Question

I’m trying to build a Rest JSON service with the WCF REST Service Template 40 and Entity FrameWork.

When I try to create regular object and return it everything works fine and I get back JSON response (GetEvent Method)

When I try to return object that called from entity framework in XML format everything works fine (GetEvent3 Method)

But When i try to return Json response from object that was called from entity framework I get empty response (GetEvent2 Method)

Any idea why?

This is my code:

    [DataContract]
public class Event
{
    [DataMember]
    public int ID { get; set; }

    [DataType(DataType.Text)]
    [Display(Name = "Event Name")]
    [DataMember]
    public string Name { get; set; }

    [Display(Name = "Event StartTime")]
    [DataMember]
    public DateTime StartTime;

    [Display(Name = "Event EndTime")]
    [DataMember]
    public DateTime EndTime;
}




[ServiceContract]
public interface IService1
{
    [OperationContract]
    [WebGet(UriTemplate = "/GetEvent", ResponseFormat = WebMessageFormat.Json)]
    Event GetEvent();

    [WebGet(UriTemplate = "/GetEvent2", ResponseFormat = WebMessageFormat.Json)]
    Event GetEvent2();

    [WebGet(UriTemplate = "/GetEvent3", ResponseFormat = WebMessageFormat.Xml)]
    Event GetEvent3();
}



[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class Service1 : IService1
{
    private readonly EventsDB _db = new EventsDB();

    // This method return good response in Json format
    [WebGet(UriTemplate = "/GetEvent", ResponseFormat = WebMessageFormat.Json)]
    public Event GetEvent()
    {
        return new Event
        {
            ID = 1,
            Name = "A vs. B",
            StartTime = new DateTime(2012, 4, 10, 18, 00, 00),
            EndTime = new DateTime(2012, 4, 11, 18, 00, 00),
        };
    }

    // This method return no response
    [WebGet(UriTemplate = "/GetEvent2", ResponseFormat = WebMessageFormat.Json)]
    public Event GetEvent2()
    {
        Event e = _db.Events.ToList()[0];
        return e;
    }

    // This method return good response in XML format
    [WebGet(UriTemplate = "/GetEvent3", ResponseFormat = WebMessageFormat.Xml)]
    public Event GetEvent3()
    {
        Event e = _db.Events.ToList()[0];
        return e;
    }
}

Web.Config

    <?xml version="1.0" encoding="utf-8"?>
<configuration>

  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.3.1.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
  </configSections>

  <connectionStrings>
    <add name="EventsDB"
         connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=EventsDB"
         providerName="System.Data.SqlClient" />
  </connectionStrings>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
  </system.web>

  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true">
      <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    </modules>
  </system.webServer>

  <system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
    <standardEndpoints>
      <webHttpEndpoint>
        <standardEndpoint name="" helpEnabled="true" automaticFormatSelectionEnabled="false" defaultOutgoingResponseFormat="Json"/>
      </webHttpEndpoint>
    </standardEndpoints>
    <services>
      <service name="WcfRestService3.Service1">
        <endpoint address="http://localhost:50235/service1"
              binding="webHttpBinding"
              contract="WcfRestService3.IService1" />
      </service>
    </services>
  </system.serviceModel>

  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="Data Source=.\SQLEXPRESS; Integrated Security=True; MultipleActiveResultSets=True" />
      </parameters>
    </defaultConnectionFactory>
  </entityFramework>


</configuration>

Answer 1

Have you considered using asp.net mvc for your rest services? It’s really straightforward, safe and quick. It’s the kind of thing that for sure makes your life better. A service like the one you’re posting here can be complete in around 20 minutes with no more than 10 lines of code. hope it helps.