C# TCP通信

一、服务端

using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApp7
{
    public partial class Form2 : Form
    {
        //服务器套接字
        private Socket socket;
        //客户端连接
        List<Socket> sockets = new List<Socket>();

        Encoding encoding = Encoding.UTF8;
        public Form2()
        {
            InitializeComponent();
            load();
        }

        private void Label3_Click(object sender, EventArgs e)
        {

        }

        /// <summary>
        /// 加载
        /// </summary>
        private void load()
        {
            //1.获取本地网络分配给你的IP
            System.Net.IPHostEntry hostEntry = Dns.GetHostEntry(Dns.GetHostName());
            //第二步：
            foreach (var item in hostEntry.AddressList)
            {
                //3.判断是否是协议版本V4
                if (item.AddressFamily == AddressFamily.InterNetwork)
                {
                    cB_IPs.Items.Add(item);
                }
            }
            //添加本机IP
            cB_IPs.Items.Add("127.0.0.1");
            cB_IPs.Items.Add("192.168.110.96");
            cB_IPs.SelectedIndex = 0;//默认选中0个对象
        }

        /// <summary>
        /// 打开服务器
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button2_Click(object sender, EventArgs e)
        {
            //1.初始化
            socket = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
            //2.监听
            IPEndPoint iPEndPoint = new IPEndPoint(IPAddress.Parse(cB_IPs.Text) ,(int)numericUpDown1.Value);
            try
            {
                socket.Bind(iPEndPoint);//监听
                socket.Listen(10);//一秒可以监听多少个客户端连接
                //监听客户端
                ThreadPool.QueueUserWorkItem((Object o) =>
                {
                   
                    while (true)
                    {
                        Socket socket1 = socket.Accept();//客户端连接
                        sockets.Add(socket1);
                        //获取客户端连接IP和端口
                        IPEndPoint iPEndPoint1 = (IPEndPoint)socket1.RemoteEndPoint;
                        //显示到数据表格
                        dataGridView1.Invoke(new Action(() =>
                        {
                            dataGridView1.Rows.Add(iPEndPoint1.Address, iPEndPoint1.Port);
                        }));
                    }
                    
                });
            }
            catch (Exception ex)
            {
                MessageBox.Show($"服务端开始失败:{ex}");
            }

        }

        /// <summary>
        /// 发送
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button3_Click(object sender, EventArgs e)
        {
            try
            {
                //判断是否群发
                int index = dataGridView1.CurrentCell.RowIndex;
                //判断是否群发
                if (checkBox1.Checked)
                {
                    foreach (Socket item in sockets)
                    {
                        item.Send(encoding.GetBytes(textBox3.Text));
                    }
                }
                else
                {
                    //获取客户端socket
                    Socket socket = sockets[index];
                    //发送
                    socket.Send(encoding.GetBytes(textBox3.Text));
                }
            }
            catch (Exception ex)
            {

                MessageBox.Show($"发送失败:{ex}");
            }
      
        }
    }
}

二、客户端

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Windows.Forms;

namespace WindowsFormsApp7
{
    public partial class Form1 : Form
    {
        private Socket socket;
        Encoding encoding = Encoding.Unicode;
        public Form1()
        {
            InitializeComponent();
            load();

        }

        /// <summary>
        /// 加载
        /// </summary>
        private void load()
        {
            //1.获取本地网络分配给你的IP
            IPHostEntry hostEntry = Dns.GetHostEntry(Dns.GetHostName());
            //第二步：
            foreach (var item in hostEntry.AddressList)
            {
                //3.判断是否是协议版本V4
                if (item.AddressFamily == AddressFamily.InterNetwork)
                {
                    cB_IPs.Items.Add(item);
                }
            }
            //添加本机IP
            cB_IPs.Items.Add("127.0.0.1");
            cB_IPs.Items.Add("192.168.110.96");
            cB_IPs.SelectedIndex = 0;//默认选中0个对象
        }

        /// <summary>
        /// 连接
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button2_Click(object sender, EventArgs e)
        {
            //第一步：初始化套接字对象
            socket = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
            try
            {
                //第二步：连接
                socket.Connect(cB_IPs.Text,(int)numericUpDown1.Value);
                ThreadPool.QueueUserWorkItem(Reception);
                MessageBox.Show("连接成功！");
                button1.Enabled = true;
                button3.Enabled = true;
                button2.Enabled = false;
                cB_IPs.Enabled = false;
                numericUpDown1.Enabled = false;
            }
            catch(Exception ex)
            {
                //连接失败
                MessageBox.Show($"连接失败：{ex}");
            }

        }
        /// <summary>
        /// 断开
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button1_Click(object sender, EventArgs e)
        {
            if (socket != null && socket.Connected)
            {
                socket.Close();
                MessageBox.Show("断开连接");
                button1.Enabled = false;
                button2.Enabled = true;
                cB_IPs.Enabled = true;
                numericUpDown1.Enabled = true;
                button3.Enabled = false;
            }
        }

        /// <summary>
        /// 发送
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Button3_Click(object sender, EventArgs e)
        {
            //1.判断连接状态
            if (socket != null && socket.Connected)
            {
                //2.字符串转换二进制
                byte[] data = encoding.GetBytes(textBox3.Text);
                try
                {
                    //3.发送
                    socket.Send(data);
                }
                catch (Exception ex)
                {

                    MessageBox.Show($"发送失败：{ex}");
                }
            }
        }

        /// <summary>
        /// 接收数据
        /// </summary>
        public void Reception(Object o)
        {
            byte[] data = new byte[1024*2];
            try
            {
                //接收
                int length = socket.Receive(data);
                //判断是否有发送字节
                if (length > 0)
                {
                    textBox2.Invoke(new Action(() => {
                        textBox2.Text += $"RX [{DateTime.Now.ToString("HH:mm:ss")}]:{encoding.GetString(data, 0, length)}";
                    }));

                }
            }
            catch (Exception ex)
            {
                MessageBox.Show($"接收失败：{ex}");
            }
        }
    }
}