python Android udp通信

python发送：

参考：https://www.cnblogs.com/reader/p/10011666.html

# -*- coding:utf-8 -*-

from socket import *
from time import ctime, sleep
import threading


class ChatRoomPlus:
    def __init__(self):
        # 全局参数配置
        self.encoding = "utf-8"  # 使用的编码方式
        self.broadcastPort = 22222   # 广播端口

        # 创建广播接收器
        self.recvSocket = socket(AF_INET, SOCK_DGRAM)
        self.recvSocket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
        self.recvSocket.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)
        self.recvSocket.bind(('', self.broadcastPort))

        # 创建广播发送器
        self.sendSocket = socket(AF_INET, SOCK_DGRAM)
        self.sendSocket.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)

        # 其他
        self.threads = []

    def send(self):
        """发送广播"""

        print("UDP发送器启动成功...")
        while True:
            sendData="hello123"
            self.sendSocket.sendto(sendData.encode(self.encoding), ('255.255.255.255', self.broadcastPort))
            print("【%s】%s:%s" % (ctime(), "我", sendData))

            sleep(1)
        self.sendSocket.close()

    def recv(self):
        """接收广播"""

        print("UDP接收器启动成功...")
        while True:
            # 接收数据格式：(data, (ip, port))
            recvData = self.recvSocket.recvfrom(1024)

            print("【%s】[%s : %s] : %s" % (ctime(), recvData[1][0], recvData[1][1], recvData[0].decode(self.encoding)))

            sleep(1)

    def start(self):
        """启动线程"""

        # t1 = threading.Thread(target=self.recv)
        t2 = threading.Thread(target=self.send)
        # self.threads.append(t1)
        self.threads.append(t2)

        for t in self.threads:
            t.setDaemon(True)
            t.start()

        while True:
            pass


if __name__ == "__main__":
    demo = ChatRoomPlus()
    demo.start()

Android接收：

参考：https://blog.csdn.net/aino0613/article/details/73087313

需要先在AndroidManifest.xml添加权限

<uses-permission android:name="android.permission.INTERNET" />

   private DatagramSocket msocketClient;
    private DatagramPacket Packet_Receive;
    private String ip;
    private String Port;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        et1 = findViewById(R.id.EditText02); 
        Open();
    }

    public void Open() {
        System.out.println("***start***");
        try {
            msocketClient = new DatagramSocket(null);
            msocketClient.setReuseAddress(true);
            msocketClient.bind(new InetSocketAddress(22222));
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (msocketClient != null) {
            new Thread(UdpReceiver).start();
        }
    }

    Runnable UdpReceiver = new Runnable() {
        @Override
        public void run() {
            WifiManager mwifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
            WifiManager.MulticastLock lock= mwifiManager.createMulticastLock("UDPwifi");
            while (true) {
//                System.out.println("***UdpReceiver***");
                byte[] Buffer_Receive = new byte[1024];
                Packet_Receive = new DatagramPacket(Buffer_Receive, 1024);
                if (Packet_Receive != null) {
                    try {
                        lock.acquire();
                        msocketClient.receive(Packet_Receive);
                        int length = Packet_Receive.getLength();
                        if (length > 0) {
                            final String data = new String(Buffer_Receive, 0, Packet_Receive.getLength());
//                            System.out.println("***data***"+data);
                            ip=""+Packet_Receive.getAddress();
                            Port=""+data;
//                            System.out.println("ip : "+Packet_Receive.getAddress()+"port :"+Packet_Receive.getPort());
                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    et1.setText("已连接"+ip+":"+Port);
                                }
                            });
                        }
                        lock.release();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    };

Android手机和电脑（运行python程序）必须在同一网络下（比如同一wifi），否则连接不上。即使手机连接的是电脑发射的热点wifi都不可以。或者使用电脑里的Android模拟机也连接不上。

参考：https://blog.csdn.net/ns_code/article/details/13094375

https://blog.csdn.net/qq_26075861/article/details/78361363