Microsoft.CodeDom missing when referencing WCF service who has a callback contract.

Question

if i use a CallbackContract in WCF (.net framework 4.8)

[ServiceContract(CallbackContract = typeof(IEventsService))]

When a service reference in my client app (WPF .Net6.0) the reference.cs file has some lib missing (Microsoft.CodeDom)

I fell like its a bug happen in the tool to generate the client proxy

Anybody had same problem ?

Thanks for your help.

Answer 1

Hi @Bernard Lessard ,
I think you may be missing the System.CodeDom package, if you add it I suggest you try to regenerate the reference.


Best regards,
Lan Huang

---

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

Thanks for the help.. unfortunately now I'm missing : Microsoft.CodeDom.Compiler
And I cannot find it in nugets...

Answer 3

Actually when I have a simple Wcf service it works fine.
But when I have a duplex one, that's when it's not working.
I wanted to have a call back in my apps, but I'll just not use it then..
But its working fine when using .Net Framework 4.8 both client and server.

Answer 4

Hi @Bernard Lessard ,
.NET currently does not support wcf, .NET Foundation provides a client port, you can see the documentation.
https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotnet-5#windows-communication-foundation
About duplex:https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/duplex-services
Best regards,
Lan Huang

---

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 5

// I found a way to fix my problem.. it took me a week of research
// So here it is:
// How to generate WCF Service (.Net Framework 4.8) proxy in client (.Net 6.0):

// If using a callback I need duplex communication
[ServiceContract(CallbackContract = typeof(IEventsService))]
// Just do as explain here but dont expect it to work for Client .Net 6.0 it will only work for client .net Framework 4.8 as Wcf service is .Net Framework 4.8
//https://www.codeproject.com/articles/663333/understanding-events-in-wcf#:~:text=Background%20While%20events%20in%20WCF%20are%20nothing%20more,typical%20relationship%20between%20a%20client%20and%20a%20service.

// so here is what I need to do:
// Use netHttpBinding for duplex
// Put this on web.config of your Wcf service
<service name="HomeManagerWcfService.HomeManagerService" behaviorConfiguration="HomeManagerServiceBehavior">
<host>
<baseAddresses>
<add baseAddress="http://localhost:53318/HomeManagerService"/>
</baseAddresses>
</host>

<endpoint address="" binding="netHttpBinding" contract="HomeManagerWcfService.IHomeManagerService"/>
<!--<endpoint address="" binding="wsDualHttpBinding" contract="HomeManagerWcfService.IHomeManagerService"/>-->
<endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
</service>
</services>

<behaviors>
<serviceBehaviors>
<!-- HomeManagerService Behavior -->
<behavior name="HomeManagerServiceBehavior">
<serviceMetadata httpGetEnabled="true"/>
<serviceDebug includeExceptionDetailInFaults="true "/>
</behavior>
</serviceBehaviors>
</behaviors>

// Generate files for your client proxy on VisualStudio.Tools.Command line.Developer command prompt
svcutil http://localhost:53318/HomeManagerService.svc
//copy both files generated in your client project.
// if using the VS UI generator (Managed connected service) it won't work, there is a bug in it.

// I also need System.ServiceModel.Http
// & I need System.ServiceModel.Duplex
// in the client
// use NetHttpBinding for duplex communication
// Use IHomeManagerServiceCallback to implement the callback function where you want it to run the callback
InstanceContext iCntxt = new InstanceContext(this); // "this" is where i implement the callback for my case
var endpointAddress = new EndpointAddress("http://localhost:53318/HomeManagerService.svc");
var binding = new NetHttpBinding();
var factory = new DuplexChannelFactory<IHomeManagerService>(iCntxt, binding, endpointAddress);
var clientWCF = factory.CreateChannel();

EmailMessage emailMessage = new EmailMessage();
emailMessage.Name = "ww23";
emailMessage.Body = "SSWDDW223";
emailMessage.EmailAddress = "EMAIL AD dsf2223";

clientWCF.SubscribeCalculatedEvent(); // where we register to the event on the server
clientWCF.AddEmail(emailMessage); // the callback event call is in this function on the server