación asincrónica FileStream.BeginRead, como, y se pasan a los métodos que concluyen una operación asincrónica, FileStream.EndReadcomo.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. IAsyncResultlos objetos también se pasan a los métodos invocados por AsyncCallback los delegados cuando se completa una operación asincrónica.IAsyncResult objects are also passed to methods invoked by AsyncCallback delegates when an asynchronous operation completes.

Un objeto que admite la IAsyncResult interfaz almacena información de estado de una operación asincrónica y proporciona un objeto de sincronización para permitir que los subprocesos se señalen cuando se complete la operación.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.

Nota

La AsyncResult clase es la implementación de IAsyncResult que devuelve el BeginInvoke método cuando se usa un delegado para llamar a un método de forma asincrónica.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.

Para obtener una descripción detallada de cómo IAsyncResult se usa la interfaz, vea el tema llamar a métodos sincrónicos de forma asincrónica .For a detailed description of how the IAsyncResult interface is used, see the Calling Synchronous Methods Asynchronously topic.

Propiedades

AsyncState AsyncState AsyncState AsyncState

Obtiene un objeto definido por el usuario que califica o contiene información sobre una operación asincrónica.Gets a user-defined object that qualifies or contains information about an asynchronous operation.

AsyncWaitHandle AsyncWaitHandle AsyncWaitHandle AsyncWaitHandle

Obtiene WaitHandle que se utiliza para esperar a que finalice una operación asincrónica.Gets a WaitHandle that is used to wait for an asynchronous operation to complete.

CompletedSynchronously CompletedSynchronously CompletedSynchronously CompletedSynchronously

Obtiene un valor que indica si se completó la operación asincrónica de forma sincrónica.Gets a value that indicates whether the asynchronous operation completed synchronously.

IsCompleted IsCompleted IsCompleted IsCompleted

Obtiene un valor que indica si se ha completado la operación asincrónica.Gets a value that indicates whether the asynchronous operation has completed.

Se aplica a