ASP.NET Web Api 2 Custom HttpResponseMessage

Question

I created a custom Result I use in the Web API Controller actions where I return a custom async Task<IHttpActionResult> .

 public class CustomResult<T> : NegotiatedContentResult<T>
 {

    public CustomResult(HttpStatusCode statusCode, T content, ApiController controller)
        : base(statusCode, content, controller)
    {
    }

    public CustomResult(HttpStatusCode statusCode, T content, IContentNegotiator contentNegotiator, HttpRequestMessage request, IEnumerable<MediaTypeFormatter> formatters)
        : base(statusCode, content, contentNegotiator, request, formatters) { }


    public override async Task<HttpResponseMessage> ExecuteAsync(System.Threading.CancellationToken cancellationToken)
    {
        HttpResponseMessage response = await base.ExecuteAsync(cancellationToken);            


        return response;
    }
}

And basically in my action I return it like this:

public async Task<IHttpActionResult> Register(RegisterViewModel model)
    {

       if (!ModelState.IsValid)
       {             
          return new CustomResult<string>(HttpStatusCode.BadRequest,"Model is invalid", this);                                        
       }
       else
       {
          return new CustomResult<string>(HttpStatusCode.Ok,"Model is valid", this);                                        
       } 

     }

The problem is the custom message I want to return. It doesn't work! If the model is invalid I always get the 400 Bad Request and the custom message: "The remote server returned the following error while establishing a connection - 'Bad Request' , instead of getting 400 Bad Request and my custom message Model is invalid .

This however works when I return 200 OK.

Is there something I am doing wrong?

Answer 1

Try to set

<system.webServer>
  <httpErrors existingResponse="PassThrough"/>
</system.webServer>

in web.config. PassThrough option - leaves the response untouched if an existing response exists. ( more about httperrors )