Right way to return JSON from Asp.net web api 2 filter attribute response

Question

I am working with ASP.NET Web Api 2. I have created a action filter which checks for incoming request and then return a response back based on certain condition.

public override void OnAuthorization(HttpActionContext actionContext)
        {
            var req = actionContext.Request;
            if (!req.Headers.Contains("x-key") || req.Headers.GetValues("x-key") == null)
            {
                actionContext.Response = req.CreateResponse(HttpStatusCode.Unauthorized);
                actionContext.Response.Content = new StringContent("Token required", Encoding.UTF8, "text/html");
            }
        }

I want to know is this the right way to return JSON response? I want to return a custom object ( var rebBody = new {message = "Unauthorized", payload = "", response = "401"};) as JSON in the response body.

Does it make sense to use something like this:

 var v = new {message = "Unauthorized", payload = "", response = "401"};
                actionContext.Response.Content = new ObjectContent<object>(v, new JsonMediaTypeFormatter(), "application/json");

Answer 1

You can use another overload of CreateResponse:

public static HttpResponseMessage CreateResponse<T>(
    this HttpRequestMessage request,
    T value)

e.g:

var content = new { Property = 1 };
request.CreateResponse(content);

See: https://msdn.microsoft.com/en-us/library/system.net.http.httprequestmessageextensions.createresponse(v=vs.118).aspx

Answer 2

Something like this perhaps,

    public override void OnAuthorization(HttpActionContext actionContext)
    {
        var req = actionContext.Request;
        if (!req.Headers.Contains("x-key") || req.Headers.GetValues("x-key") == null)
        {
            HttpResponseMessage responseMessage = new HttpResponseMessage()
            {
                Content = new StringContent("{\"message\":\"Unauthorized\", \"payload\":\"\",\"response\":\"401\"}")
            };
            responseMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
            actionContext.Response = responseMessage;
        }
    }

or like this:

       public override void OnAuthorization(HttpActionContext actionContext)
    {
        var req = actionContext.Request;
        if (!req.Headers.Contains("x-key") || req.Headers.GetValues("x-key") == null)
        {
            var v = new { message = "Unauthorized", payload = "", response = "401" };
            HttpResponseMessage responseMessage = new HttpResponseMessage()
            {
                StatusCode = HttpStatusCodes.Unauthorized,
                Content = new StringContent(JsonConvert.SerializeObject(v))
            };
            responseMessage.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
            actionContext.Response = responseMessage;
        }
    }