返回 304 Not Modified with ServiceStack 时防止不需要的标头

Question

使用 ServiceStack，我只想返回 304 Not Modified：

HTTP/1.1 304 Not Modified

但是 ServiceStack 添加了许多其他不需要的（返回带有 304 代码的 HttpResult）标头：

HTTP/1.1 304 Not Modified
Content-Length: 0
Content-Type: application/json
Server: Microsoft-HTTPAPI/2.0
X-Powered-By: ServiceStack/3.94 Win32NT/.NET
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, PUT, DELETE, OPTIONS
Access-Control-Allow-Headers: Content-Type
Date: Tue, 07 Aug 2012 13:39:19 GMT

如何防止其他标头被输出？我用HttpResult 尝试了各种方法，注册了一个虚拟内容类型过滤器，但顾名思义，它只控制内容，而不是标题，或者here 列出的其他内容。我还尝试使用 IStreamWriter 和 IHasOptions 实现我自己的 IHttpResult 衍生产品，结果相同：ServiceStack 添加了不需要的标头。

谢谢

更新

能够使用以下命令删除content-type，但仍然存在一些标头，即content-length、server 和date。

    public override object OnGet(FaultTypes request)
    {
      var result = new HttpResult
      {
       StatusCode = HttpStatusCode.NotModified,
       StatusDescription = "Not Modified", // Otherwise NotModified written!
      };

      // The following are hacks to remove as much HTTP headers as possible
      result.ResponseFilter = new NotModifiedContentTypeWriter();
      // Removes the content-type header
      base.Request.ResponseContentType = string.Empty;

      return result;
    }

class NotModifiedContentTypeWriter : ServiceStack.ServiceHost.IContentTypeWriter
{
  ServiceStack.ServiceHost.ResponseSerializerDelegate ServiceStack.ServiceHost.IContentTypeWriter.GetResponseSerializer(string contentType)
  {
    return ResponseSerializerDelegate;
  }

  void ServiceStack.ServiceHost.IContentTypeWriter.SerializeToResponse(ServiceStack.ServiceHost.IRequestContext requestContext, object response, ServiceStack.ServiceHost.IHttpResponse httpRes)
  {
  }

  void ServiceStack.ServiceHost.IContentTypeWriter.SerializeToStream(ServiceStack.ServiceHost.IRequestContext requestContext, object response, System.IO.Stream toStream)
  {
  }

  string ServiceStack.ServiceHost.IContentTypeWriter.SerializeToString(ServiceStack.ServiceHost.IRequestContext requestContext, object response)
  {
    return string.Empty;
  }

  public void ResponseSerializerDelegate(ServiceStack.ServiceHost.IRequestContext requestContext, object dto, ServiceStack.ServiceHost.IHttpResponse httpRes)
  {
  }
}

Answer 1

实际上你可以在你的 API 中做这样的事情

base.Response.StatusCode = (int) HttpStatusCode.NotModified;
base.Response.EndHttpRequestWithNoContent();
return new HttpResult();

不会返回 ContentType、ContentLength 等

Answer 2

ServiceStack 发出的唯一标头是在EndpointHostConfig.GlobalResponseHeaders 中注册的标头。

如果您不希望它们发出，请将它们删除，例如：

SetConfig(new EndpointHostConfig { 
    GlobalResponseHeaders = new Dictionary<string,string>()
});

您可以使用 HttpResult 临时添加它们，例如：

return new HttpResult(dto) {
    Headers = {
       { "Access-Control-Allow-Origin", "*" },
       { "Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS" } 
       { "Access-Control-Allow-Headers", "Content-Type" }, }
};

这两个选项在servicestack REST API and CORS进行了更详细的解释