c#判断是否联网

方法一： 

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(); 

   

         } 

     } 

 }

 

 

c#关于判断网络连接正常与否的总结 
本人最近做c#winform的项目，遇到了判断网络是否正常连接的问题。后来查出了以下几种方法，供大家学习参考。

1.方法二（用异步调用)

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Windows.Forms;

using System.Net.Sockets;

using System.Threading;

namespace WindowsFormsApplication1

{

    public partial class Demo : Form

    {

        public Demo()

        {

            InitializeComponent();

        }

        //判断

        private void btpanduan_Click(object sender, EventArgs e)

        {

            //210.192.120.228  163网易

            string ip = this.txtip.Text.ToString();

            int port = Convert .ToInt32( this.txtport.Text.ToString());

            bool a = panduan(ip, port );//135为本机服务端口号

            if (a == true)

            {

                MessageBox.Show("该网络连接正常 ！");

            }

            else

            {

                MessageBox.Show("该网络连接不畅通 ！");

            }

        }

     

      // 异步调用

        //判断的方法

        public bool panduan(string ip, int port)

        {

            try

            {

                TcpClient client = new TcpClient(ip, port);

                if (client.Connected)

                {

                    return true;

                }

                else

                {

                    return false;

                }

            }

            catch

            {

                return false;

            }

        }

    }

}

2.利用 c# ping类

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Net;

namespace WindowsFormsApplication1

{

    public partial class Demo3 : Form

    {

        public Demo3()

        {

            InitializeComponent();

        }

        System.Net.NetworkInformation.Ping ping = new System.Net.NetworkInformation.Ping();

        System.Net.NetworkInformation.PingReply res;

        //检查网络连接

        private void btcheck_Click(object sender, EventArgs e)

        {

            string url = this.txturl.Text.ToString();

            bool a = check(url);

            if (a == true)

            {

                MessageBox.Show("连接成功！", "提示信息");

            }

            else

            {

                MessageBox.Show("连接失败！", "提示信息");

            }

        }

        public bool check(string url)

        {

            try

            {

                res = ping.Send(url);

                if (res.Status == System.Net.NetworkInformation.IPStatus.Success)

                {

                    return true;

                }

                else

                {

                    return false;

                }

            }

            catch {

                return false;

            }

        }

    }

}