Question

I´m using Kayak server for a small project. It works great, but i have a problem when i have a request for a png or jpg image

First of all the code is here:

public class RequestDelegate : IHttpRequestDelegate{
*****
 public void OnRequest(HttpRequestHead request, IDataProducer requestBody,IHttpResponseDelegate response){
*****
else if (url.EndsWith("png"))
            {
                String fileName = url.Substring(url.IndexOf(@"\") + 1);
                url = url.Substring(url.IndexOf(@"\") + 1);
                url = Path.Combine(WebServerUtils.Instance.HtmlURL, url);
                using (StreamReader streamReader = new StreamReader(url))
                {
                    String body = streamReader.ReadToEnd();
                    var responseHeader = WebServerUtils.Instance.CreateResponseHeader(body.Length, "image/png");
                    responseHeader.Headers.Add("Content-Disposition", "attachment; filename=" + fileName);
                    response.OnResponse(responseHeader, new BufferedProducer(body));
                }
            }

****
}

This code is executed when a png image is requested. It’s very simple I locate the real url path of the image, the i read it with a stream reader. Then i create the response header..

this part of code

var responseHeader = WebServerUtils.Instance.CreateResponseHeader(body.Length, "image/png");

here is the implementation

public HttpResponseHead CreateResponseHeader(int length, String type)
        {
            var _ResponseHeader = new HttpResponseHead()
            {
                Status = "200 OK",
                Headers = new Dictionary<string, string>(){
                    { "Content-Type", type },
                    { "Content-Length", length.ToString() },
                }
            };
            return _ResponseHeader;
        }

Now here is the situation when i ask for the page non of the images are rendered. When i use Firebug to see what happen.. here is the error

Image corrupt or truncated: http://localhost:9090/Pedidos/back.png

Am I missing something when i’m building the response header?

I can not return properly an image..

Thanks in advance hope be clear with the explanation.

Answer 1

Well, it was very simple.. i´m using a Stream reader ( it inheritance from Text Reader).. I must use a memory stream in place of a Stream reader.

Here is the code:

byte[] byteArray = new byte[0];
                using (Image img = Image.FromFile(url))
                {

                    using (MemoryStream stream = new MemoryStream())
                    {
                        img.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
                        stream.Close();
                        byteArray = stream.ToArray();
                    }

                }

                String contentType = url.EndsWith("jpg") ? "image/jpg" : "image/png";
                var responseHeader = WebServerUtils.Instance.CreateResponseHeader(byteArray.Length, contentType);
                responseHeader.Headers.Add("Content-Disposition", "attachment; filename=" + fileName);
                response.OnResponse(responseHeader, new BufferedProducer(byteArray));