Export data from panel to PDF internal grid view formatting not work in ASP.NET

Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
            HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
            PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
            string pdfFileName = Request.PhysicalApplicationPath + "\\files\\" + "DeliveryChalan" + FileName + ".pdf";
            string appPath = HttpContext.Current.Request.ApplicationPath;
            string path = Server.MapPath(appPath + "\\files\\" + "DeliveryChalan" + FileName + ".pdf");
            dynamic output = new FileStream(path, FileMode.Create);
            iTextSharp.text.pdf.PdfWriter.GetInstance(pdfDoc, output);
           //PdfWriter writer= iTextSharp.text.pdf.PdfWriter.GetInstance(pdfDoc, output);
            //writer.PageEvent = new Footer();

            pdfDoc.Open();
            //Paragraph welcomeParagraph = new Paragraph("Hello, World!");
          
            //pdfDoc.Add(welcomeParagraph);

            for (int i = 1; i <= 4; i++)
            {
                string Id = "pnldata" + i;
                Panel pnl = (Panel)FindControl(Id);

                using (StringWriter sw = new StringWriter())
                {
                    using (HtmlTextWriter hw = new HtmlTextWriter(sw))
                    {
                       
                        pdfDoc.SetPageSize(new Rectangle(595, 850));
                        var style = new StyleSheet();
                        style.LoadTagStyle("body", "size", "9px");
                        //style.LoadTagStyle("grdDeliverChallan2", "height", "500px");
                        htmlparser = new HTMLWorker(pdfDoc);
                        //htmlparser.SetStyleSheet(style);
                        //pdfDoc.PageSize.Height = 10;
                       
                        pdfDoc.NewPage();
                        //pdfDoc.PageSize
                        //const string V = @"vshsd";
                        //Chunk c1 = new Chunk("A chunk represents an isolated string. ");
                        //ColumnText.ShowTextAligned(writer.DirectContent, Element.ALIGN_RIGHT, V, 36, 820, 0);

                        pnl.RenderControl(hw);
                    
                        StringReader sr = new StringReader(sw.ToString());
                        htmlparser.Parse(sr);
                    }
                }
            }
           

            pdfDoc.Close();