SqlConnection连SQL数据库通过web.config获取数据源

using System;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace simx
{
    public class lj:System.Web.UI.Page
    {
        private void Page_Load(object sender,System.EventArgs e)
        {
            if(!Page.IsPostBack)
            {
               getdata();
            }
        }

        private void InitializeComponent()
        {
       
        }
   
        private void getdata()
        {
           string sqlconn=ConfigurationSettings.AppSettings["CONN_STRING"];
           SqlConnection conn=new SqlConnection(sqlconn);
           conn.Open();
        }
    }
}

//web.config文件
<appSettings>
    <add key="CONN_STRING" value="Server=(lIP地址);User id=用户名;Pwd=密码;Database=数据库"></add>
</appSettings>