using System;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace SingleThreadScanningPort
{
    public partial class Form1 : Form
    {
        
        private bool[] ports = new bool[65536];//所有端口號(hào)
        private static int port=0;//當(dāng)前端口號(hào)
        private static int count = 0;//開放端口號(hào)數(shù)量

        public Form1()
        {
            InitializeComponent();
            //CheckForIllegalCrossThreadCalls設(shè)置為false；然后就能安全的訪問窗體控件
            CheckForIllegalCrossThreadCalls = false;

            //初始化進(jìn)度顯示為空
            label2.Text = "";

            //停止掃描按鈕為不可用
            stopScanning.Enabled = false;
        }

        private void beginScanning_Click(object sender, EventArgs e)
        {
            //檢查端口號(hào)
            if (int.Parse(beginPortText.Text) < 0 || int.Parse(beginPortText.Text) > int.Parse(endPortText.Text) || int.Parse(endPortText.Text) > 65565)
            {
                messages.Items.Add("端口錯(cuò)誤!");
                return;
            }

            //新建線程執(zhí)行掃描端口函數(shù)
            Thread procss = new Thread(new ThreadStart(ScanningPort));
            procss.Start();

            //設(shè)置進(jìn)度條最大值最小值分別為結(jié)束端口和起始端口
            progressBar1.Maximum = int.Parse(endPortText.Text) - int.Parse(beginPortText.Text);
            progressBar1.Minimum = 0;

            //判斷是否為繼續(xù)掃描
            if (port == 0)
            {
                messages.Items.Clear();
                messages.Items.Add("開始掃描.......");
            }

            else
                messages.Items.Add("繼續(xù)掃描......");

            //開始掃描禁用,停止掃描啟用
            beginScanning.Enabled = false;
            stopScanning.Enabled = true;
        }
        public void ScanningPort()
        {
            int start;
            int end = int.Parse(endPortText.Text);

            //判斷是否為繼續(xù)掃描,如果是則繼續(xù)掃描,否則重新掃描
            if (port != 0)
                start = port;
            else
                start = int.Parse(beginPortText.Text);

            messages.Items.Add("起始端口" + start);
            messages.Items.Add("結(jié)束端口" + end);


            for (int i = start; i <= end; i++)
            {

                //按下停止掃描后開始掃描按鈕啟用,此時(shí)停止掃描
                if (beginScanning.Enabled)
                    break;
                port = i;

                //新建線程進(jìn)行掃描
                Thread thread = new Thread(Scanning);
                thread.Start();

                //主線程休眠10ms
                System.Threading.Thread.Sleep(10);

                //修改進(jìn)度條的值
                progressBar1.Value = i- int.Parse(beginPortText.Text);

                //顯示端口號(hào)以及進(jìn)度
                label2.Text = "正在掃描端口: " + i+"  進(jìn)度: "+Math.Round(( (i - int.Parse(beginPortText.Text)) *100.0 / progressBar1.Maximum),2)+"%";
                progressBar1.PerformStep();
            }

            if (port != 0)
                beginScanning.Text = "繼續(xù)掃描";
            else
            {
                messages.Items.Add("端口掃描結(jié)束");
                messages.Items.Add("共有 " + count + " 個(gè)端口開放");
            }

            beginScanning.Enabled = true;
            stopScanning.Enabled = false;
           

            //判斷是否掃描完畢
            if (int.Parse(endPortText.Text) == port)
            {
                port = 0;
                beginScanning.Text = "開始掃描";
            }

        }


        public void Scanning()
        {
            this.ports[port] = true;
            try
            {
                TcpClient tmp = new TcpClient(ipAddressText.Text, port);
                messages.Items.Add("端口" + port + "開放");
                count++;
            }

            catch (System.Exception ex)
            {
               
            }
        }

        private void stopScanning_Click(object sender, EventArgs e)
        {
            //按下停止按鈕后,開始按鈕和停止按鈕狀態(tài)翻轉(zhuǎn)
            beginScanning.Enabled = true;
            stopScanning.Enabled = false;
        }
    }
}

2.界面

在這里插入圖片描述

3.結(jié)果

由于是單線程執(zhí)行，在掃描端口的時(shí)候程序會(huì)直接卡死。所以只簡(jiǎn)單掃描幾個(gè)端口

在這里插入圖片描述

4.抓包

由于是通過以太網(wǎng)發(fā)送的，建議先注銷哆點(diǎn)再進(jìn)行抓包，減少數(shù)據(jù)。
可以發(fā)現(xiàn)3900端口成功實(shí)現(xiàn)三次握手，即該端口是開放的。而其他端口（紅色）則是無法建立連接，意味著是關(guān)閉的。

在這里插入圖片描述

二、多線程掃描

1.代碼

using System;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace SingleThreadScanningPort
{
    public partial class Form1 : Form
    {
        
        private bool[] ports = new bool[65536];//所有端口號(hào)
        private static int port=0;//當(dāng)前端口號(hào)
        private static int count = 0;//開放端口號(hào)數(shù)量

        public Form1()
        {
            InitializeComponent();
            //CheckForIllegalCrossThreadCalls設(shè)置為false；然后就能安全的訪問窗體控件
            CheckForIllegalCrossThreadCalls = false;

            //初始化進(jìn)度顯示為空
            label2.Text = "";

            //停止掃描按鈕為不可用
            stopScanning.Enabled = false;
        }

        private void beginScanning_Click(object sender, EventArgs e)
        {
            //檢查端口號(hào)
            if (int.Parse(beginPortText.Text) < 0 || int.Parse(beginPortText.Text) > int.Parse(endPortText.Text) || int.Parse(endPortText.Text) > 65565)
            {
                messages.Items.Add("端口錯(cuò)誤!");
                return;
            }

            //新建線程執(zhí)行掃描端口函數(shù)
            Thread procss = new Thread(new ThreadStart(ScanningPort));
            procss.Start();

            //設(shè)置進(jìn)度條最大值最小值分別為結(jié)束端口和起始端口
            progressBar1.Maximum = int.Parse(endPortText.Text) - int.Parse(beginPortText.Text);
            progressBar1.Minimum = 0;

            //判斷是否為繼續(xù)掃描
            if (port == 0)
            {
                messages.Items.Clear();
                messages.Items.Add("開始掃描.......");
            }

            else
                messages.Items.Add("繼續(xù)掃描......");

            //開始掃描禁用,停止掃描啟用
            beginScanning.Enabled = false;
            stopScanning.Enabled = true;
        }
        public void ScanningPort()
        {
            int start;
            int end = int.Parse(endPortText.Text);

            //判斷是否為繼續(xù)掃描,如果是則繼續(xù)掃描,否則重新掃描
            if (port != 0)
                start = port;
            else
                start = int.Parse(beginPortText.Text);

            messages.Items.Add("起始端口" + start);
            messages.Items.Add("結(jié)束端口" + end);


            for (int i = start; i <= end; i++)
            {

                //按下停止掃描后開始掃描按鈕啟用,此時(shí)停止掃描
                if (beginScanning.Enabled)
                    break;
                port = i;

                //新建線程進(jìn)行掃描
                Thread thread = new Thread(Scanning);
                thread.Start();

                //主線程休眠10ms
                System.Threading.Thread.Sleep(10);

                //修改進(jìn)度條的值
                progressBar1.Value = i- int.Parse(beginPortText.Text);

                //顯示端口號(hào)以及進(jìn)度
                label2.Text = "正在掃描端口: " + i+"  進(jìn)度: "+Math.Round(( (i - int.Parse(beginPortText.Text)) *100.0 / progressBar1.Maximum),2)+"%";
                progressBar1.PerformStep();
            }

            if (port != 0)
                beginScanning.Text = "繼續(xù)掃描";
            else
            {
                messages.Items.Add("端口掃描結(jié)束");
                messages.Items.Add("共有 " + count + " 個(gè)端口開放");
            }

            beginScanning.Enabled = true;
            stopScanning.Enabled = false;
           

            //判斷是否掃描完畢
            if (int.Parse(endPortText.Text) == port)
            {
                port = 0;
                beginScanning.Text = "開始掃描";
            }

        }


        public void Scanning()
        {
            this.ports[port] = true;
            try
            {
                TcpClient tmp = new TcpClient(ipAddressText.Text, port);
                messages.Items.Add("端口" + port + "開放");
                count++;
            }

            catch (System.Exception ex)
            {
               
            }
        }

        private void stopScanning_Click(object sender, EventArgs e)
        {
            //按下停止按鈕后,開始按鈕和停止按鈕狀態(tài)翻轉(zhuǎn)
            beginScanning.Enabled = true;
            stopScanning.Enabled = false;
        }
    }
}