public static void DownloadFile(string strFilePath)
{
FileInfo download = new FileInfo(strFilePath);
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.Buffer = false;
HttpContext.Current.Response.ContentType = "application/octet-stream";
HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(download.FullName, System.Text.Encoding.UTF8));
HttpContext.Current.Response.AppendHeader("Content-Length", download.Length.ToString());
HttpContext.Current.Response.WriteFile(download.FullName);
HttpContext.Current.Response.Flush();
HttpContext.Current.Response.End();
}