Export Gridview data to Excel

i)  Get the Data from the Database and Bind it to the Gridview
ii) Set Gridview Allowpaging property to "False"

Write the below code to export the entire Gridview data to Excel sheet


 private void ExportGridView()
        {
                string style = @"<style> .text { mso-number-format:\@; } </style> ";
                string attachment = "attachment; filename=Contacts.xls";
                Response.ClearContent();
                Response.AddHeader("content-disposition", attachment);
                Response.ContentType = "application/ms-excel";
                StringWriter sw = new StringWriter();
                HtmlTextWriter htw = new HtmlTextWriter(sw);
          
                // Create a form to contain the grid
                HtmlForm frm = new HtmlForm();
                VerificationTrackingGridView.Parent.Controls.Add(frm);
                frm.Attributes["runat"] = "server";
                frm.Controls.Add(VerificationTrackingGridView);
                frm.RenderControl(htw);

                Response.Write(style);
                Response.Write(sw.ToString());
                Response.End();

        }