WCF抑制返回__type

Question

對不起，這是一個有點長，但所需要的所有信息，我beleive：

• .NET 4.5，內置在JSON.NET
• 我有以下行爲的定義：

即：

<behaviors> 
    <endpointBehaviors> 
     <behavior name="WebBehavior"> 
      <webHttp helpEnabled="true" automaticFormatSelectionEnabled="true" /> 
     </behavior> 
    </endpointBehaviors> 
    <serviceBehaviors> 
     <behavior name="ServiceBehaviour"> 
      <serviceMetadata httpGetEnabled="true" httpGetBinding="" httpGetBindingConfiguration="" /> 
      <serviceDebug includeExceptionDetailInFaults="true" /> 
     </behavior> 
    </serviceBehaviors> 
</behaviors> 

爲我服務：

[ServiceContract] 
    public interface IWebServiceSrms 
    { 
     //-- Countries -------------------------------------------------------- 
     [OperationContract] 
     [WebInvoke(Method = "GET", BodyStyle = WebMessageBodyStyle.Wrapped, UriTemplate = "/Countries")] 
     [return: MessageParameter(Name = "Countries")] 
     List<Country> Countries(); 

     [OperationContract] 
     [WebInvoke(Method = "GET", BodyStyle = WebMessageBodyStyle.Wrapped, UriTemplate = "/Countries/{aId}")] 
     [return: MessageParameter(Name = "Country")] 
     Country Country(string aId); 
     //-- /Countries ------------------------------------------------------- 
    } 

我已經實現了IErrorHandler然後將下面的錯誤響應以JSON響應返回給客戶端：

[DataContract(IsReference = false)] 
public class ErrorResponse 
{ 
    public ErrorResponse(ErrorTypes aErrorType, ErrorNumber aErrorNumber, string aMessage) 
    { 
     ApiErrorBase = new ApiErrorBase {ErrorNumber = aErrorNumber, ErrorType = aErrorType, Message = aMessage}; 
    } 
    public ErrorResponse(IApiErrorBase aApiErrorBase) 
    { 
     ApiErrorBase = aApiErrorBase as ApiErrorBase; 
    } 
    [DataMember(Name = "ApiError")] 
    public ApiErrorBase ApiErrorBase { get; set; } 

和IApiErrorBase被定義爲：

public interface IApiErrorBase 
{ 
    ErrorNumber ErrorNumber { get; set; } 
    ErrorTypes ErrorType { get; set; } 
    string Message { get; set; } 
} 

和混凝土ApiErrorNase定義爲：

[DataContract(IsReference = false)] 
public class ApiErrorBase : IApiErrorBase 
{ 
    [DataMember(Name = "ErrorType")] 
    private string ErrType 
    { 
     get { return ErrorType.ToString(); } 
     set { return; } 
    } 
    public ApiErrorBase() 
    { 
     ErrorNumber = ErrorNumber.ErrUnknown; 
     ErrorType = ErrorTypes.UnknownError; 
     Message = ""; 
    } 
    [DataMember] 
    public ErrorNumber ErrorNumber { get; set; } 
    [IgnoreDataMember] 
    public ErrorTypes ErrorType { get; set; } 
    [DataMember] 
    public string Message { get; set; } 
} 

然後我有一個助手方法拋出，最終返回錯誤給客戶一個例外：

public static class ErrorHelper 
{ 
    public static void ReturnErrorToClient<T>(ErrorNumber aErrorNumber, ErrorTypes aErrorType, string aMessage, HttpStatusCode aHttpStatusCode = HttpStatusCode.BadRequest) where T : IApiErrorBase, new() 
    { 
     T apiErrorBase = new T {ErrorNumber = aErrorNumber, ErrorType = aErrorType, Message = aMessage}; 

     ErrorResponse errorResponse = new ErrorResponse(apiErrorBase); 

     throw new WebFaultException<ErrorResponse>(errorResponse, aHttpStatusCode); 
    } 
} 

這一切運作良好，並預期，直到我創建了以下ApiErrorAnotherOne子類：

[DataContract(IsReference = false)] 
    [KnownType(typeof(ApiErrorAnotherOne))] 
    public class ApiErrorAnotherOne : ApiErrorBase 
    { 
     [DataMember] 
     public string Homer { get; set; } 

     public ApiErrorAnotherOne() 
     { 
      Homer = "You don't make friends with salad."; 
     } 
    } 

第一個問題是我不得不添加[KnownType（typeof運算（ApiErrorAnotherOne））我收到以下錯誤：

aError = {"Type 'WebService_SRMS.Errors.ApiErrorSomeOtherOne' with data contract name 'ApiErrorSomeOtherOne:http://schemas.datacontract.org/2004/07/WebService_SRMS.Errors' is not expected. Consider using a DataContractResolver or add any types not known statically to the list of kn... 

但是現在我的JSON響應包括如下__type：

{ 
    "ApiError": { 
     "__type": "ApiErrorDono:#WebService_SRMS.Errors", 
     "ErrorNumber": 1, 
     "ErrorType": "UnknownError", 
     "Message": "", 
     "Homer": "You don't make friends with salad." 
    } 
} 

所以我的問題是：

1. 爲什麼在__type出現響應？ （響應的其餘部分是我所想要的）
2. 如何從JSON響應刪除__type？

Answer 1

我認爲這是鏈接你要找的http://blogs.msdn.com/b/carlosfigueira/archive/2011/05/03/wcf-extensibility-message-formatters.aspx

你需要編寫自定義的格式，並且不包括用於處理在它的類型。

Answer 2

你需要指導服務究竟它必須返回。有幾種方法：

• 設置ResponseFormat=WebMessageFormat.Json在你的工作你WebGet屬性合約
• 指定defaultOutgoingResponseFormat="Json"在webhttp設置下的行爲在你的web.config