ASP.NET tip: the easiest way to get from the data island to Excel

Simply set ContentType to "application/ vnd.ms-excel "to output.
as Excel The code is as follows :
DataToExcel.aspx:
< %@ Page Language="C#" AutoEventWireup="true" CodeFile="DataToExcel.aspx.cs" Inherits="DataToExcel" % >

< html xmlns="http://www.w3.org/1999/xhtml" >
< head runat="server" >
      < title > DataToExcel < /title >
< /head >
< body >
      < form id="form1" runat="server" >
                      < asp:GridView ID="GridView1" runat="server" >
                      < /asp:GridView >
      < /form >
< /body >
< /html > DataToExcel.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class DataToExcel : System.Web.UI.Page
{
      protected void Page_Load(object sender, EventArgs e)
      {
              if (!this.IsPostBack)
              {
                      this.Response.ContentType = "application/vnd.ms-excel";
                      string ConnStr = "server=localhost;uid=sa;pwd=;database=northwind";
                      SqlConnection Conn = new SqlConnection(ConnStr);
                      Conn.Open();
                      string sqlcmd = "select lastname,firstname,title, address, city from employees";
                      SqlCommand cmd = new SqlCommand(sqlcmd, Conn);
                      SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                      DataSet ds = new DataSet();
                      adapter.Fill(ds);
                      this.GridView1.DataSource = ds.Tables[0].DefaultView;
                      this.GridView1.DataBind();
              }
      }
}