c# 扫描端口

//===========================================================
//   C# 实现端口扫描
//===========================================================
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;

using System.Threading;

namespace ConsoleApplication3
{
    class Program
    {
        //已扫描端口数目
        internal static int scannedCount = 0;

        internal static int runningThreadCount = 0;

        internal static List<int> openedPorts = new List<int>();

        static int startPort = 1;
        static int endPort = 500;

        static int maxThread = 100;

        
        static void Main(string[] args)
        {
            //简单提示
            Console.WriteLine("////////////////////////////////////////////////////////////////////////////////////");
            Console.WriteLine("//  Writer;Feeling");
            Console.WriteLine("////////////////////////////////////////////////////////////////////////////////////");
            Console.WriteLine("请输入要扫描的主机；");
            string host = Console.ReadLine();
            Console.WriteLine("请输入扫描的端口 例如：1-800");
            string portRange =Console.ReadLine();
            startPort = int.Parse(portRange.Split('-')[0].Trim());
            endPort = int.Parse(portRange.Split('-')[1].Trim());

            for (int port = startPort; port < endPort; port++)
            {
                Scanner scanner = new Scanner(host, port);
                Thread thread = new Thread(new ThreadStart(scanner.Scan));
                thread.Name = port.ToString();
                thread.IsBackground = true;
                thread.Start();

                runningThreadCount++;
                Thread.Sleep(10);

                //循环，直到某个线程工作完毕才启动另一新线程，也可以叫做推拉窗技术
                while (runningThreadCount >= maxThread) ;
            }
               //空循环，直到所有端口扫描完毕
          　  　while (scannedCount + 1 < (endPort - startPort)) ;
              Console.WriteLine();
              Console.WriteLine();

             //输出结果
              Console.WriteLine("Scan for host:{0} has been completed, \n total {1} ports scanned, \n opened ports:{2}", host, (endPort - startPort), openedPorts.Count);

              foreach (int port in openedPorts)
              {
                  Console.WriteLine("\tport: {0} is open", port.ToString().PadLeft(6));  
              }

              Console.ReadLine();
             
        }
    }

    class Scanner
    {
        string m_host;
        int m_port;

        public Scanner(string host, int port)
        {
            m_host = host;
            m_port = port;
        }
        public void Scan()
        {
            TcpClient tc = new TcpClient();
            tc.SendTimeout = tc.ReceiveTimeout = 2000;

            try
            {
                tc.Connect(m_host, m_port);
                if (tc.Connected)
                {
                    Console.WriteLine("Port {0} is Open", m_port.ToString().PadRight(6));
                    Program.openedPorts.Add(m_port);
                }
            }
            catch
            {
                Console.WriteLine("Port {0} is Closed", m_port.ToString().PadRight(6));
            }
            finally
            {
                tc.Close();
                tc = null;
                Program.scannedCount++;
                Program.runningThreadCount--;
            }
        }

    }
}

源自:http://www.cnblogs.com/luozhai714/archive/2008/02/21/1076181.html