ASP.NET Web Api 2 - Internet Explorer: The process cannot access the file because it is being used by another process

Question

I have a Restful ASP.NET Web API 2 with the following method that returns a HttpResponseMessage with an image as content:

[AllowAnonymous]
[HttpGet, Route("{id}/image/"]
    public HttpResponseMessage GetImage(int id)
    {
        try
        {
            var artwork = Service.GetSingle(id);

            if(!isValidArtwork(artwork)) {
                 Request.CreateResponse(HttpStatusCode.NotFound); 
            }

            string mediaHeaderValue;
            switch (Path.GetExtension(artwork.filePath))
            {
                case ".jpg":
                    mediaHeaderValue = "image/jpg";
                    break;
                case ".jpeg":
                    mediaHeaderValue = "image/jpg";
                    break;
                case ".bmp":
                    mediaHeaderValue = "image/jpg";
                    break;
                case ".png":
                    mediaHeaderValue = "image/png";
                    break;
                default:
                    return new HttpResponseMessage(HttpStatusCode.NotFound);
            }

            using(var fileStream = File.Open(artwork.filePath, FileMode.Open, FileAccess.Read)){

                var response = new HttpResponseMessage { Content = new StreamContent(fileStream) };
                response.Content.Headers.ContentType = new MediaTypeHeaderValue(mediaHeaderValue);
                response.Content.Headers.ContentLength = fileStream.Length;

                return response;
            }
        }
        catch (Exception){
            return Request.CreateResponse(HttpStatusCode.NotFound);
        }
    }

The method is working as intended in Chrome/Opera/Mozilla but in Internet Explorer (version 10/11), the following error is thrown: "The process cannot access the file because it is being used by another process".

I've tried different ways of closing/disposing the stream, using different file access attributes and setting the content as a byte array. However, the same error appears when using Internet Explorer (version 10/11).

Any suggestions on how this can be resolved? Or had similar problems with Internet Explorer (version 10/11)?

Answer 1

It is weird that this behaviour only triggers when the request is made from Internet Explorer. However, I've managed to find a solution. I was missing the FileShare.Read attribute when opening the file.

var fileStream = File.Open(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);

I've found another solution too. Copying the image data to a byte array, and disposing the file stream. Then use the byte array as content of the response message.