判断是否连网

1、using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Net.NetworkInformation;

namespace 判断是否联网

{

class Program

{

static void Main(string[] args)

{

Ping p = new Ping();

PingReply pr;

pr = p.Send("119.75.218.45");//百度的IP

if (pr.Status != IPStatus.Success)//如果连接不成功

{

Console.WriteLine("未联网");

}

else

{

Console.WriteLine("已联网");

}

Console.Read();

}

}

}

2、

  WebRequest myrequest = WebRequest.Create("http://www.baidu.com");
            WebResponse myres = null;
            try
            {


                myres = myrequest.GetResponse();
                myres.Close();
                MessageBox.Show("连上了");
            }
            catch (Exception)
            {


                MessageBox.Show("连不上了");
            }

3、

public partial class Form1 : Form
{
        //判断网络连接
        [DllImport("wininet")]
        private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);
        ///<summary>
        /// 检测本机的网络连接
        ///</summary>
 
       private void button1_Click(object sender, EventArgs e)
        {
            //判断是否联网
                int i = 0;
                if (InternetGetConnectedState(out i, 0))
                {
                    //联网
                    MessageBox.Show("Thylx提醒您：你的计算机已连接到网络上！");
                 }
                 else
                  {
                     //断网
                     MessageBox.Show("Thylx提醒您：本地连接已断开！");
                  }
        }
}