Android 10 device doesn't start discovery of wifi direct

Question

I'm currently developing my own App which should send messages via WiFi Direct to other devices which are connected. On Android 9 and lower the discovery of the devices is starting successfully, but on Android 10 it isn't. This is my MainActivity.java file:

package com.shuzo.musicshare;

import android.Manifest;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pConfig;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pDeviceList;
import android.net.wifi.p2p.WifiP2pInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.StrictMode;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Switch;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    Button btnDiscover, btnSend;
    Switch switchOnOff;
    ListView listView;
    TextView readMsgBox, connectionStatus;
    EditText writeMsg;
    WifiManager wifiManager;
    WifiP2pManager mManager;
    WifiP2pManager.Channel mChannel;
    BroadcastReceiver mReceiver;
    IntentFilter mIntentFilter;
    List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
    String[] deviceNameArray;
    WifiP2pDevice[] deviceArray;
    static final int MESSAGE_READ = 1;
    ServerClass serverClass;
    List<ClientClass> clientClass = new ArrayList<>();
    SendReceive sendReceive;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
        initialWork();
        exqListener();
    }

    Handler handler = new Handler(new Handler.Callback() {
        @Override
        public boolean handleMessage(Message msg) {
            switch (msg.what) {
                case MESSAGE_READ:
                    byte[] readBuff = (byte[]) msg.obj;
                    String tempMsg = new String(readBuff, 0, msg.arg1);
                    readMsgBox.setText(tempMsg);
                    break;
            }
            return true;
        }
    });

    private void exqListener() {
        switchOnOff.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                wifiManager.setWifiEnabled(b);
            }
        });

        btnDiscover.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
                    @Override
                    public void onSuccess() {
                        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_DENIED) {
                            ActivityCompat.requestPermissions(MainActivity.this, new String[] { Manifest.permission.ACCESS_COARSE_LOCATION },1);
                        }
                        connectionStatus.setText("Discovery started");
                    }

                    @Override
                    public void onFailure(int i) {
                        connectionStatus.setText("Discovery starting failed");
                    }
                });
            }
        });

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                final WifiP2pDevice device = deviceArray[i];
                WifiP2pConfig config = new WifiP2pConfig();
                config.deviceAddress = device.deviceAddress;

                mManager.connect(mChannel, config, new WifiP2pManager.ActionListener() {
                    @Override
                    public void onSuccess() {
                        Toast.makeText(getApplicationContext(), "Connected to " + device.deviceName, Toast.LENGTH_SHORT).show();
                    }

                    @Override
                    public void onFailure(int i) {
                        Toast.makeText(getApplicationContext(), "Not Connected", Toast.LENGTH_SHORT).show();
                    }
                });
            }
        });

        btnSend.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String msg=writeMsg.getText().toString();
                sendReceive.write(msg.getBytes());
            }
        });
    }

    private void initialWork() {
        btnDiscover = findViewById(R.id.discover);
        btnSend = findViewById(R.id.sendButton);
        switchOnOff = findViewById(R.id.switchOnOff);
        wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        switchOnOff.setChecked(wifiManager.isWifiEnabled());
        listView = findViewById(R.id.peerListView);
        readMsgBox = findViewById(R.id.readMsg);
        connectionStatus = findViewById(R.id.connectionStatus);
        writeMsg = findViewById(R.id.writeMsg);
        mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
        mChannel = mManager.initialize(this, getMainLooper(), null);
        mReceiver = new WiFiDirectBroadcastReceiver(mManager, mChannel, this);
        mIntentFilter = new IntentFilter();
        mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
        mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
        mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
        mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
    }

    WifiP2pManager.PeerListListener peerListListener = new WifiP2pManager.PeerListListener() {
        @Override
        public void onPeersAvailable(WifiP2pDeviceList peerList) {
            if (!peerList.getDeviceList().equals(peers)) {
                peers.clear();
                peers.addAll(peerList.getDeviceList());

                deviceNameArray = new String[peerList.getDeviceList().size()];
                deviceArray = new WifiP2pDevice[peerList.getDeviceList().size()];
                int index = 0;

                for (WifiP2pDevice device : peerList.getDeviceList()) {
                    deviceNameArray[index] = device.deviceName;
                    deviceArray[index] = device;
                    index++;
                }

                ArrayAdapter<String> adapter = new ArrayAdapter<>(getApplicationContext(), android.R.layout.simple_list_item_1, deviceNameArray);
                listView.setAdapter(adapter);
            }

            if (peers.size() == 0) {
                Toast.makeText(getApplicationContext(), "No devices found", Toast.LENGTH_SHORT).show();
            }
        }
    };

    WifiP2pManager.ConnectionInfoListener connectionInfoListener = new WifiP2pManager.ConnectionInfoListener() {
        @Override
        public void onConnectionInfoAvailable(WifiP2pInfo wifiP2pInfo) {
            final InetAddress groupOwnerAddress = wifiP2pInfo.groupOwnerAddress;

            if (wifiP2pInfo.groupFormed && wifiP2pInfo.isGroupOwner) {
                connectionStatus.setText("Host");
                serverClass = new ServerClass();
                serverClass.start();
            } else if (wifiP2pInfo.groupFormed) {
                connectionStatus.setText("Client");
                ClientClass client = new ClientClass(groupOwnerAddress);
                clientClass.add(client);
                client.start();
            }
        }
    };

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(mReceiver, mIntentFilter);
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mReceiver);
    }

    private class SendReceive extends Thread {
        private Socket socket;
        private InputStream inputStream;
        private OutputStream outputStream;

        public SendReceive(Socket skt) {
            socket = skt;
            try {
                inputStream = socket.getInputStream();
                outputStream = socket.getOutputStream();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void run() {
            byte[] buffer = new byte[1024];
            int bytes;

            while (socket != null) {
                try {
                    bytes = inputStream.read(buffer);
                    if (bytes > 0) {
                        handler.obtainMessage(MESSAGE_READ, bytes, -1, buffer).sendToTarget();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        public void write(byte[] bytes) {
            try {
                outputStream.write(bytes);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public class ServerClass extends Thread {
        Socket socket;
        ServerSocket serverSocket;

        @Override
        public void run() {
            try {
                serverSocket = new ServerSocket(8888);
                socket = serverSocket.accept();
                sendReceive = new SendReceive(socket);
                sendReceive.start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public class ClientClass extends Thread {
        Socket socket;
        String hostAdd;

        public ClientClass (InetAddress hostAddress) {
            hostAdd = hostAddress.getHostAddress();
            socket = new Socket();
        }

        @Override
        public void run() {
            try {
                socket.connect(new InetSocketAddress(hostAdd, 8888), 500);
                sendReceive = new SendReceive(socket);
                sendReceive.start();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

And this is my WiFiDirectBroadcastReceiver class:

package com.shuzo.musicshare;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.NetworkInfo;
import android.net.wifi.p2p.WifiP2pManager;
import android.widget.Toast;

public class WiFiDirectBroadcastReceiver extends BroadcastReceiver {
    private WifiP2pManager mManager;
    private WifiP2pManager.Channel mChannel;
    private MainActivity mActivity;

    public WiFiDirectBroadcastReceiver(WifiP2pManager manager, WifiP2pManager.Channel channel,
                                       MainActivity activity) {
        super();
        this.mManager = manager;
        this.mChannel = channel;
        this.mActivity = activity;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();

        if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
            int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);

            if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
                Toast.makeText(context, "WiFi is enabled", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(context, "WiFi is disabled", Toast.LENGTH_SHORT).show();
            }
        } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {

            if (mManager != null) {
                mManager.requestPeers(mChannel, mActivity.peerListListener);
            }
        } else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
            if (mManager == null) {
                return;
            }

            NetworkInfo networkInfo = intent.getParcelableExtra(WifiP2pManager.EXTRA_NETWORK_INFO);

            if (networkInfo.isConnected()) {
                mManager.requestConnectionInfo(mChannel, mActivity.connectionInfoListener);
            } else {
                mActivity.connectionStatus.setText("Device disconnected");
            }
        } else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
            // Respond to this device's wifi state changing
        }

    }
}

I'm also requesting all permission needed in my manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.shuzo.musicshare">

    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

My activity_main.xml looks like this:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/ConstraintLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/discover"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@id/connectionStatus"
        android:layout_alignBottom="@id/connectionStatus"
        android:layout_centerHorizontal="true"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="discover"
        app:layout_constraintStart_toEndOf="@+id/switchOnOff"
        app:layout_constraintTop_toBottomOf="@+id/connectionStatus" />

    <ListView
        android:id="@+id/peerListView"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_alignParentStart="true"
        android:layout_marginTop="16dp"
        android:background="@android:color/holo_orange_light"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/discover" />

    <TextView
        android:id="@+id/readMsg"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/peerListView"
        android:layout_alignParentStart="true"
        android:layout_alignParentEnd="true"
        android:layout_marginTop="16dp"
        android:text="Message"
        android:textAlignment="center"
        android:textSize="20sp"
        android:textStyle="italic"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/peerListView" />

    <EditText
        android:id="@+id/writeMsg"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentBottom="true"
        android:layout_toStartOf="@+id/sendButton"
        android:ems="10"
        android:inputType="textPersonName"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/sendButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentBottom="true"
        android:text="Send"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@+id/writeMsg" />

    <TextView
        android:id="@+id/connectionStatus"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="16dp"
        android:text="Connection Status"
        android:textAlignment="center"
        android:textColor="@android:color/holo_blue_dark"
        android:textSize="18sp"
        android:textStyle="italic"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Switch
        android:id="@+id/switchOnOff"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="24dp"
        android:text="WiFi"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/connectionStatus" />
</androidx.constraintlayout.widget.ConstraintLayout>

When I press the discover button on Android 9 the TextView on the top of the activity says "Discovery started" and if I perform this action with a second device which is running Android 8 I can connect these two devices via the ListView. If I want to perform this action on the Android 10 device the TextView says "Discovery starting failed". The Activity on the phone looks like this:

Activity on the phone

Does somebody know how to fix this discovery fail on Android 10?

EDIT: Testing device on Android 10 is a Samsung Galaxy A40.

Answer 1

根据文档，您需要权限android.permission.ACCESS_FINE_LOCATION而不是android.permission.ACCESS_COARSE_LOCATION 。

Answer 2

LocationManager manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        Toast.makeText(this, "please enable location services", Toast.LENGTH_LONG).show();
        startActivity(new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS));
    }

Use this code This will help.I have fixed my issue on android 10 using above code. Keep In mind wifi direct will not work without Gps location.