Return content with IHttpActionResult for non-OK response

Question

For returning from a Web API 2 controller, I can return content with the response if the response is OK (status 200) like this:

public IHttpActionResult Get()
{
    string myResult = ...
    return Ok(myResult);
}

If possible, I want to use the built-in result types here when possible

My question is, for another type of response (not 200), how can I return a message (string) with it? For example, I can do this:

public IHttpActionResult Get()
{
    return InternalServerError();
}

but not this:

public IHttpActionResult Get()
{
    return InternalServerError("Message describing the error here");
}

Ideally, I want this to be generalized so that I can send a message back with any of the implementations of IHttpActionResult.

Do I need to do this (and build my response message):

public IHttpActionResult Get()
{
    HttpResponseMessage responseMessage = ...;
    return ResponseMessage(responseMessage);
}

or is there a better way?

Answer 1

I ended up going with the following solution:

public class HttpActionResult : IHttpActionResult
{
    private readonly string _message;
    private readonly HttpStatusCode _statusCode;

    public HttpActionResult(HttpStatusCode statusCode, string message)
    {
        _statusCode = statusCode;
        _message = message;
    }

    public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
    {
        HttpResponseMessage response = new HttpResponseMessage(_statusCode)
        {
            Content = new StringContent(_message)
        };
        return Task.FromResult(response);
    }
}

... which can be used like this:

public IHttpActionResult Get()
{
   return new HttpActionResult(HttpStatusCode.InternalServerError, "error message"); // can use any HTTP status code
}

I'm open to suggestions for improvement. :)