在Android 10中，应用程序默认无法接收UDP广播。以下是一种解决方法：

1. 在AndroidManifest.xml文件中添加以下权限：

2. 创建一个BroadcastReceiver类来接收UDP广播消息：

public class UdpBroadcastReceiver extends BroadcastReceiver {
    private static final String TAG = "UdpBroadcastReceiver";
    private static final int BUFFER_SIZE = 1024;

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action != null && action.equals("android.intent.action.udp_broadcast")) {
            byte[] buffer = new byte[BUFFER_SIZE];
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
            try (DatagramSocket socket = new DatagramSocket(12345)) {
                socket.receive(packet);
                String message = new String(packet.getData(), 0, packet.getLength());
                Log.d(TAG, "Received UDP broadcast: " + message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

3. 在你的Activity或Service中注册广播接收器和相应的过滤器：

public class MainActivity extends AppCompatActivity {
    private UdpBroadcastReceiver udpBroadcastReceiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        udpBroadcastReceiver = new UdpBroadcastReceiver();
        IntentFilter filter = new IntentFilter();
        filter.addAction("android.intent.action.udp_broadcast");
        registerReceiver(udpBroadcastReceiver, filter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(udpBroadcastReceiver);
    }
}

4. 确保在发送UDP广播消息时使用正确的IP地址和端口号。

请注意，这只是一种解决方法，并不保证适用于所有情况。在某些情况下，可能需要进一步调整网络配置或使用其他方法来实现UDP广播接收。