webapistream.cs

public class FastController : ApiController
{
    [Route("")]
    public HttpResponseMessage GetResult()
    {
        var fs = new FileStream(Path.Combine(HttpRuntime.AppDomainAppPath, "medline13n0701.xml.gz"), FileMode.Open);
        var response = new HttpResponseMessage(HttpStatusCode.OK)
        {
            Content = new StreamContent(fs)
        };
        response.Content.Heades.ContentType = new MediaTypeHeaderValue("application/xml");
        response.Content.Headers.ContentEncoding.Add("gzip");
        return response;
    }
}