三星 10 plus 不允许 wifi p2p 发现

Question

我编写了一个 Android 应用，允许设备通过 Wi-Fi P2P 发现来发现附近的设备。我正在关注this doc。

该应用程序在我的三星 Tab E 平板电脑上运行良好——当该应用程序在平板电脑上运行时，我能够扫描和查找其他设备。但在我的三星 Galaxy S10 Plus 上运行应用程序时，我什至无法激活对等发现过程。除非我手动进入 Galaxy S10 Plus 的设置并启用Wi-Fi Discovery Mode，否则我的三星 s10 Plus 甚至不会出现在我的平板电脑的可用对等设备列表中。那时，我的 Tab E 平板电脑可以“看到”我的 Galaxy S10 Plus，但是一旦我退出 Galaxy s10 Plus 上的设置屏幕，Wi-Fi 发现就会重新关闭，我无法再看到它潜在的 p2p 对等点。

有没有办法允许在三星 s10 Plus 上进行对等发现？如果没有它，我将无法测试我的应用程序，并且宁愿不必购买另一个 Tab E 来测试 p2p 连接。

以下是我的应用运行的代码供参考：

import androidx.appcompat.app.AppCompatActivity;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.IntentFilter;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pDeviceList;
import android.net.wifi.p2p.WifiP2pManager;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    Button btnOnOff, btnDiscover, btnSend;
    ListView listView;
    TextView read_msg_box, connectionStatus;
    EditText writeMsg;

    //For programmatically turning wifi on and off:
    WifiManager wifiManager;
    WifiP2pManager mManager;
    WifiP2pManager.Channel mChannel;

    BroadcastReceiver mReceiver;
    IntentFilter mIntentFilter = new IntentFilter();

    //For keeping track of available clients to connect to
    List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
    String[] deviceNameArray;
    WifiP2pDevice[] deviceArray;


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

        //initialWork();
        //initializeButtonOnClickListeners();

        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);

        btnDiscover = (Button)findViewById(R.id.discover);
        connectionStatus = (TextView) findViewById(R.id.connectionStatus);

//        btnSend = (Button)findViewById(R.id.sendButton);
        listView = (ListView)findViewById(R.id.peerListView);
//        read_msg_box = (TextView) findViewById(R.id.readMsg);
//        writeMsg = (EditText)findViewById(R.id.writeMsg);

        wifiManager = (WifiManager)getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        initializeOnClickListeners();
    }


    private void initializeOnClickListeners() {

        //Set up functionality for when the discover button is clicked.
        btnDiscover.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "looking for a new peer", Toast.LENGTH_SHORT).show();
                mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
                    @Override
                    public void onSuccess() {
                        connectionStatus.setText("Discovery Started");
                    }

                    @Override
                    public void onFailure(int reason) {
                        connectionStatus.setText("Discovery Failed to start");
                    }
                });
            }
        });
    }

    //Define the logic for when a new peer is discovered
    WifiP2pManager.PeerListListener peerListListener = new WifiP2pManager.PeerListListener() {
        @Override
        public void onPeersAvailable(WifiP2pDeviceList peerList) {
            if(!peerList.getDeviceList().equals(peers)) {
                //clear the peers
                peers.clear();

                //store device list
                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<String>(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();
            }

        }
    };



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

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

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
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;

    WifiP2pManager.PeerListListener myPeerListListener;

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

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        System.out.println("The following action was received: " + action);

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

            //if wifi is enabled
            if(state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
                Toast.makeText(context, "Wifi is ON", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(context, "Wifi is OFF", Toast.LENGTH_LONG).show();
            }
        } else if(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
            Toast.makeText(context, "INSIDE THE P2P_PEERS_CHANGED_ACTION", Toast.LENGTH_LONG).show();
            if(mManager != null) {
                mManager.requestPeers(mChannel, mActivity.peerListListener);
                Toast.makeText(context, "A new peer has been found!!!", Toast.LENGTH_LONG).show();
            }
        } else if(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
            //do something
        } else if(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
            //do something
        }
    }
}

Answer 1

我有时不会在 Android 中编码，但我认为我的经验可能仍然有效，你可以尝试一下。

如果我错了，请纠正我，因此，您开发了一个应用程序，该应用程序允许您的设备发现并相互连接，而无需访问手机的设置。对于您的 S10，您已经安装并打开了该应用，但您无法通过 Tab 找到它，除非您在设置中手动打开它？

首先，确保您的应用在使用应用时添加和请求了所有必需的权限。

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.android.nsdchat"
    ...
    <uses-permission
        android:required="true"
        android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission
        android:required="true"
        android:name="android.permission.ACCESS_WIFI_STATE"/>
    <uses-permission
        android:required="true"
        android:name="android.permission.CHANGE_WIFI_STATE"/>
    <uses-permission
        android:required="true"
        android:name="android.permission.INTERNET"/>

为了确保您的应用具有权限，请将权限添加到下面的代码中以获得相应的权限：

if (ContextCompat.checkSelfPermission(thisActivity, Manifest.permission.CHANGE_WIFI_STATE)
        != PackageManager.PERMISSION_GRANTED) {
    // Permission is not granted
}
...

其次，看代码库版本。由于s10+相当新，Android实际上从Android 8.0开始增强了隐私和安全性。由于库版本的原因，您编写的代码可能已过时，并且某些 API 可能已被弃用。