title: File download issue with api controller
body: <pre><code>public class DefaultController : Controller
  {
      // GET: Default
      public ActionResult Index()
      {
          return Download();
      }
  
      public FileResult Download()
      {
          string xmlString = "my test xml data";
          string fileName = "test" + ".xml";
          return File(Encoding.UTF8.GetBytes(xmlString), "application/xml", fileName);
      }
  }
  </code></pre>
  
  <p>I have the above code in asp.net mvc application to download a file. It worked fine as my controller is inherited to Controller. But when I move this code to Webapi controller it throws error at return <strong>File</strong>. After analysis I found that my controller in webapi is inheriting to ApiController(system.web.http.api controller). I found that there is no File class in ApiController. Is there any option to implement downloading file functionality in webapi controller?</p>
  
  <p>I tried the below alternative code in webapi controller but couldnt see a downloading file once I call this.</p>
  
  <pre><code>public HttpResponseMessage DownloadConstructedXmlFile()
          {
              var result = new HttpResponseMessage(HttpStatusCode.OK);
              string xmlContent = "My test xml data";
              //var serializer = new XmlSerializer(typeof(xmlContent));
  
              var builder = new StringBuilder();
              using (var writer = new StringWriter(builder))
              {
                  // serializer.Serialize(writer, xmlContent);
                  result.Content = new StringContent(xmlContent, Encoding.UTF8, "application/xml");
                  result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
                  {
                      FileName = string.Format("test.xml")
                  };
                 // return result;
              }
  
              return new HttpResponseMessage();
          }
  </code></pre>
  
  <p>PS: I am trying to use angularjs code to call this api through angular service.This is invoked on download button click. Any sample angular code or help in api controller code or suggestions would be helpful.</p>