Uzyskiwanie niepoprawnego błędu typu zwracanego podczas próby wywołania usługi WWW WCF 4.0

Próbuję napisać i wywołać serwis WWW WCF, poniżej znajdują się szczegóły:

Web.config:

<add relativeAddress="FetchData.svc" service="WCF.Services.FetchData" />

<service name="WCF.Services.FetchData">
    <endpoint address="" binding="webHttpBinding" bindingConfiguration="" name="FetchData" contract="WCF.Services.FetchData" />
</service>

Klasa FetchData (przykładowy kod):

using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.Web;
using System.Xml;
using Webservices.Services;
using Data = Webservices.Data;
using System.ServiceModel.Web;
using System.IO;
using System.Net;
using System.ServiceModel.Channels;
using System.Web.UI;
using System.Text;


namespace WCF.Services
{    
    [ServiceContract(Namespace = "urn:WCF.Services.FetchData")]
    public class FetchData
    {
        Data.GetConnect mConnect = new Data.GetConnect();
        private Message RetrievePublishedData(String pub, int number)
        {
            String strOutput = String.Empty; 
            if (!String.IsNullOrEmpty(pub))
            {
                Boolean pubURLExists = mConnect.CheckPubUrlExists(pub);

                if (!pubURLExists)
                {
                    WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.NotFound;
                    return WebOperationContext.Current.CreateTextResponse(String.Format("Requested publication '{0}' is not available.", pub), MimeTypes.TextPlain, Encoding.UTF8);
                }
                using (StringWriter sw = new StringWriterEncoding())
                {
                    using (HtmlTextWriter hw = new HtmlTextWriter(sw))
                    {
                        hw.RenderBeginTag(HtmlTextWriterTag.Html);
                        XmlNode publishedData = mConnect.GetPublishedData(pub, number);
                        hw.RenderEndTag();
                    }
                    return WebOperationContext.Current.CreateTextResponse(sw.ToString(),MimeTypes.TextHTML, Encoding.UTF8);
                }
            }
            return WebOperationContext.Current.CreateTextResponse(strOutput, MimeTypes.TextHTML, Encoding.UTF8);
        }
        [OperationContract]
        [WebGet(UriTemplate = "/published/{number}/{*pub=default}")]
        public Message FetchPublished(String pub, int number)
        {
           return RetrievePublishedData(pub, number);
        }
    }
}

Teraz, gdy próbuję przeglądać serwis internetowy, otrzymuję poniżej błąd:

Adres URL usługi sieci Web -http://localhost:8082/FetchData.svc

Błąd: Operacja „FetchPublished” nie mogła zostać załadowana, ponieważ ma parametr lub typ zwracany typu System.ServiceModel.Channels.Message lub typ, który ma MessageContractAttribute i inne parametry różnych typów. Używając System.ServiceModel.Channels.Message lub typy z MessageContractAttribute, metoda nie może używać żadnych innych typów parametrów.

Edytować:

namespace WCFWebServices
{
    [ServiceBehavior(AddressFilterMode = AddressFilterMode.Any)]
     [ServiceContract(Namespace = "urn:WCFWebServices.fetchPush")]
        public class FetchData
        {
         [MessageContract]
         public class RetrievePublishedDataInput
         {
             [MessageBodyMember]
             public String pub;
             [MessageBodyMember]
             public String number;
         }
            private Message RetrievePublishedData(RetrievePublishedDataInput input)
            {
                String strOutput = String.Empty;
                String pub = input.pub;
                String number = input.number;
                if (!String.IsNullOrEmpty(pub))
                {
                    Boolean pubURLExists = true;

                    if (!pubURLExists)
                    {
                        WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.NotFound;
                        return WebOperationContext.Current.CreateTextResponse(String.Format("Requested publication '{0}' is not available.", pub), "application/plain; charset=utf-8", Encoding.UTF8);
                    }
                    using (StringWriter sw = new StringWriter())
                    {
                        using (HtmlTextWriter hw = new HtmlTextWriter(sw))
                        {
                            hw.RenderBeginTag(HtmlTextWriterTag.Html);

                            hw.RenderEndTag();
                        }
                        return WebOperationContext.Current.CreateTextResponse(sw.ToString(), "application/html; charset=utf-8", Encoding.UTF8);
                    }
                }
                return WebOperationContext.Current.CreateTextResponse(strOutput, "application/html; charset=utf-8", Encoding.UTF8);
            }
            [OperationContract]
            [WebGet(UriTemplate = "/publishedData/{number}/{pub=default}")]
            public Message FetchPublished(RetrievePublishedDataInput input)
            {
                return RetrievePublishedData(input);
            }
        }      
}

questionAnswers(1)

yourAnswerToTheQuestion