基于UDP、TCP协议的C#网络编程

public partial class Form2 : Form
    {

        //声明监听对象
        private TcpListener tl;

        //声明网络流
        private NetworkStream ns;
        public Form1()
        {
            CheckForIllegalCrossThreadCalls = false;
            InitializeComponent();           
        }

        private void btnStart_Click(object sender, EventArgs e)
        {

            //开启8888端口的监听
            tl = new TcpListener(8888);
            tl.Start();

            //开启线程
            Thread th = new Thread(new ThreadStart(listen));
            th.IsBackground = true;
            th.Start();
        }
        private void listen()
        {           
            while (true)
            {   

                //获得响应的Socket
                Socket sock = tl.AcceptSocket();  

                //通过该Socket实例化网络流           
                ns = new NetworkStream(sock);

                //ClientTcp是添加的类，下面会做说明
                ClientTcp ct = new ClientTcp(ns);

                //ct_MyEvent方法注册ClientTcp类的MyEvent事件
                ct.MyEvent += new MyDelegate(ct_MyEvent);

                //开启线程
                Thread th = new Thread(new ThreadStart(ct.TcpThread));
                th.IsBackground = true;
                th.Start();
            }
        }

        void ct_MyEvent(string temp)
        {

            //设置服务器端TextBox的值
            this.textBox1.Text = temp;
        }
    }

public partial class Form1 : Form
    {

        //声明Tcp客户端
        private TcpClient tc;

        //声明网络流
        private NetworkStream ns;
        public Form1()
        {
            CheckForIllegalCrossThreadCalls = false;
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {

            //注册本机8888端口
            tc = new TcpClient("localhost",8888);

            //实例化网络流对象
            ns = tc.GetStream();
            string temp = this.textBox1.Text;

            StreamWriter sw = new StreamWriter(ns);
            StreamReader sr = new StreamReader(ns);

            //将TextBox1的值传给服务器端
            sw.WriteLine(temp);
            sw.Flush();

            //接收服务器端回传的字符串
            string str = sr.ReadLine();
            this.textBox2.Text = str;
            sr.Close();
            sw.Close();
        }
    }

    //声明一个需要一个字符串参数的委托

    public delegate void MyDelegate(string temp);
    class ClientTcp
    {

        //设置网络流局部对象
        private NetworkStream ns;

        //声明类型为MyDelegate的事件MyEvent
        public event MyDelegate MyEvent;

        //构造函数中接收参数以初始化
        public ClientTcp(NetworkStream ns)
        {
            this.ns = ns;
        }

        //服务器端线程所调用的方法
        public void TcpThread()
        {

            //获得相关的封装流
            StreamReader sr = new StreamReader(ns);
            string temp = sr.ReadLine();

            //接收到客户端消息后触发事件将消息回传
            MyEvent(temp);
            StreamWriter sw = new StreamWriter(ns);

            //转换为大写后发送消息给客户端
            sw.WriteLine(temp.ToUpper());
            sw.Flush();
            sw.Close();
            sr.Close();
        }
    }