前台页面：

后台代码：

public readonly string conStr = ConfigurationManager.ConnectionStrings["sql"].ConnectionString;        protected void Page_Load(object sender, EventArgs e)        {            DataTable dt = GetTable();            if (dt.Rows.Count>0)            {                TestList.DataSource = dt;                TestList.DataTextField = "UserName";                TestList.DataValueField = "id";                TestList.DataBind();                TestList.Items.Insert(0, new ListItem("请选择设备...", "0"));            }        }        public DataTable GetTable()        {            DataTable dt = new DataTable();            string sql = "select * from tb_user";            using (SqlConnection conn=new SqlConnection(conStr))            {                SqlDataAdapter adapter = new SqlDataAdapter(sql,conn);                adapter.Fill(dt);            }            return dt;        }