生成html页面出错！


protected override void Render(HtmlTextWriter writer)
        {
            string StaticUrl = "~/Html/StockContract.html";
            if (!Directory.Exists(HttpContext.Current.Server.MapPath("~/Html/")))
            {
                Directory.CreateDirectory(HttpContext.Current.Server.MapPath("~/Html/"));
            }
            System.IO.StringWriter html = new System.IO.StringWriter();
            System.Web.UI.HtmlTextWriter tw = new System.Web.UI.HtmlTextWriter(html);
            base.Render(tw);
            System.IO.StreamWriter sw;
            sw = new System.IO.StreamWriter(Server.MapPath(StaticUrl), false, System.Text.Encoding.UTF8);
            sw.Write(html.ToString());
            sw.Close();
            tw.Close();
            Response.Write(html.ToString());
        }页面数据不动，   生成的html没问题！
如果改了数据。   就出错！。html里就出现以下的代码