C#使用套接字发送信息和端口扫描

最新推荐文章于 2025-04-01 19:45:00 发布

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最新推荐文章于 2025-04-01 19:45:00 发布

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文章标签： ubuntu visual studio c++

本文链接：https://blog.youkuaiyun.com/weixin_45654230/article/details/121522046

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本文详细介绍了使用C#实现HelloWorld、UDP套接字通信（包括服务器端和客户端）、Windows窗体应用程序中的TCP通信，以及单线程和多线程端口扫描。通过实例代码展示了如何在C#中进行网络交互和并发操作，最后提到了Wireshark抓包工具在C# UDP套接字中的应用。

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一、C#实现HelloWorld

1.创建新项目

2.写入代码

复制以下代码运行

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HelloWorldConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("第{0}行：hello cqjtu！重交物联2019级", (i + 1));
            }
            System.Console.ReadKey();

        }
    }
}

二、使用UDP套接字给其他电脑发送信息

服务器端代码：

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;

namespace UDP
{
    class Program
    {
        static void Main(string[] args)
        {
            int recv;
            byte[] data = new byte[1024];

            //得到本机IP，设置UDP端口号         
            IPEndPoint ip = new IPEndPoint(IPAddress.Any, 8001);
            Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

            //绑定网络地址并监听
            newsock.Bind(ip);

            Console.WriteLine("This is a Server, host name is {0}", Dns.GetHostName());

            //等待客户机连接
            Console.WriteLine("Waiting for a client");

            //得到客户机IP
            IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
            EndPoint Remote = (EndPoint)(sender);
            recv = newsock.ReceiveFrom(data, ref Remote);
            Console.WriteLine("Message received from {0}: ", Remote.ToString());
            Console.WriteLine(Encoding.UTF8.GetString(data, 0, recv));

            //客户机连接成功后，发送信息
            string welcome = "你好 ! ";

            //字符串与字节数组相互转换
            data = Encoding.UTF8.GetBytes(welcome);

            //发送信息
            newsock.SendTo(data, data.Length, SocketFlags.None, Remote);
            while (true)
            {
                data = new byte[1024];
                //接收信息
                recv = newsock.ReceiveFrom(data, ref Remote);
                Console.WriteLine(Encoding.UTF8.GetString(data, 0, recv));
                //newsock.SendTo(data, recv, SocketFlags.None, Remote);
            }
        }

    }
}

客户端代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;

namespace UDPClient
{
    class Program
    {
        static void Main(string[] args)
        {
            byte[] data = new byte[1024];
            string input, stringData;

            //构建TCP 服务器
            Console.WriteLine("This is a Client, host name is {0}", Dns.GetHostName());

            //设置服务IP（这个IP地址是服务器的IP），设置TCP端口号
            IPEndPoint ip = new IPEndPoint(IPAddress.Parse("192.168.139.1"), 8001);

            //定义网络类型，数据连接类型和网络协议UDP
            Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

            string welcome = "你好! ";
            data = Encoding.UTF8.GetBytes(welcome);
            server.SendTo(data, data.Length, SocketFlags.None, ip);
            IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
            EndPoint Remote = (EndPoint)sender;

            data = new byte[1024];
            //对于不存在的IP地址，加入此行代码后，可以在指定时间内解除阻塞模式限制
            int recv = server.ReceiveFrom(data, ref Remote);
            Console.WriteLine("Message received from {0}: ", Remote.ToString());
            Console.WriteLine(Encoding.UTF8.GetString(data, 0, recv));
            int i = 0;
            while (true)
            {
                string s = "hello cqjtu!重交物联2019级" + i;
                Console.WriteLine(s);
                server.SendTo(Encoding.UTF8.GetBytes(s), Remote);
                if (i == 50)
                {
                    break;
                }
                i++;
            }
            Console.WriteLine("Stopping Client.");
            server.Close();
        }

    }
}

先运行服务器端代码，等待客户端发送信息。接着运行客户端给服务器发送代码。

三、Form窗口程序发送

新建两个window窗体程序

一个服务器端，一个客户端

服务器界面：

服务器代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WinServer
{
    public partial class Form1 : Form
    {
        string str = "没有改变";
        public Form1()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string str = textBox1.Text;
            Console.WriteLine(str);
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(str);
            socketSend.Send(buffer);
        }
        void showMsg(string str)
        {
            textBox2.AppendText(str + "\r\n");
        }
        void Receive(Object o)
        {
            try
            {
                Socket socketSend = o as Socket;
                while (true)
                {
                    byte[] buffer = new byte[1024 * 1024 * 2];
                    int r = socketSend.Receive(buffer);
                    if (r == 0)
                    {
                        break;
                    }
                    string str = Encoding.UTF8.GetString(buffer, 0, r);
                    Invoke(new Action(() => {//在线程里修改界面
                        showMsg(socketSend.RemoteEndPoint + ":" + str);
                    }));
                }
            }
            catch
            { }
        }
        Socket socketSend;
        //等待客户端的连接
        void listen(Object o)
        {
            try
            {

                Socket socketwatch = o as Socket;
                int i = 0;
                while (true)
                {
                    //等待客户端的连接
                    socketSend = socketwatch.Accept();

                    str = socketSend.RemoteEndPoint.ToString() + ":" + "连接成功！";
                    Invoke(new Action(() => {//在线程里修改界面
                        showMsg(socketSend.RemoteEndPoint.ToString() + ":" + "连接成功！");
                    }));
                    Thread th = new Thread(Receive);
                    th.IsBackground = true;
                    th.Start(socketSend);
                }
            }
            catch
            { }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                //点击开始侦听的时候，服务器创建一个负责监听IP地址跟端口号的Socket
                Socket socketwatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                IPAddress ip = IPAddress.Any;
                //创建端口对象
                IPEndPoint point = new IPEndPoint(ip, 8001);
                //绑定
                socketwatch.Bind(point);

                showMsg("监听成功！");
                socketwatch.Listen(10);
                //创建一个线程
                Thread th = new Thread(listen);
                th.IsBackground = true;
                th.Start(socketwatch);

            }
            catch
            {
                showMsg("监听失败");
            }
        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {

        }
    }
}

客户端界面：

客户端代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WinClient
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        Socket socketSend;
        private void button1_Click(object sender, EventArgs e)
        {
            socketSend = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPEndPoint point = new IPEndPoint(IPAddress.Parse("192.168.56.1"), 8001);
            socketSend.Connect(point);
            showMsg("连接成功!");
            Thread th = new Thread(Receive);
            th.IsBackground = true;
            th.Start();
        }
        void Receive()
        {
            try
            {
                while (true)
                {
                    byte[] buffer = new byte[1024 * 1024 * 2];
                    int r = socketSend.Receive(buffer);
                    if (r == 0)
                    {
                        break;
                    }
                    string str = Encoding.UTF8.GetString(buffer, 0, r);
                    Invoke(new Action(() => {//在线程里修改界面
                        showMsg(socketSend.RemoteEndPoint + ":" + str);
                    }));
                }
            }
            catch
            { }
        }
        void showMsg(string str)
        {
            textBox2.AppendText(str + "\r\n");
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string str = textBox1.Text;
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(str);
            socketSend.Send(buffer);
        }
    }
}

服务器先开始监听，然后点击连接

，显示连接成功就可以开始互发消息了

四、单线程扫描

界面设计：

代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace dansaomiao
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        //自定义变量
        private int port;//记录当前扫描的端口号
        private string Address;//记录扫描的系统地址
        private bool[] done = new bool[65536];//记录端口的开放状态
        private int start;//记录扫描的起始端口
        private int end;//记录扫描的结束端口
        private bool OK;

        private void button1_Click(object sender, EventArgs e)
        {
            label2.Text = textBox3.Text;
            label3.Text = textBox4.Text;
            progressBar1.Minimum = Int32.Parse(textBox3.Text);
            progressBar1.Maximum = Int32.Parse(textBox4.Text);
            listBox1.Items.Clear();
            listBox1.Items.Add("端口扫描器v1.0.");
            listBox1.Items.Add("");
            PortScan();
        }

        private void PortScan()
        {
            start = Int32.Parse(textBox3.Text);
            end = Int32.Parse(textBox4.Text);
            //判断输入端口是否合法
            if ((start >= 0 && start <= 65536) && (end >= 0 && end <= 65536) && (start <= end))
            {
                listBox1.Items.Add("开始扫描：这个过程可能需要等待几分钟！");
                Address = textBox2.Text;
                for (int i = start; i <= end; i++)
                {
                    port = i;
                    Scan();
                    progressBar1.Value = i;
                    label2.Text = i.ToString();
                }
                while (!OK)
                {
                    OK = true;
                    for (int i = start; i <= end; i++)
                    {
                        if (!done[i])
                        {
                            OK = false;
                            break;
                        }
                    }
                }
                listBox1.Items.Add("扫描结束！");
            }
            else
            {
                MessageBox.Show("输入错误，端口范围为[0,65536]");
            }
        }

        private void Scan()
        {
            int portnow = port;
            done[portnow] = true;
            TcpClient objTCP = null;
            try
            {
                objTCP = new TcpClient(Address, portnow);
                listBox1.Items.Add("端口" + portnow.ToString() + "开放");
            }
            catch
            {

            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox5_TextChanged(object sender, EventArgs e)
        {

        }
    }
}

五、多线程扫描

界面设计：

代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace duosaomiao
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        //自定义变量
        private int port;//记录当前扫描的端口号
        private string Address;//记录扫描的系统地址
        private bool[] done = new bool[65536];//记录端口是否已经扫描
        private int start;//记录扫描的起始端口
        private int end;//记录扫描的结束端口
        private bool OK;
        private Thread scanThread;  

        private void Form1_Load(object sender, EventArgs e)
        {

        }
        private void label4_TextChanged(object sender, EventArgs e)
        {
            label4.Text = textBox2.Text;//设定进度条的起始端口
        }
        private void label6_TextChanged(object sender, EventArgs e)
        {
            label5.Text = textBox3.Text;//设置进度条的终止端口
        }

        private void button1_Click(object sender, EventArgs e)
        {
            label4_TextChanged(sender, e);
            label6_TextChanged(sender, e);
            //创建线程
            Thread procss = new Thread(new ThreadStart(PortScan));
            procss.Start();
            //设定进度条的范围
            progressBar1.Minimum = Int32.Parse(textBox2.Text);
            progressBar1.Maximum = Int32.Parse(textBox3.Text);
            //显示框的初始化
            listBox1.Items.Clear();
            listBox1.Items.Add("端口扫描器 v1.0");
            listBox1.Items.Add(" ");
        }

        private void PortScan()
        {
            start = Int32.Parse(textBox2.Text);
            end = Int32.Parse(textBox3.Text);
            //检查端口的合法性
            if ((start >= 0 && start <= 65536) && (end >= 0 && end <= 65536) && (start <= end))
            {

                Invoke(new Action(() => {//在线程里修改界面
                    listBox1.Items.Add("开始扫描：这个过程可能需要等待几分钟！");
                }));
                Address = textBox1.Text;
                for (int i = start; i <= end; i++)
                {
                    port = i;
                    //对该端口进行扫描的线程
                    scanThread = new Thread(Scan);
                    scanThread.Start();
                    //使线程睡眠
                    System.Threading.Thread.Sleep(100);

                    Invoke(new Action(() => {//在线程里修改界面
                        progressBar1.Value = i;
                        label5.Text = i.ToString();
                    }));
                }
                //未完成时情况
                while (!OK)
                {
                    OK = true;
                    for (int i = start; i <= end; i++)
                    {
                        if (!done[i])
                        {
                            OK = false;
                            break;
                        }
                    }
                }

                Invoke(new Action(() => {//在线程里修改界面
                    listBox1.Items.Add("扫描结束！");
                }));
                System.Threading.Thread.Sleep(1000);
            }
            else
            {
                Invoke(new Action(() => {//在线程里修改界面
                    MessageBox.Show("输入错误，端口范围为[0,65536]");
                }));

            }
        }

        private void Scan()
        {
            int portnow = port;
            //创建线程变量
            Thread Threadnow = scanThread;
            done[portnow] = true;
            //创建TcpClient对象，TcpClient用于TCP网络服务提供客户端连接
            TcpClient objTCP = null;
            //扫描端口，成功就写入信息
            try
            {
                objTCP = new TcpClient(Address, portnow);
                Invoke(new Action(() => {//在线程里修改界面
                    listBox1.Items.Add("端口" + portnow.ToString() + "开放！");
                }));
                objTCP.Close();
            }
            catch
            {

            }
        }

        private void progressBar1_Click(object sender, EventArgs e)
        {

        }
    }
}