WCF中的JSON请求和响应

Question

I am trying to make request and receive response from a WCF web service (written in c#) in JSON format. This is the endpoint's configuration:

 <service behaviorConfiguration="UserServiceBehavior" name="UserService">
    <endpoint address="JSON" binding="webHttpBinding" contract="IUserService" 
              behaviorConfiguration="JSONEndpointBehavior" bindingConfiguration="" name="RESTEP">
    </endpoint>
    <endpoint address="" binding="basicHttpBinding" contract="IUserService">
      <identity>
        <dns value="localhost"/>
      </identity>
    </endpoint>
    <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
  </service>

...

<endpointBehaviors>
    <behavior name="JSONEndpointBehavior">
      <webHttp/>
    </behavior>
  </endpointBehaviors>

The annotation on methods is something like this:

[WebInvoke(Method = "GET", UriTemplate = "myUriTemplate", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.Wrapped)]

For methods returning a CLR type it works great: responses are in JSON format (and also requests, I suppose). For methods returning non-CLR types (in my case, a proxy client) if I try to make requests and to receive responses in JSON the server brings me a 404 error, but if I cut off this:

RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json

the server replies with an XML document containing the data I'm searching for. Could this be a problem related to the client proxy? How can I generate e client proxy which supports JSON serialization and de-serialization? If I turn on the help page I can actually see the method in methods list, but I can't fire it from the URL.

Answer 1

Problem found. Thanks to the SvcTracingTool I've discovered that all of that was due to a serialization problem, as the exception raised says:

The InnerException message was 'The type 'xxxxxxxxx' cannot be serialized to JSON because its IsReference setting is 'True'. The JSON format does not support references because there is no standardized format for representing references. To enable serialization, disable the IsReference setting on the type or an appropriate parent class of the type.'. Please see InnerException for more details.

Now, the next step is understand why WCF returned a 404 error instead of the exception.