WCF Service Proxy throws exception when more than one parameter is used in [OperationContract] method

Question

I have a WebServiceHost that is being used to host some web services in a console app. I added a service reference to it in my client app and create the proxy like so:

var binding = new WebHttpBinding();
var endPoint = new EndpointAddress(string.Format(Settings.serviceBase, Settings.wcfPort));

ChannelFactory<IzWaveSVC> factory = new ChannelFactory<IzWaveSVC>(new WebHttpBinding(), endPoint);

factory.Endpoint.Behaviors.Add(new WebHttpBehavior());
// **Exception occurs here**
var proxy = (IzWaveSVC)factory.CreateChannel();

It works, but once I added a new method that requires more than one parameter, I started getting this exception when the proxy was created (this was before any communication even took place):

Operation 'setDeviceState' of contract 'IzWaveSVC' specifies multiple request 
body parameters to be serialized without any wrapper elements. At most one 
body parameter can be serialized without wrapper elements. Either remove the 
extra body parameters or set the BodyStyle property on the WebGetAttribute / 
WebInvokeAttribute to Wrapped.

Adding a WebInvokeAttribute and setting the BodyStyle to wrapped has no effect:

[OperationContract]
[WebInvoke(BodyStyle = WebMessageBodyStyle.Wrapped)]        
bool setDeviceState(byte nodeId, bool powered, byte level);

It should be noted that I have other methods that work, but they only have a single parameter so they don't have the above problem.

Just FYI, here's how I setup the host:

endPoint = new EndpointAddress(string.Format(Settings.serviceBase, port));
binding = new WebHttpBinding();

host = new WebServiceHost(singletonObject, new Uri(string.Format(Settings.serviceBase, port)));

host.AddServiceEndpoint(typeof(IzWaveSVC), binding, ""); 
ServiceMetadataBehavior mexBehavior = new ServiceMetadataBehavior();                
mexBehavior.HttpGetEnabled = true;
host.Description.Behaviors.Add(mexBehavior);                
host.AddServiceEndpoint(typeof(IMetadataExchange), MetadataExchangeBindings.CreateMexHttpBinding(), endPoint.Uri.AbsoluteUri + "mex");    
host.Open();            

Any help is appreciated.

Thanks!

Answer 1

It seems you have created Proxy code using Add Service Reference dialog in VS. VS ASR dialog doesn't support WCF REST fully, so, the proxy code is missing [WebInvoke] attribute. Can you try adding [WebInvoke(BodyStyle = WebMessageBodyStyle.Wrapped)] attribute on operations in client proxy?

Answer 2

Two solutions I found:

If you can remove <webHttp/>

From

<behaviors>
  <endpointBehaviors>
    <behavior>
      <!--<webHttp/>-->
    </behavior>
  </endpointBehaviors>
</behaviors>

If you cannot, I had to add the attribute

[WebInvoke(BodyStyle = WebMessageBodyStyle.WrappedRequest)]

Above the Operation Contact Method

Answer 3

Try changing the hosting environment of your service within Visual Studio.
Change it from Use local IIS to 'Use Visual Studio Development Server'.

Apparently there is a different behaviour depending the hosting environment.

Answer 4

updating tha app.config in the client and setting the defaultBodyStyle as WrappedRequest worked for me, where as removing the webHttp cause other issues.

<behaviors>
  <endpointBehaviors>
    <behavior name="webHttp">
      <webHttp defaultBodyStyle="WrappedRequest"/>
    </behavior>
  </endpointBehaviors>