Auto Generated WCF Client Not Able to Direct Call WebHttpBinding Service

I have a WCF service hosted with WebHttpBinding. The service is very simple, an operation contract which accept multiple parameters. My WCF client, auto generated after using the "Add Service Reference", is not able to directly consume the WCF service. The error only occur for WebHttpBinding but not the others.

Here's the story. This is how I decorate my operation contract:

[OperationContract]

[WebInvoke(Method = "POST", UriTemplate = "Submit2String", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.Wrapped)]

string Submit2String(string input1, string input2);

After that, I created a unit test project. And then, add the service reference to my unit test project. Finally, I wrote the following code to call my service.

ExpenseServiceClient proxy = new ExpenseServiceClient();

proxy.Submit2String("test1", "test2");

When I test run my above code, I get the following error:

Error: InvalidOperationException was unhandled by user code
Manual addressing is enabled on this factory, so all messages sent must be pre-addressed.

Here is how my auto generated configuration file look like after using the "Add Service Reference":

<system.serviceModel>

  <bindings>

    <webHttpBinding>

      <binding name="webHttp">

        <security mode="None">

          <transport clientCredentialType="None" />

        </security>

      </binding>

    </webHttpBinding>

  </bindings>

  <client>

    <endpoint binding="webHttpBinding" bindingConfiguration="webHttp"

        contract="ExpenseService.IExpenseService" address="http://localhost:65000/ExpenseService.svc">

    </endpoint>

  </client>

</system.serviceModel>

I realize that only WebHttpBinding has this problem. The solution is simple, just add a behavior configuration as follow:

<behaviors>

  <endpointBehaviors>

    <behavior name="webEndpoint">

      <webHttp defaultBodyStyle="Wrapped" defaultOutgoingResponseFormat="Json" helpEnabled="true"/>

    </behavior>

  </endpointBehaviors>

</behaviors>

Then, update the client endpoint to use the above endpoint behavior.

<client>

  <endpoint binding="webHttpBinding" bindingConfiguration="webHttp" behaviorConfiguration="webEndpoint"

      contract="ExpenseService.IExpenseService" address="http://localhost:65000/ExpenseService.svc">

  </endpoint>

</client>

The problem is solved.