ASP.NET Web API to return images

Question

I've been spinning my tires trying to use ASP.NET Web API to return images. I've seen a number of examples, but I keep running into problems.

After searching for a solution, most examples suggest using HttpResponseMessage and setting the Content and Content-Type header correctly. For example in the following posts: WebApi: How to handle Images ASP .Net Web API downloading images as binary

Here's what I am doing now:

    [System.Web.Http.HttpGet]
    [ActionName("ConvertHTMLToImage")]
    public HttpResponseMessage ConvertHTMLToImage(string htmlString)
    {
        var path = @"C:\temp\mona-lisa.png";
        var response = Request.CreateResponse(HttpStatusCode.OK);
        var fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
        response.Content = new StreamContent(fileStream);
        response.Content.Headers.ContentType = new MediaTypeHeaderValue("image/png");
        return response;
    }

I'm getting mixed results. When I go the URL for that resource I have problems with Chrome (This webpage is not available), Firefox (The connection was reset), and Safari (Safari can’t open the page). Much to my surprise, it works fine in IE. I can also successfully view the image using the composer in Fiddler. If I keep Fiddler open and access the resource using Chrome/Firefox/Safari, I see 504 errors. Not sure what the means, I can't remember ever having seen that error type before.

I also noticed some strange behavior in the debugger with the browsers that aren't working. If I call ConvertHTMLToImage from IE and Fiddler, I see it stop at my break-point once and then the image is sucessfully returned to the client. On Chrome/Firefox/Safari there are multiple calls into the method. Sometimes twice sometimes 3 times. I have no explanation for this. I don't get any errors that I can detect other than the browser doesn't show the image.

I've done this same thing using aspx pages, HttpHhandlers, and other .NET methods so I know there are work-arounds, but I really would like to know what I'm doing wrong. This seems like something that should be easily accomplished using the Web API.

Answer 1

This solved the issue for me WebApi: How to handle Images

In short

[System.Web.Http.HttpGet]
[ActionName("ConvertHTMLToImage")]
public HttpResponseMessage ConvertHTMLToImage()
{  
     string filePath = @"C:\temp\mona-lisa.png";

     var result = new HttpResponseMessage(HttpStatusCode.OK);

     FileStream fileStream = new FileStream(filePath, FileMode.Open);
     Image image = Image.FromStream(fileStream);
     MemoryStream memoryStream = new MemoryStream();
     image.Save(memoryStream, ImageFormat.Jpeg);

     result.Content = new ByteArrayContent(memoryStream.ToArray());
     result.Content.Headers.ContentType = new  MediaTypeHeaderValue("image/jpeg");
     return result;
}