Export to Excell GridView / Datatable / Dataset ?

Step 1: add this to Page where GridView exists.


 public override void VerifyRenderingInServerForm(Control control)
    {
        /* Confirms that an HtmlForm control is rendered for the specified ASP.NET
           server control at run time. */
    }

Step 2: Add this class to Project.


  public class ExportToExcelClass
    {

        public void ExportToExcel(GridView gridview, string TitleforExcel)
        {
            HttpResponse response = HttpContext.Current.Response;

            response.Clear();
            response.Buffer = true;
            response.ClearContent();
            response.ClearHeaders();
            response.Charset = "";
            string FileName = TitleforExcel + "_" + DateTime.Now + ".xls";
            StringWriter strwritter = new StringWriter();
            HtmlTextWriter htmltextwritter = new HtmlTextWriter(strwritter);
            response.Cache.SetCacheability(HttpCacheability.NoCache);
            response.ContentType = "application/vnd.ms-excel";
            response.AddHeader("Content-Disposition", "attachment;filename=" + FileName);
                    
            gridview.GridLines = GridLines.Both;
            gridview.HeaderStyle.Font.Bold = true;
            gridview.RenderControl(htmltextwritter);
            response.Write(strwritter.ToString());
            response.End();

        }

        public void ExportToExcel(DataSet ds, string TitleforExcel)
        {
            HttpResponse response = HttpContext.Current.Response;

            // first let's clean up the response.object
            response.Clear();
            response.Charset = "";
            string FileName = TitleforExcel + "_" + DateTime.Now + ".xls";
            // set the response mime type for excel
            response.ContentType = "application/vnd.ms-excel";
            response.AddHeader("Content-Disposition", "attachment;filename=\"" + FileName);

            // create a string writer
            using (StringWriter sw = new StringWriter())
            {
                using (HtmlTextWriter htw = new HtmlTextWriter(sw))
                {
                    // instantiate a datagrid
                    DataGrid dg = new DataGrid();
                    dg.DataSource = ds.Tables[0];
                    dg.DataBind();
                    dg.RenderControl(htw);
                    response.Write(sw.ToString());
                    response.End();
                }
            }
        }

        public void ExportToExcel(DataTable dt, string TitleforExcel)
        {
            HttpResponse response = HttpContext.Current.Response;

            // first let's clean up the response.object
            response.Clear();
            response.Charset = "";
            string FileName = TitleforExcel + "_" + DateTime.Now + ".xls";
            // set the response mime type for excel
            response.ContentType = "application/vnd.ms-excel";
            response.AddHeader("Content-Disposition", "attachment;filename=\"" + FileName);

            // create a string writer
            using (StringWriter sw = new StringWriter())
            {
                using (HtmlTextWriter htw = new HtmlTextWriter(sw))
                {
                    // instantiate a datagrid
                    DataGrid dg = new DataGrid();
                    dg.DataSource = dt;
                    dg.DataBind();
                    dg.RenderControl(htw);
                    response.Write(sw.ToString());
                    response.End();
                }
            }
        }
    }