WCF REST服務模板40和JSON格式的實體框架返回空響應

Question

我試圖用WCF REST服務模板40和實體框架來構建休息JSON服務。

當我試圖創建常規對象，並返回它的一切工作正常，我回來JSON響應（GetEvent方法）

當我試圖返回的對象，從實體框架調用XML格式的一切工作正常（GetEvent3法）

但是當我試圖返回從從實體框架調用對象JSON響應我得到空應答（GetEvent2法）

任何想法，爲什麼？

這是我的代碼：

[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; 
    } 
} 

的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

您是否考慮過使用asp.net mvc作爲您的休息服務？它非常簡單，安全和快捷。這種事情肯定會讓你的生活變得更好。像你在這裏發佈的服務可以在20分鐘內完成，不超過10行代碼。希望能幫助到你。

Answer 2

你失蹤GetEvent2方法[OperationContract]屬性？ 我可以看到，屬性是「示例」部分中提到@http://msdn.microsoft.com/en-us/library/system.servicemodel.web.webgetattribute.responseformat%28v=vs.90%29.aspx

編輯：你GetEvent方法也有應用了[OperationContract]屬性，根據您的描述它的工作原理？