ASP.NET

System.IO.File.Create("file.txt");

private void ExporttoExcel(string xmlPath)
       {

           HttpResponse response = HttpContext.Current.Response;

           // first let's clean up the response.object
           response.Clear();
           response.Charset = "";
           // set the response mime type for excel
           response.ContentType = "application/ms-excel";

           DataSet xportdata = new DataSet();
           xportdata.ReadXml(xmlPath);

           if (xportdata != null)
           {
               if (xportdata.Tables.Count > 0)
               {
                   if (xportdata.Tables[0].Rows.Count > 0)
                   {

                       StringWriter sw = new StringWriter();
                       HtmlTextWriter htw = new HtmlTextWriter(sw);
                       GridView gv = new GridView();
                       gv.DataSource = xportdata.Tables[0];
                       gv.DataBind();
                       gv.RenderControl(htw);
                       Response.Write(sw.ToString());
                       Response.End();
                   }
                   else
                   {
                       lblErrorMessage.Text = "No Records Found.";
                   }
               }
               else
               {
                   lblErrorMessage.Text = "No Records Found.";
                   Response.Flush();
                   //Response.End();
               }
           }
       }

DataTable dt = new DataTable();
                   dt.Columns.Add("ID");
                   dt.Columns.Add("Name");
                   dt.Columns.Add("Year");

DataView dv = dt.DefaultView;
                   rpt1.DataSource = dv;
                   rpt1.DataBind();

<asp:Repeater ID = "rpt1" runat="server" 
    onitemdatabound="rpt1_ItemDataBound" 
    onitemcommand="rpt1_ItemCommand" >
    <ItemTemplate>
        <asp:Label ID = "lbl_Year" runat="server" Text='<%# Eval("Year") %>'/></li>
         <asp:Label ID = "lbl_Name" runat="server" Text='<%# Eval("Name") %>'/>
         <asp:Label ID = "lbl_ID" runat="server" Text='<%# Eval("ID") %>' />
    </ItemTemplate>
    
    </asp:Repeater>