How to consume duplex wcf service in Windows Universal App

Question

How can I consume wcf service with duplex contract in Windows universal app?

I'm getting PlatformNotSupportedExcetpion: Operation is not supported on this platform. runtime exception when trying to consume duplex wcf service in Windows Universal App, targeting Windows 10 (10.0; Build 10240)

According msdn it is supported API.

If it is not possible, how should I proceed in my scenario? I have two applications (console and windows universal xaml app) running on the same machine and I need two-way communication.

I have clasic .net 4.6 console app, that create the service host:

var host = new ServiceHost(typeof(MyService), new Uri("net.tcp://localhost:8008/MyService"));

var binding = new NetTcpBinding(); //I've also tried net http binding
binding.Security.Mode = SecurityMode.None;

host.Description.Behaviors.Add(new ServiceMetadataBehavior());
host.AddServiceEndpoint(ServiceMetadataBehavior.MexContractName, 
                        MetadataExchangeBindings.CreateMexTcpBinding(),
                        "mex");  

host.AddServiceEndpoint(typeof(IMyService), binding, "");
host.Open();

service contract:

[ServiceContract(CallbackContract = typeof(IMyServiceCallback))]
public interface IMyService
{
    [OperationContract(IsOneWay = true)]
    void Initialize();
}

public interface IMyServiceCallback
{
    [OperationContract(IsOneWay = true)]
    void OnFrame(int i);
}

I have tried both, ChannelFactory and generated wcf client by Add Service Reference dialog and both NetHttpBinding and NetTcpBinding in the in UWP app.

When I try to create instance of the wcf client, it throws the PlatformNotSupportedExcetpion.

Source: System.Private.ServiceModel

StackTrace:

 at System.ServiceModel.ReflectionExtensions.GetInterfaceMap(Type type, Type interfaceType)
   at System.ServiceModel.Description.TypeLoader.GetIOperationBehaviorAttributesFromType(OperationDescription opDesc, Type targetIface, Type implType)
   at System.ServiceModel.Description.TypeLoader.<>c__DisplayClass8.<AddBehaviorsFromImplementationType>b__10(Type currentType, KeyedByTypeCollection`1 behaviors)
   at System.ServiceModel.Description.TypeLoader.AddBehaviorsAtOneScope[IBehavior,TBehaviorCollection](Type type, TBehaviorCollection descriptionBehaviors, ServiceInheritanceCallback`2 callback)
   at System.ServiceModel.Description.TypeLoader.AddBehaviorsFromImplementationType(ServiceEndpoint serviceEndpoint, Type implementationType)
   at System.ServiceModel.ChannelFactory`1.ReflectOnCallbackInstance(ServiceEndpoint endpoint)
   at System.ServiceModel.ChannelFactory`1.CreateDescription()
   at System.ServiceModel.ChannelFactory.InitializeEndpoint(Binding binding, EndpointAddress address)
   at System.ServiceModel.DuplexChannelFactory`1..ctor(Object callbackObject, Binding binding, EndpointAddress remoteAddress)
   at System.ServiceModel.ClientBase`1..ctor(InstanceContext callbackInstance, Binding binding, EndpointAddress remoteAddress)
   at System.ServiceModel.DuplexClientBase`1..ctor(InstanceContext callbackInstance, Binding binding, EndpointAddress remoteAddress)
   at App1.ServiceReference1.MyServiceClientBase..ctor(InstanceContext callbackInstance)
   at App1.ServiceReference1.MyServiceClient..ctor(MyServiceClientCallback callbackImpl)
   at App1.ServiceReference1.MyServiceClient..ctor()
   at App1.MainPage.<button_Click>d__1.MoveNext()

Answer 1

Stable versions of WCF as part of .NET Core 1.0 was just released last month. Duplex and many other WCF features can now be supported in Windows Universal Apps by referencing the 5.2.2 version of Microsoft.NETCore.UniversalWindowsPlatform package in the project.json file of a UWP project.

Answer 2

Duplex scenario is not supported even in the 10580 build (latest .NETCore v5.1.0).

There was a bug reported ion GitHub about the wrong usage of reflection in WCF duplex implementation. This bug was fixed in the latest build for .net core and you can include the individual package from Nuget gallery. However, this package require you to also include the prerelease versions of System.Runtime and System.Threading.

Hope it helps,