二维码配网 (Two-dimensional code distribution network)

1.在进行二维码配网时需要Android设备连接一个非5G并可连通外网的WIFI。(When performing the two-dimensional code distribution network, the Android device needs to connect to a WIFI that is not 5G and can be connected to the external network.)

2.APP端检测是否打开定位权限获取WIFI名称，用户输入WIFI密码，获取到WIFI名称以及密码后保存进入下一步。(The APP detects whether the privilege is enabled to obtain the WIFI name. The user enters the WIFI password, obtains the WIFI name and password, and saves the next step.)

3.拼接生成二维码需要的字符串 (Stitching the string needed to generate the QR code)

String wifiString = new StringBuilder()
                .append("S=").append(ssid).append(",")// wifi 名称 (Wifi name)
                .append("P=").append(pwd).append(",") // wifi 密码 (Wifi Password)
                .append("A=").append("15111520684").append(",")//任意字符串或者用户app账号 (Any string or user app account)
                .append("U=").append("abc").append(",")//填一个任意字符串 (Fill in an arbitrary string)
                .append("T=").append(wifiType)
                .toString();
Bitmap mBitmap = CodeUtils.createImage(wifiString, width, width, null);
ivQRcode.setImageBitmap(mBitmap);

4.打开组播准备接收设备发出的配网成功消息，收到消息即视为连接成功。（注：设备连接成功后会多次发出组播消息） (The multicast success message sent by the multicast preparation device is opened. If the message is received, the connection is considered successful. (Note: Multicast messages will be sent multiple times after the device is successfully connected))

  String groupHost = "224.0.1.2";  //组播组虚拟IP (Multicast group virtual IP)
  int port = 6008;  //端口 (Port)

  String recieveData() {
        String message = "";
        try {
            byte[] data = new byte[512];
            DatagramPacket packet=new DatagramPacket(data, data.length,inetAddress,port);
            multicastSocket.receive(packet); // 通过MulticastSocket实例端口从组播组接收数据 (Receive data from a multicast group through the multicast socket instance port.)
            // 将接受的数据转换成字符串形式 (Convert accepted data to a string)
            message = new String(packet.getData(),0,packet.getLength());
        } catch (Exception e1) {
            System.out.println("Error: " + e1); // 捕捉异常情况 (Capturing anomalies)
            message = "Error: " + e1;
        }
        return message;
    }