Export to excel gridview content

private void ExportToExcel(string strFileName, GridView dg)

        {

            DataTable dt = GetData();

           

            dg.AllowPaging = false;

            dg.DataSource = dt;

            dg.DataBind();

            Response.ClearContent();

            Response.AddHeader("content-disposition", "attachment; filename=" + strFileName);

            Response.ContentType = "application/excel";

            System.IO.StringWriter sw = new System.IO.StringWriter();

            HtmlTextWriter htw = new HtmlTextWriter(sw);

           

            dg.RenderControl(htw);

            Response.Write(sw.ToString());

            Response.End();

        }