这些方法是对socket的一些封装，用法基本和原本用法一样。

Tcp服务端

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Net;
using System.Net.Sockets;

namespace Lesson1
{
    class Program
    {
        static void Main(string[] args)
        {
            string ip = "127.0.0.1";
            int port = 2333;
            IPAddress address = IPAddress.Parse(ip);
            //1.对socket进行了一层封装，这个类自动创建socket对象
            TcpListener listener = new TcpListener(address, port);
            //2.开始监听
            listener.Start();
            Console.WriteLine("服务器开始侦听");

            while (true)
            {
                //3.等待客户端连接过来
                TcpClient client = listener.AcceptTcpClient();//阻塞获取客户端连接

                //把client交给SocketClien类，开启新线程读取数据
                SocketClient socket = new SocketClient(client);
            }

        }

    }
    class SocketClient
    {
        const int BufferSize = 8192;//定义buffer缓冲区长度
        byte[] buffer = new byte[BufferSize];

        TcpClient client;
        NetworkStream stream;

        public SocketClient(TcpClient _client)
        {
            client = _client;
            Console.WriteLine("客户端连接成功：" + client.Client.RemoteEndPoint);
            //4.取得客户端发送过来的数据
            stream = client.GetStream();//获取网络流，这个网络流可以取得客户端发来的数据

            //while (true)
            //{
            //    int readCount = stream.Read(buffer, 0, BufferSize);//阻塞读取网络流
            //    string msg = Encoding.UTF8.GetString(buffer, 0, readCount);
            //    Console.WriteLine("接收到" + client.Client.RemoteEndPoint + "的消息：" + msg);
            //}

            //开启异步读取数据
            stream.BeginRead(buffer, 0, BufferSize, Read, null);
        }

        //子线程读取消息
        void Read(IAsyncResult ar)
        {
            try
            {
                int readCount = stream.EndRead(ar);
                string msg = Encoding.UTF8.GetString(buffer, 0, readCount);
                Console.WriteLine("接收到客户端:" + client.Client.RemoteEndPoint + "的消息：" + msg);

                lock (client) //线程锁，解决互斥(资源不共享)问题
                {
                    Array.Clear(buffer, 0, BufferSize); //清除缓冲区
                    stream.BeginRead(buffer, 0, BufferSize, Read, null);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }

        }
    }
}

Tcp客户端

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

namespace Lesson2
{
    class Program
    {
        static void Main(string[] args)
        {
            //新建客户端连接
            SocketClient client = new SocketClient();

            while (true)
            {
                Console.WriteLine("请输入消息：");
                string msg = Console.ReadLine();

                client.Send(msg);
            }

        }
    }
    class SocketClient
    {
        string ip = "127.0.0.1";
        int port = 8500;
        TcpClient client;
        NetworkStream stream;
        const int BufferSize = 8192;
        byte[] buffer = new byte[BufferSize];

        public SocketClient()
        {
            client = new TcpClient();
            client.Connect(ip, port);//连接服务器
            Console.WriteLine("连接上服务器:" + client.Client.RemoteEndPoint);

            stream = client.GetStream();//获取网络流
            //开启异步读取数据
            stream.BeginRead(buffer, 0, BufferSize, Read, null);
        }

        //子线程读取消息
        void Read(IAsyncResult ar)
        {
            try
            {
                int readCount = stream.EndRead(ar);
                string msg = Encoding.UTF8.GetString(buffer, 0, readCount);
                Console.WriteLine("接收到客户端:" + client.Client.RemoteEndPoint + "的消息：" + msg);

                lock (client)
                {
                    Array.Clear(buffer, 0, BufferSize);
                    stream.BeginRead(buffer, 0, BufferSize, Read, null);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        //往流里面写入==给服务器发消息
        void Write(string msg)
        {
            byte[] bytes = Encoding.UTF8.GetBytes(msg);
            //write用来写入数据，和Send基本一样，Send不用控制长度
            stream.Write(bytes, 0, bytes.Length);
        }

        //向服务器发送消息
        public void Send(string msg)
        {
            Write(msg);
        }
    }
}

UDP服务端(udp协议不需要连接，所以只有一个UdpClient)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Net;
using System.Net.Sockets;

namespace Lesson1
{
    class Program
    {
        static void Main(string[] args)
        {
            //1.创建udpclient并绑定端口号
            UdpClient udpClient = new UdpClient(new IPEndPoint(IPAddress.Parse("127.0.0.1"), 2333));
            //2.接收数据
            while (true)
            {
                IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, 0);
                byte[] data = udpClient.Receive(ref endPoint);//ref获取时哪个ip传过来的,返回一个字节数组就是我们的数据
                string msg = Encoding.UTF8.GetString(data);
            }
           

        }

    }

}

UDP客户端

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

namespace Lesson2
{
    class Program
    {
        static void Main(string[] args)
        {
            //1.创建udpclient并绑定端口号
            UdpClient udpClient = new UdpClient();
            //2.发送数据
            while (true)
            {
                string msg = Console.ReadLine();
                byte[] data = Encoding.UTF8.GetBytes(msg);
                udpClient.Send(data, data.Length, new IPEndPoint(IPAddress.Parse("127.0.0.1"), 2333));//第三个参数表示要发送到的地方
            }
            
        }
    }
   
}