How to Export ASP.NET GridView to MS EXCEL and MS Word

  #region Export

        public override void VerifyRenderingInServerForm(Control control)

        {

            /* Verifies that the control is rendered */

        }

        /// <summary>

        /// This event is used to export gridview data to word document

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        protected void btnWord_Click(object sender, ImageClickEventArgs e)

        {

            GridView1.AllowPaging = false;

            GridView1.AllowSorting = false;

            GridView1.Columns[6].Visible = false;

            GridView1.DataBind();

            Response.ClearContent();

            Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", "ScratchCardNo.doc"));

            Response.ContentEncoding = Encoding.GetEncoding("ISO-8859-1"); //must

            Response.Charset = "ISO-8859-1"; //optional

            Response.ContentType = "application/ms-word";

            StringWriter sw = new StringWriter();

            HtmlTextWriter htw = new HtmlTextWriter(sw);

            GridView1.RenderControl(htw);

            Response.Write(sw.ToString());

            Response.End();

        }

        /// <summary>

        /// This Event is used to export gridview data to Excel

        /// </summary>

        /// <param name="sender"></param>

        /// <param name="e"></param>

        protected void btnExcel_Click(object sender, ImageClickEventArgs e)

        {

            Response.ClearContent();

            Response.Buffer = true;

            Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", "ScratchCardNo.xls"));

            Response.ContentType = "application/ms-excel";

            Response.ContentEncoding = Encoding.GetEncoding("ISO-8859-1"); //must

            Response.Charset = "ISO-8859-1"; //optional

            StringWriter sw = new StringWriter();

            HtmlTextWriter htw = new HtmlTextWriter(sw);

            GridView1.AllowPaging = false;

            GridView1.AllowSorting = false;

            GridView1.Columns[6].Visible = false;

            GridView1.DataBind();

            ////Change the Header Row back to white color

            //GridView1.HeaderRow.Style.Add("background-color", "#FFFFFF");

            ////Applying stlye to gridview header cells

            //for (int i = 0; i < GridView1.HeaderRow.Cells.Count; i++)

            //{

            //    GridView1.HeaderRow.Cells[i].Style.Add("background-color", "#507CD1");

            //}

            //int j = 1;

            ////This loop is used to apply stlye to cells based on particular row

            //foreach (GridViewRow gvrow in GridView1.Rows)

            //{

            //    gvrow.BackColor = Color.White;

            //    if (j <= GridView1.Rows.Count)

            //    {

            //        if (j % 2 != 0)

            //        {

            //            for (int k = 0; k < gvrow.Cells.Count; k++)

            //            {

            //                gvrow.Cells[k].Style.Add("background-color", "#EFF3FB");

            //            }

            //        }

            //    }

            //    j++;

            //}

            GridView1.RenderControl(htw);

            Response.Write(sw.ToString());

            Response.End();

        }

        #endregion

Notes:

Add EnableEventValidation="false" to Page Property.

Avoid UpdatePanel in the Page.
if you use UpdatePanel then use

<Triggers>

   <asp:PostBackTrigger ControlID="btnWord" />

   <asp:PostBackTrigger ControlID="btnExcel" />

</Triggers>

Other  help:

Adding Serial Number to ASP.NET GridView

<asp:TemplateField HeaderText="S/N">

                            <ItemTemplate>

                                <asp:Label ID="lblNo" runat="server" Text='<%# Container.DataItemIndex + 1 %>' />

                            </ItemTemplate>

                        </asp:TemplateField>