When to use HttpResponseMessage and Request.CreateResponse

Question

When should we use the HttpResponseMessage object and when should we use the Request.CreateResponse(...) method?

Also, what is the differen

Answer 1

Request.CreateResponse(...) is just a builder, it also returns instance of HttpResponseMessage, here is the code:

public static HttpResponseMessage CreateResponse(this HttpRequestMessage request, HttpStatusCode statusCode, T value, HttpConfiguration configuration)
{
  if (request == null)
    throw Error.ArgumentNull("request");
  configuration = configuration ?? HttpRequestMessageExtensions.GetConfiguration(request);
  if (configuration == null)
    throw Error.InvalidOperation(SRResources.HttpRequestMessageExtensions_NoConfiguration, new object[0]);
  IContentNegotiator contentNegotiator = ServicesExtensions.GetContentNegotiator(configuration.Services);
  if (contentNegotiator == null)
  {
    throw Error.InvalidOperation(SRResources.HttpRequestMessageExtensions_NoContentNegotiator, new object[1]
    {
      (object) typeof (IContentNegotiator).FullName
    });
  }
  else
  {
    IEnumerable formatters = (IEnumerable) configuration.Formatters;
    ContentNegotiationResult negotiationResult = contentNegotiator.Negotiate(typeof (T), request, formatters);
    if (negotiationResult == null)
    {
      return new HttpResponseMessage()
      {
        StatusCode = HttpStatusCode.NotAcceptable,
        RequestMessage = request
      };
    }
    else
    {
      MediaTypeHeaderValue mediaType = negotiationResult.MediaType;
      return new HttpResponseMessage()
      {
        Content = (HttpContent) new ObjectContent(value, negotiationResult.Formatter, mediaType),
        StatusCode = statusCode,
        RequestMessage = request
      };
    }
  }