Generate PDF using itextsharp using asp.net with StringBuilder

//////////////// NameSpace

using iTextSharp.text;

using iTextSharp.text.pdf;

using iTextSharp.text.html;

using iTextSharp.text.html.simpleparser;

protected void Generate_PDF(object sender, EventArgs e)

    {

        //Dummy data for Invoice (Bill).

        string TagName= "Krishraja88";

        int Name= "Krishna";

        DataTable dt = new DataTable();

        dt.Columns.AddRange(new DataColumn[5] {

                            new DataColumn("ProductId", typeof(string)),

                            new DataColumn("Product", typeof(string)),

                            new DataColumn("Price", typeof(int)),

                            new DataColumn("Quantity", typeof(int)),

                            new DataColumn("Total", typeof(int))});

        dt.Rows.Add(101, "Product1", 2010, 5, 10020);

        dt.Rows.Add(102, "Product1", 4100, 2, 8010);

        dt.Rows.Add(103, "Product1", 3010, 3, 9200);

        dt.Rows.Add(104, "Product1", 5150, 2, 11300);

        using (StringWriter sw = new StringWriter())

        {

            using (HtmlTextWriter hw = new HtmlTextWriter(sw))

            {

                StringBuilder sb = new StringBuilder();

                //Generate Invoice (Bill) Header.

                sb.Append("<table width='100%' cellspacing='0' cellpadding='2'>");

                sb.Append("<tr><td align='center' style='background-color: #18B5F0' colspan = '2'><b>Order Sheet</b></td></tr>");

                sb.Append("<tr><td colspan = '2'></td></tr>");

                sb.Append("<tr><td><b>Name: </b>");

                sb.Append(Name);

                sb.Append("</td><td align = 'right'><b>Date: </b>");

                sb.Append(DateTime.Now);

                sb.Append(" </td></tr>");

                sb.Append("<tr><td colspan = '2'><b>Tag Name: </b>");

                sb.Append(TagName);

                sb.Append("</td></tr>");

                sb.Append("</table>");

                sb.Append("<br />");

                //Generate Invoice (Bill) Items Grid.

                sb.Append("<table border = '1'>");

                sb.Append("<tr>");

                foreach (DataColumn column in dt.Columns)

                {

                    sb.Append("<th style = 'background-color: #D20B0C;color:#ffffff'>");

                    sb.Append(column.ColumnName);

                    sb.Append("</th>");

                }

                sb.Append("</tr>");

                foreach (DataRow row in dt.Rows)

                {

                    sb.Append("<tr>");

                    foreach (DataColumn column in dt.Columns)

                    {

                        sb.Append("<td>");

                        sb.Append(row[column]);

                        sb.Append("</td>");

                    }

                    sb.Append("</tr>");

                }

                sb.Append("<tr><td align = 'right' colspan = '");

                sb.Append(dt.Columns.Count - 1);

                sb.Append("'>Total</td>");

                sb.Append("<td>");

                sb.Append(dt.Compute("sum(Total)", ""));

                sb.Append("</td>");

                sb.Append("</tr></table>");

                //Export HTML String as PDF.

                StringReader sr = new StringReader(sb.ToString());

                Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

                HTMLWorker htmlparser = new HTMLWorker(pdfDoc);

                PdfWriter writer = PdfWriter.GetInstance(pdfDoc, Response.OutputStream);

                pdfDoc.Open();

                htmlparser.Parse(sr);

                pdfDoc.Close();

                Response.ContentType = "application/pdf";

                Response.AddHeader("content-disposition", "attachment;filename=Invoice_" + orderNo + ".pdf");

                Response.Cache.SetCacheability(HttpCacheability.NoCache);

                Response.Write(pdfDoc);

                Response.End();

            }

        }

    }