AsyncResult.AsyncState Property

Gets the object provided as the last parameter of a BeginInvoke method call.

Namespace: System.Runtime.Remoting.Messaging
Assembly: mscorlib (in mscorlib.dll)

public virtual Object AsyncState { get; }
/** @property */
public Object get_AsyncState ()

public function get AsyncState () : Object

Property Value

The object provided as the last parameter of a BeginInvoke method call.

For more information about the BeginInvoke method, see Asynchronous Programming Using Delegates.

The following code example demonstrates how the AsyncState property is used to get the last parameter of a BeginInvoke method call. For the complete example code, see the example for the AsyncResult class.

// Asynchronous Callback method.
public static void MyCallback(IAsyncResult ar) {

    // Obtains the last parameter of the delegate call.
    int value = Convert.ToInt32(ar.AsyncState);

    // Obtains return value from the delegate call using EndInvoke.
    AsyncResult aResult = (AsyncResult)ar;
    SampSyncSqrDelegate temp = (SampSyncSqrDelegate)aResult.AsyncDelegate;
    int result = temp.EndInvoke(ar);

    Console.Write("Simple.SomeMethod (AsyncCallback): Result of ");
    Console.WriteLine("{0} in SampleSynchronized.Square is {1} ", value, result);
}

// Asynchronous Callback method.
public static void MyCallback(IAsyncResult ar)
{
    // Obtains the last parameter of the delegate call.
    SampSyncSqrDelegate sampDelg = (SampSyncSqrDelegate)ar.get_AsyncState();
    
    // Obtains return value from the delegate call using EndInvoke.
    AsyncResult aResult = (AsyncResult)ar;
    SampSyncSqrDelegate temp =
        (SampSyncSqrDelegate)(aResult.get_AsyncDelegate());
    int threadId = AppDomain.GetCurrentThreadId();
    int result = temp.EndInvoke(ar);

    Console.Write("Simple.SomeMethod (AsyncCallback): Result of ");
    Console.WriteLine("{0} in SampleSynchronized.Square is {1} ",
        (Int32)value, (Int32)result);
} //MyCallback

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

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