从SQL中读取的数据流并实现下载

从数据库读出的文件流下载

private void Page_Load(object sender, System.EventArgs e)
        {
            string id = Request.QueryString["ID"] as string;
            IAccessoryRoot root = new AccessoryRoot(WebDefine.DBSealConn);
            AccessoryController ctrl = root.AccessoryController;
            Accessory a = ctrl.GetAccessory(id);
            if(a != null)
            {
        
                Response.Clear();
                //Response.ContentType = a.ContentType;
                Response.ContentType = "application/x-www-form-urlencoded";
                //Response.AddHeader("Content-Length", a.Size.ToString());
                Response.AddHeader("Content-Disposition", "attachment; filename=" + a.Name);
                Response.BinaryWrite(a.ContentBytes);

                Response.End();
                Response.Close();
            }
            else
            {
                Response.Write("文件不存在或已被删除.");
            }
        }