如何使用gridview 读取数据

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using MySql.Data;
using MySql.Data.MySqlClient;
using System.Data.SqlClient;
using System.Configuration;

namespace test
{
    public partial class index : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string connectionString = @"data source=.SQLEXPRESS;initial catalog=test;persist security info=True;user id=sa;password=123456"; //Pooling=False;
            SqlConnection conn = new SqlConnection(connectionString);
            conn.Open();
            Response.Write(conn.State);
            SqlCommand cmd = new SqlCommand("select * from admin", conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds, "admin");
            this.GridView1.DataSource = ds.Tables[0].DefaultView;  // 需要在index.aspx下创建一个控件.gridview
            this.DataBind();

        }

        protected void s(object sender, EventArgs e)
        {

        }

        protected void lnklogin_Click(object sender, EventArgs e)
        {

        }
    }
}f