文件下载 http 报头

private void DownloadFile(RepeaterCommandEventArgs e)         {            

　　string fileName = e.CommandArgument as string;            

　　string path = this.Server.MapPath("../images");            

　　string fullpath = string.Format("{0}/{1}", path, fileName);

       

　　//这里主要用于下载                 

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

　　string headerValue = string.Format("attachment; filename={0}", this.Server.UrlEncode(fileName));            

　　Response.AddHeader("Content-Disposition", headerValue);  

                      

　　Response.Clear();            

　　Response.TransmitFile(fullpath);            

　　Response.End();

        }