快速局域网扫描,使用Ping类

有些小问题,主要是超时处理上.具体我都加了注释

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.Threading;
using System.Net;
using System.Net.Sockets;
using System.Net.NetworkInformation;

namespace PingLan
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        DateTime StartTime;
        public delegate void DelPing(object ip);

        private void PingIP(object obj)
        {
            IPAddress ipadd = (IPAddress)obj;
            Ping p = new Ping();
            PingOptions po = new PingOptions();
            po.DontFragment = true;
            //创建1个32字节的流
            string data = "012345678901234567890123456789ab";
            byte[] buffer = Encoding.ASCII.GetBytes(data);
            //超时,毫秒
            int timeout = 120;
            PingReply pr = p.Send(ipadd, timeout, buffer, po);
            //ping成功
            if (pr.Status == IPStatus.Success)
            {
                //线程调用
                if (listBox1.InvokeRequired)
                {
                    DelPing dp = new DelPing(PingIP);
                    this.Invoke(dp, new object[] { ipadd });
                }
                else
                {
                    listBox1.Items.Add(ipadd.ToString() + " 在线");
                    if (toolStripProgressBar1.Value != toolStripProgressBar1.Maximum)
                        toolStripProgressBar1.Value++;
                    //如果不检测超时IP,这里toolStripProgressBar1.Maximum要改
                    if (toolStripProgressBar1.Value == toolStripProgressBar1.Maximum)
                    {
                        MessageBox.Show("检测完成!", "完成", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                        button1.Enabled = true;
                        DateTime EndTime = DateTime.Now;
                        //时间间隔
                        TimeSpan ts = EndTime - StartTime;
                        toolStripStatusLabel1.Text = "用时: " + ts.Seconds.ToString();
                        toolStripProgressBar1.Value = toolStripProgressBar1.Minimum;
                    }
                }
            }
            //如果检测超时,会很慢,而且貌似有点问题,列表框会无响应一段时间
            //else//失败,IPStatus.TimedOut
            //{
            //    //线程调用
            //    if (listBox1.InvokeRequired)
            //    {
            //        DelPing dp = new DelPing(PingIP);
            //        this.Invoke(dp, new object[] { ipadd });
            //    }
            //    else
            //    {
            //        listBox1.Items.Add(ipadd.ToString() + " 离线");
            //        if (toolStripProgressBar1.Value != toolStripProgressBar1.Maximum)
            //            toolStripProgressBar1.Value++;
            //        if (toolStripProgressBar1.Value == toolStripProgressBar1.Maximum)
            //        {
            //            MessageBox.Show("检测完成!", "完成", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
            //            button1.Enabled = true;
            //            DateTime EndTime = DateTime.Now;
            //            //时间间隔
            //            TimeSpan ts = EndTime - StartTime;
            //            toolStripStatusLabel1.Text = "用时: " + ts.Seconds.ToString();
            //            toolStripProgressBar1.Value = toolStripProgressBar1.Minimum;
            //        }

            //    }
            //}
        }

        private void button1_Click(object sender, EventArgs e)
        {
            button1.Enabled = false;
            StartTime = DateTime.Now;
            string host;
            IPAddress ipadds;
            listBox1.Items.Clear();
            string mask = numericUpDown1.Value.ToString() + "." + numericUpDown2.Value.ToString() + "." + numericUpDown3.Value.ToString() + ".";
            int max = (int)numericUpDown5.Value;
            int min = (int)numericUpDown4.Value;
            if (min > max)
            {
                MessageBox.Show("IP地址范围错误!", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
                button1.Enabled = true;
                return;
            }
            else
            {
                int num = max - min + 1;
                //Thread[] tr = new Thread[num];
                toolStripProgressBar1.Minimum = min;
                //如果不检测超时IP,这里toolStripProgressBar1.Maximum要改
                toolStripProgressBar1.Maximum = max + 1;
                toolStripProgressBar1.Value = min;
                for (int i = min; i <= max; i++)
                {
                    int k = max - i;
                    host = mask + i.ToString();
                    ipadds = IPAddress.Parse(host);
                    //特别注明,如果线程中需要传参,一般,传1个参数,就用这个类,这个类参数必须是object的
                    ParameterizedThreadStart mypar = new ParameterizedThreadStart(PingIP);
                    //经测试发现及时使用线程数组,和使用单个线程差不多速度
                    //tr[k] = new Thread(mypar);
                    //tr[k].Start(ipadds);
                     Thread th = new Thread(mypar);
                    th.Start(ipadds);
                }
            }
        }
    }
}