How to export data from datatable/dataset in pdf format (without using any 3rd party dll.)

using (StringWriter sw = new StringWriter())
   {
       using (HtmlTextWriter hw = new HtmlTextWriter(sw))
       {
           //To Export all pages
           GridView1.AllowPaging = false;
           this.BindGrid();

           GridView1.RenderControl(hw);
           StringReader sr = new StringReader(sw.ToString());
           Document pdfDoc = new Document(PageSize.A2, 10f, 10f, 10f, 0f);
           HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
           PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
           pdfDoc.Open();
           htmlparser.Parse(sr);
           pdfDoc.Close();

           Response.ContentType = "application/pdf";
           Response.AddHeader("content-disposition", "attachment;filename=GridViewExport.pdf");
           Response.Cache.SetCacheability(HttpCacheability.NoCache);
           Response.Write(pdfDoc);
           Response.End();
       }