The network path was not found error IOException was not handled

public void ProcessRequest(HttpContext context)
        {
            string imagePath = context.Request.QueryString["image"];

            // split the string on periods and read the last element, this is to ensure we have
            // the right ContentType if the file is named something like "image1.jpg.png"
            string[] imageArray = imagePath.Split('.');

            if (imageArray.Length <= 1)
            {
                throw new HttpException(404, "Invalid photo name.");
            }
            else
            {
                FileStream file = new FileStream(imagePath,FileMode.Open);
                byte[] buffer = new byte[(int)file.Length];
                file.Read(buffer,0,(int)file.Length);
                file.Close();

                context.Response.ContentType = "application/octet-stream";

                ////context.Response.AddHeader("content-disposition","attachment
                context.Response.BinaryWrite(buffer);
                context.Response.End();
                //context.Response.Write(imagePath);
                //context.Response.ContentType = "image/" + imageArray[imageArray.Length - 1];
                //context.Response.WriteFile(imagePath);
            }
        }

        public bool IsReusable
        {
            get { return true; }
        }

    }
}