c# 使用udp协议接收消息

@【】
两个例子

例一：
引用命名空间

using System.Net;
using System.Net.Sockets;

定义

 private UdpClient Reveive;
 IPAddress localIP = IPAddress.Parse(GetLocalIpv4()[0]);//获取本机ip地址,也可以自己手动填写
 IPEndPoint localIPEndPoint = new IPEndPoint(localIP, 8888);//设置ip和端口
 Reveive = new UdpClient(localIPEndPoint);
 //启动接收线程
 Thread threadReceive = new Thread(ReceiveMessages);//线程回调函数为ReceiveMessages
 threadReceive.IsBackground = true;
 threadReceive.Start();//开启

//获取本机IP

   		private string[] GetLocalIpv4()//获取本机ip
        {
            //事先不知道ip的个数，数组长度未知，因此用StringCollection储存  
            IPAddress[] localIPs;
            localIPs = Dns.GetHostAddresses(Dns.GetHostName());
            StringCollection IpCollection = new StringCollection();
            foreach (IPAddress ip in localIPs)
            {
                //根据AddressFamily判断是否为ipv4,如果是InterNetWorkV6则为ipv6  
                if (ip.AddressFamily == AddressFamily.InterNetwork)
                    IpCollection.Add(ip.ToString());
            }
            string[] IpArray = new string[IpCollection.Count];
            IpCollection.CopyTo(IpArray, 0);
            return IpArray;
        }

//线程回调函数

        private void ReceiveMessages()//线程回调函数
        {
            IPEndPoint remoteIPEndPoint = new IPEndPoint(IPAddress.Any, 0);
            while (true)
            {
                try
                {
                    byte[] receiveBytes = Reveive.Receive(ref remoteIPEndPoint);
                    string message = System.Text.Encoding.ASCII.GetString(receiveBytes, 0, receiveBytes.Length);
                    string[] date = message.Split('$');
                    Command = date[0];
                    switch (Command)
                    {
                        case "message1":
                             //收到消息：message1
                            break;
                        case "message2": 
                            //收到消息：message2
                            break;
                        default:                          
                            break;
                    }
                }
                catch (Exception e)
                {
                    break;
                }
            }
        }

试试能不能收到消息吧

脚本2：

using System.Collections;
//引入库
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using UnityEngine;

public class UDPClient : MonoBehaviour
{
    //以下默认都是私有的成员
    Socket socket; //目标socket
    EndPoint clientEnd; //客户端
    IPEndPoint ipEnd; //侦听端口
    string recvStr; //接收的字符串
    string sendStr; //发送的字符串
    byte[] recvData = new byte[1024]; //接收的数据，必须为字节
    byte[] sendData = new byte[1024]; //发送的数据，必须为字节
    int recvLen; //接收的数据长度
    Thread connectThread; //连接线程

    private void Start()
    {
        InitSocket();
    }
    void InitSocket()
    {
        //定义侦听端口,侦听任何IP
        ipEnd = new IPEndPoint(IPAddress.Any, 1232);
        //定义套接字类型,在主线程中定义
        socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        //服务端需要绑定ip
        socket.Bind(ipEnd);
        //定义客户端
        IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
        clientEnd = (EndPoint)sender;
        print("waiting for UDP dgram");

        //开启一个线程连接，必须的，否则主线程卡死
        connectThread = new Thread(new ThreadStart(SocketReceive));
        connectThread.Start();
        print("开始线程！");
    }
    void SocketSend(string sendStr)
    {
        print(sendStr);
    }
    //服务器接收
    void SocketReceive()
    {
        //进入接收循环
        while (true)
        {
            //对data清零
            recvData = new byte[1024];
            //获取客户端，获取客户端数据，用引用给客户端赋值
            recvLen = socket.ReceiveFrom(recvData, ref clientEnd);
            print("message from: " + clientEnd.ToString()); //打印客户端信息
                                                            //输出接收到的数据
            recvStr = Encoding.ASCII.GetString(recvData, 0, recvLen);
            print("我是服务器，接收到客户端的数据" + recvStr);
            //将接收到的数据经过处理再发送出去
            sendStr = "From Server: " + recvStr;
            SocketSend(sendStr);

            print("接收！");
        }
    }


    //连接关闭
    void SocketQuit()
    {
        //关闭线程
        if (connectThread != null)
        {
            connectThread.Interrupt();
            connectThread.Abort();
        }
        //最后关闭socket
        if (socket != null)
            socket.Close();
        print("disconnect");
    }
    void OnDestroy()
    {
        SocketQuit();
    }
}

小结：socket通信中的UDP、TCP还有串口通信的使用方法都大致相似，本文中只讲了应用，具体详细的解析后边我会继续完善，文中若有不足或错误请直接指出，欢迎评论交流。

学习入口：

1. C#串口通信
2. C#获取桌面路径
3. C#串口通信中 16进制与字符串、字节数组之间的转换