Question

I had a ASMX service which i migrated to wcf(using basicHttpBinding), now I am using the old client ( whcih uses wsdl.exe to generate the proxy ) to hit the service. I can see that the call reaches the service and the service returns a non null object, however the return value received by the asmx client is null.

Any clues why this might be happening and how to debug this further?

  // This is my webservice 

   [ServiceContract(Namespace = "http://tempuri.org/ManagementWebService")]
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
    public class ManagementService
    {
        [OperationContractAttribute(Action = "http://tempuri.org/ManagementWebService/GetViewSummaryForCurrentUser", ReplyAction = "*")]
        [OperationBehavior(Impersonation = ImpersonationOption.Allowed)]
        [XmlSerializerFormatAttribute()]
        [CLSCompliant(false)]
        [WebMethod]
        public virtual ViewSummaryList GetViewSummaryForCurrentUser()
        {
            return new ViewSummaryList();
        }
}


// This is the client side code which receives a null value.
    [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://tempuri.org/ManagementWebService/GetVi" +
            "ewSummaryForCurrentUser", RequestNamespace="http://tempuri.org/ManagementWebService", ResponseNamespace="http://tempuri.org/ManagementWebService", Use=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]
        [return: System.Xml.Serialization.XmlElementAttribute("Views")]
        public ViewSummaryList GetViewSummaryForCurrentUser() {
            object[] results = this.Invoke("GetViewSummaryForCurrentUser", new object[0]);
            return ((ViewSummaryList)(results[0]));
        }

Answer 1

Figured it out, basically the soap response was incorrectly generating

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><GetViewSummaryForCurrentUserResponse xmlns="http://tempuri.org/ManagementWebService"><GetViewSummaryForCurrentUserResult/></GetViewSummaryForCurrentUserResponse></s:Body></s:Envelope>

instead of

<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><GetViewSummaryForCurrentUserResponse xmlns="http://tempuri.org/ManagementWebService"><Views /></GetViewSummaryForCurrentUserResponse></soap:Body></soap:Envelope>

Notice the difference is an extra GetViewSummaryForCurrentUserResult element instead of Views
in order to fix it I had to add the attribute

        [return: System.ServiceModel.MessageParameterAttribute(Name = "Views")]
public virtual ViewSummaryList GetViewSummaryForCurrentUser()

…. trivial solution really, dont know why i missed i