C# 使用UDP进行网络通信

   在选择使用协议的时候，选择UDP必须要谨慎。在网络质量令人十分不满意的环境下，UDP协议数据包丢失会比较严重。但是由于UDP的特性:它不属于连接型协议，因而具有资源消耗小，处理速度快的优点，所以通常音频、视频和普通数据在传送时使用UDP较多，因为它们即使偶尔丢失一两个数据包，也不会对接收结果产生太大影响。比如我们聊天用的ICQ和QQ就是使用的UDP协议。

服务端代码

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

namespace UDP服务器
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            CheckForIllegalCrossThreadCalls = false;
            InitializeComponent();
            textBox1.Text = "127.0.0.1";
            textBox2.Text = "8401";
        }
        /// <summary>
        /// 获取本地IP
        /// </summary>
        private void label1_Click(object sender, EventArgs e)
        {
            string ip = IPAddress.Any.ToString();
            textBox1.Text = ip;
        }

        Socket server;
        private void button2_Click(object sender, EventArgs e)
        {

            server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            server.Bind(new IPEndPoint(IPAddress.Parse(textBox1.Text), int.Parse(textBox2.Text)));//绑定端口号和IP
            //server.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);
            listBox1.Items.Add("服务器已经成功开启!");
            //开启接收消息线程
            Thread t = new Thread(ReciveMsg);
            t.IsBackground = true;
            t.Start();
        }
        /// <summary>
        /// 向特定ip的主机的端口发送数据
        /// </summary>te
        void SendMsg()
        {
            EndPoint point = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8400);    //向指定的IP和端口发送消息
            string msg = textBox3.Text;
            server.SendTo(Encoding.UTF8.GetBytes(msg), point);
        }

        /// <summary>
        /// 接收发送给本机ip对应端口号的数据
        /// </summary>
        void ReciveMsg()
        {
            while (true)
            {
                EndPoint point = new IPEndPoint(IPAddress.Any, 0);//用来保存发送方的ip和端口号
                byte[] buffer = new byte[1024 * 1024];
                int length = server.ReceiveFrom(buffer, ref point);//接收数据报
                string message = Encoding.UTF8.GetString(buffer, 0, length);
                listBox1.Items.Add(point.ToString() + "：" + message);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (textBox3.Text != "")
            {
                //开启发送消息线程
                Thread t3 = new Thread(SendMsg);
                t3.Start();
                listBox1.Items.Add(textBox1.Text + "：" + textBox2.Text + "：" + textBox3.Text);
            }

        }

    }
}

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

namespace UDP客户端
{
    public partial class Form1 : Form
    {

        public Form1()
        {
            CheckForIllegalCrossThreadCalls = false;
            InitializeComponent();
            textBox1.Text = "127.0.0.1";
            textBox2.Text = "8400";
        }
        /// <summary>
        /// 创建客户端
        /// </summary>
        Socket client;

        private void button2_Click(object sender, EventArgs e)
        {
            
           

            ///创建客户端
            client = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            client.Bind(new IPEndPoint(IPAddress.Parse(textBox1.Text), int.Parse(textBox2.Text)));
            ///线程问题
            Thread thread = new Thread(ReciveMsg);
            thread.IsBackground = true;
            thread.Start(client);
            listBox1.Items.Add("客户端已成功开启!");
        }

        /// <summary>
        /// 向特定ip的主机的端口发送数据
        /// </summary>
        void SendMsg()
        {
            EndPoint point = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8401);    //向指定的IP和端口发送消息
            ///发送内容
            string msg = textBox3.Text;
            ///将数据发送到指定的ip的主机的端口
            client.SendTo(Encoding.UTF8.GetBytes(msg), point);
        }
        /// <summary>
        /// 接收发送给本机ip对应端口号的数据
        /// </summary>
        void ReciveMsg(object o)
        {

            while (true)
            {
                try
                {
                    ///用来保存发送方的ip和端口号
                    EndPoint point = new IPEndPoint(IPAddress.Any, 0);
                    //MessageBox.Show(point.ToString());
                    ///定义客户端接收到的信息大小
                    byte[] buffer = new byte[1024 * 1024];
                    ///接收到的信息大小(所占字节数)
                    int length = client.ReceiveFrom(buffer, ref point);
                    string message = Encoding.UTF8.GetString(buffer, 0, length);
                    listBox1.Items.Add(point.ToString() + "：" + message);
                }
                catch (Exception)
                {
                    client.Close();
                }

            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (textBox3.Text != "")
            {
                //开启发送消息线程
                Thread t2 = new Thread(SendMsg);
                t2.Start();
                listBox1.Items.Add(textBox1.Text + "：" + textBox2.Text + ":" + textBox3.Text);
            }

        }
    }
}

效果展示

代码下载地址：

链接：https://pan.baidu.com/s/1r-V80I5fJ-8noF8YgMOlLA
提取码：qx3s