Task<> does not contain a definition for 'GetAwaiter'

user_713777 0
Viewed 213049

Client

iGame Channel = new ChannelFactory<iGame> ( new BasicHttpBinding ( BasicHttpSecurityMode . None ) , new EndpointAddress ( new Uri ( "http://localhost:58597/Game.svc" ) ) ) . CreateChannel ( );

public Task<SerializableDynamicObject> Client ( SerializableDynamicObject Packet )
{
    return Task<SerializableDynamicObject> . Factory . FromAsync ( Channel . BeginConnection , Channel . EndConnection , Packet , null );
}

Contract

    [OperationContract ( AsyncPattern = true )]
    IAsyncResult BeginConnection ( SerializableDynamicObject Message , AsyncCallback Callback , object State );

    SerializableDynamicObject EndConnection ( IAsyncResult Result );

Service

public IAsyncResult BeginConnection ( SerializableDynamicObject Message , AsyncCallback Callback , object State )
{
    dynamic Request = Message;
    dynamic Response = new SerializableDynamicObject ( );
    if ( Request . Operation = "test" )
    {
        Response . Status = true;
    }
    Response . Status = false;

    return new CompletedAsyncResult<SerializableDynamicObject> ( Response );
}

public SerializableDynamicObject EndConnection ( IAsyncResult Result )
{
    return ( Result as CompletedAsyncResult<SerializableDynamicObject> ) . Data;
}

Exposing Service from Silverlight Client

private async void myButton ( object sender , RoutedEventArgs e )
{
    dynamic Request = new SerializableDynamicObject ( );
    Request . Operation = "test";

    var task = Client ( Request );
    var result = await task;  // <------------------------------ Exception
}

Exception

Task<SerializableDynamicObject > does not contain a definition for 'GetAwaiter'

What's wrong ?

Edit 1 :

Briefly,

Visual studio 2012 RC Silverlight 5 Application consumes Game WCF 4 Service hosted in ASP.net 4 Application with ChannelFactory technique via Shared Portable Library .NET4/SL5 contains the iGame interface with Async CTP

Graph :
ASP.NET <= Class Library ( Game ) <= Portable Library ( iGame ) => Silverlight

Edit 2 :

  • Microsoft.CompilerServices.AsyncTargetingPack.Silverlight5.dll is added in my SL5 Client
  • using System . Threading . Tasks;
async-ctp silverlight-5.0 wcf c#
13 Answers

You could still use framework 4.0 but you have to include getawaiter for the classes:

MethodName(parameters).ConfigureAwait(false).GetAwaiter().GetResult();

user_46027920

The Problem Occur Because the application I was using and the dll i added to my application both have different Versions.

Add this Package- Install-Package Microsoft.Bcl.Async -Version 1.0.168

ADDING THIS PACKAGE async Code becomes Compatible in version 4.0 as well, because Async only work on applications whose Versions are more than or equal to 4.5

user_120140070

Make sure your .NET version 4.5 or greater

user_36315210

In my case just add using System; solve the issue.

user_6320950

I had the same issue, I had to remove the async keyword from the method and also remove the await keyword from the calling method to use getawaiter() without any error.

user_26528750

Another way to reproduce this issue is:

await myvar = myFuncAsync();

Do this instead:

myvar = await myFuncAsync();
user_98220110

If you are writing a Visual Studio Extension (VSIX) then ensure that you have a using statement for Microsoft.VisualStudio.Threading, as such:

using Microsoft.VisualStudio.Threading;
user_13927110
Related