C# 判断设备是否在线

1  ping类

using System;
using System.Collections.Generic;
using System.Text;
using System.Net.NetworkInformation;
using System.Threading;
using System.Windows.Forms;

namespace TestLoadForm
{
    class PingIp
    {
        Thread thread;
        int ping_time = 2000;
        System.Timers.Timer timer;
        public string Ip;
        public delegate void PingHandle(string ip,bool flag);
        public event PingHandle pingEvent;
        
        public PingIp(string ip)
        {
            Ip = ip;
            thread = new Thread(new ThreadStart(RunSecondThread));
            thread.Start();
        }

        void RunSecondThread()
        {
            timer = new System.Timers.Timer(ping_time);
            timer.AutoReset = true;
            timer.Enabled = true;
            timer.Elapsed += new System.Timers.ElapsedEventHandler(t_Elapsed);
        }

        void t_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            if (PingStop == false)
            {
                AutoPingIP(Ip);
            }
            else
            {
                timer.Stop();
            }
        }

        bool PingStop = false;

        void AutoPingIP(string ip)
        {
            Ping p = new Ping();
            PingOptions ops = new PingOptions();
            ops.DontFragment = true;
            string d = "test data";
            byte[] buf = Encoding.ASCII.GetBytes(d);
            int timeout = 3000;

            PingReply pr = p.Send(ip, timeout, buf, ops);
            if(ip != "")
            {
                if (pr.Status == IPStatus.Success)
                {
                    if (pingEvent != null)
                        pingEvent(ip,true);
                }
                else
                {
                    if (pingEvent != null )
                    {
                        PingStop = true;
                        pingEvent(ip,false);
                    }
                }
            }
        }
        
        public void StopTh()
        {
            if (timer != null)
            {
                timer.Dispose();
            }
            if (thread != null)
            {
                if (thread.IsAlive)
                    thread.Abort();
            }
        }
    }
}

2 测试

 public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        PingIp ping;
        private void Form1_Load(object sender, EventArgs e)
        {
            ping = new PingIp("192.168.100.204");
            ping.pingEvent += new PingIp.PingHandle(ping_pingEvent);
        }

        void ping_pingEvent(string ip, bool flag)
        {
           this.Invoke(new MethodInvoker(delegate()
            {
                textBox1.Text += "ip:"+ip+" state:"+flag+"\r\n";
            }
           ));
        }

    }

3 效果图