IAsyncResult Interfejs

Definicja

Reprezentuje stan operacji asynchronicznej.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
Pochodne
Atrybuty

Przykłady

W poniższym przykładzie pokazano, jak za pomocą właściwości AsyncWaitHandle uzyskać WaitHandlei jak czekać na wywołanie asynchroniczne dla delegata.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 jest sygnalizowane, gdy asynchroniczne wywołanie zakończy się, i można go oczekiwać przez wywołanie metody WaitOne.The WaitHandle is signaled when the asynchronous call completes, and you can wait for it by calling the WaitOne method.

Przykład składa się z dwóch klas: klasy zawierającej metodę, która jest wywoływana asynchronicznie, oraz klasy zawierającej metodę Main, która wywołuje wywołanie.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.

Aby uzyskać więcej informacji i więcej przykładów wywoływania metod asynchronicznie za pomocą delegatów, zobacz Asynchroniczne wywoływanie metod synchronicznych.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.".

Uwagi

Interfejs IAsyncResult jest implementowany przez klasy zawierające metody, które mogą działać asynchronicznie.The IAsyncResult interface is implemented by classes containing methods that can operate asynchronously. Jest to typ zwracany metod, które inicjują operację asynchroniczną, taką jak FileStream.BeginRead, i są przesyłane do metod, które zawierają operację asynchroniczną, taką jak FileStream.EndRead.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. obiekty IAsyncResult są również przesyłane do metod wywoływanych przez AsyncCallback delegatów po zakończeniu operacji asynchronicznej.IAsyncResult objects are also passed to methods invoked by AsyncCallback delegates when an asynchronous operation completes.

Obiekt obsługujący interfejs IAsyncResult przechowuje informacje o stanie dla operacji asynchronicznej i udostępnia obiekt synchronizacji pozwalające na zasygnalizowanie wątków po zakończeniu operacji.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.

Uwaga

Klasa AsyncResult jest implementacją IAsyncResult, która jest zwracana przez metodę BeginInvoke, gdy obiekt delegowany jest używany do wywołania metody asynchronicznie.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.

Szczegółowy opis sposobu używania interfejsu IAsyncResult można znaleźć w temacie wywoływanie metod synchronicznych asynchronicznie .For a detailed description of how the IAsyncResult interface is used, see the Calling Synchronous Methods Asynchronously topic.

Właściwości

AsyncState

Pobiera obiekt zdefiniowany przez użytkownika, który kwalifikuje lub zawiera informacje o operacji asynchronicznej.Gets a user-defined object that qualifies or contains information about an asynchronous operation.

AsyncWaitHandle

Pobiera WaitHandle, który jest używany do oczekiwania na ukończenie operacji asynchronicznej.Gets a WaitHandle that is used to wait for an asynchronous operation to complete.

CompletedSynchronously

Pobiera wartość wskazującą, czy operacja asynchroniczna została zakończona synchronicznie.Gets a value that indicates whether the asynchronous operation completed synchronously.

IsCompleted

Pobiera wartość wskazującą, czy operacja asynchroniczna została ukończona.Gets a value that indicates whether the asynchronous operation has completed.

Dotyczy