Сообщение "Не удалось сгенерировать документ схемы" на странице справки WCF

Question

У меня есть API отдыха (WCF Net 4.0):

[ServiceContract]
interface ISubscriptionService
{
    [OperationContract]
    [WebInvoke(Method = "GET", UriTemplate = Routing.ProductsRoute, BodyStyle = WebMessageBodyStyle.Bare, ResponseFormat = WebMessageFormat.Json)]
    [Description("Получение информации о продуктах")]
    ProductsResult Products(string timestamp, string transaction_id);
}

[ServiceBehavior(AddressFilterMode = AddressFilterMode.Any, InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Single, IncludeExceptionDetailInFaults = true)]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
class SubscriptionService : ISubscriptionService
{
    public ProductsResult Products(string timestamp, string transaction_id)
    {
        SubscriptionProcessing processing = new SubscriptionProcessing();
        processing.SaveHistory(WebOperationContext.Current.IncomingRequest.UriTemplateMatch.RequestUri);
        return processing.GetProducts(timestamp,  transaction_id);
    }
}

Web.config:

<?xml version="1.0"?>
<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0"/>
  </system.web>
  <system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <serviceMetadata httpGetEnabled="false"/>
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="DefaultEndPointBehavior">
          <webHttp helpEnabled="true" />
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <services>
      <service name="CloudWebAPI.SubscriptionService">
        <endpoint address="" kind="webHttpEndpoint" behaviorConfiguration="DefaultEndPointBehavior" contract="CloudWebAPI.ISubscriptionService" />
      </service>
    </services>
  </system.serviceModel>
  <system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Methods" value="GET, POST, OPTIONS, PUT, DELETE"/>
        <add name="Access-Control-Allow-Origin" value="*"/>
        <add name="Access-Control-Allow-Headers" value="Content-Type"/>
      </customHeaders>
    </httpProtocol>
  </system.webServer>
</configuration>

Класс ProductsResult:

[DataContract(Name = "result", Namespace = "")]
public class ProductsResult : CommonResult
{
    public ProductsResult()
    {
        Products = new List<ProductResult>();
    }

    [DataMember(Name = "products", Order = 3)]
    public List<ProductResult> Products { get; set; }
}

Класс CommonResult:

[DataContract(Name = "result", Namespace = "")]
public class CommonResult
{
    public CommonResult()
    {
        TransactionId = string.Empty;
        Error = new ErrorResult();
    }

    [DataMember(Name = "transaction_id", Order = 1)]
    public string TransactionId { get; set; }
    [DataMember(Name = "error", Order = 2)]
    public ErrorResult Error { get; set; }
}

Класс ErrorResult:

[DataContract(Name = "error", Namespace = "")]
public class ErrorResult
{
    public ErrorResult()
    {
        Code = 0;
        Message = string.Empty;
    }

    [DataMember(Name = "error", Order = 1)]
    public int Code { get; set; }
    [DataMember(Name = "message", Order = 2)]
    public string Message { get; set; }
}

Открыв страницу.../rest/SubscriptionService.svc/ помощь / операции / Продукты, я получаю:

Message direction   Format  Body
Request N/A The Request body is empty.
Response    Unknown Could not generate schema document.

Но если вы измените атрибут класса ProductsResult [DataContract (Name = "blabla", Namespace = "")], все будет работать нормально:

Response    Xml Example,Schema
Response    Json    Example
The following is an example response Xml body:
...

Какова причина?

Answer 1

Как говорится в комментарии выше ask125342, классы не могут иметь один и тот же декоратор Name класса, от которого они наследуются - это нарушит автоматическое создание страниц справки WCF.