How to programmatically modify WCF app.config endpoint address setting?

Question

I'd like to programmatically modify my app.config file to set which service file endpoint should be used. What is the best way to do this at runtime? For reference:

<endpoint address="http://mydomain/MyService.svc"
    binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IASRService"
    contract="ASRService.IASRService" name="WSHttpBinding_IASRService">
    <identity>
        <dns value="localhost" />
    </identity>
</endpoint>

Answer 1

Is this on the client side of things??

If so, you need to create an instance of WsHttpBinding, and an EndpointAddress, and then pass those two to the proxy client constructor that takes these two as parameters.

// using System.ServiceModel;
WSHttpBinding binding = new WSHttpBinding();
EndpointAddress endpoint = new EndpointAddress(new Uri("http://localhost:9000/MyService"));

MyServiceClient client = new MyServiceClient(binding, endpoint);

If it's on the server side of things, you'll need to programmatically create your own instance of ServiceHost, and add the appropriate service endpoints to it.

ServiceHost svcHost = new ServiceHost(typeof(MyService), null);

svcHost.AddServiceEndpoint(typeof(IMyService), 
                           new WSHttpBinding(), 
                           "http://localhost:9000/MyService");

Of course you can have multiple of those service endpoints added to your service host. Once you're done, you need to open the service host by calling the .Open() method.

If you want to be able to dynamically - at runtime - pick which configuration to use, you could define multiple configurations, each with a unique name, and then call the appropriate constructor (for your service host, or your proxy client) with the configuration name you wish to use.

E.g. you could easily have:

<endpoint address="http://mydomain/MyService.svc"
        binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IASRService"
        contract="ASRService.IASRService" 
        name="WSHttpBinding_IASRService">
        <identity>
            <dns value="localhost" />
        </identity>
</endpoint>

<endpoint address="https://mydomain/MyService2.svc"
        binding="wsHttpBinding" bindingConfiguration="SecureHttpBinding_IASRService"
        contract="ASRService.IASRService" 
        name="SecureWSHttpBinding_IASRService">
        <identity>
            <dns value="localhost" />
        </identity>
</endpoint>

<endpoint address="net.tcp://mydomain/MyService3.svc"
        binding="netTcpBinding" bindingConfiguration="NetTcpBinding_IASRService"
        contract="ASRService.IASRService" 
        name="NetTcpBinding_IASRService">
        <identity>
            <dns value="localhost" />
        </identity>
</endpoint>

(three different names, different parameters by specifying different bindingConfigurations) and then just pick the right one to instantiate your server (or client proxy).

But in both cases - server and client - you have to pick before actually creating the service host or the proxy client. Once created, these are immutable - you cannot tweak them once they're up and running.

Marc