java Samsung 10 plus不允许wifi p2p发现

Question

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

该应用程序在我的三星Tab E平板电脑上运行得很好——当该应用程序在平板电脑上运行时，我能够扫描并找到其他设备。但在我的三星Galaxy S10 Plus上运行应用程序时，我甚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^{，否则我的三星s10 Plus甚至不会出现在我的平板电脑的可用同行列表中。此时，我的Tab E平板电脑可以“看到”我的Galaxy S10 Plus，但一旦我退出Galaxy S10 Plus上的设置屏幕，Wi-Fi discovery将关闭，我将无法再将其视为潜在的p2p对等机

是否有一种方法允许在三星s10 Plus上进行对等发现？如果没有它，我无法测试我的应用程序，我宁愿不购买另一个Tab E来测试p2p连接

以下是我的应用程序正在运行的代码，以供参考：

import 安卓x.appcompat.app.AppCompatActivity;

import 安卓.content.BroadcastReceiver;
import 安卓.content.Context;
import 安卓.content.IntentFilter;
import 安卓.net.wifi.WifiManager;
import 安卓.net.wifi.p2p.WifiP2pDevice;
import 安卓.net.wifi.p2p.WifiP2pDeviceList;
import 安卓.net.wifi.p2p.WifiP2pManager;
import 安卓.os.Bundle;
import 安卓.view.View;
import 安卓.widget.ArrayAdapter;
import 安卓.widget.Button;
import 安卓.widget.EditText;
import 安卓.widget.ListView;
import 安卓.widget.TextView;
import 安卓.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(),
                        安卓.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 安卓.content.BroadcastReceiver;
import 安卓.content.Context;
import 安卓.content.Intent;
import 安卓.net.wifi.p2p.WifiP2pManager;
import 安卓.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

我有时不使用Android编程，但我认为我的经验可能仍然有效，你可以试试

如果我错了，请纠正我，因此，您开发了一个应用程序，允许您的设备相互发现和连接，而无需访问手机的设置。对于您的S10，您已经安装并打开了应用程序，但您无法通过选项卡发现它，除非您在设置中手动打开它

首先，确保你的应用程序在使用应用程序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"/>

为了确保你的应用程序拥有相应的权限，请在下面的代码中添加相应权限：

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

其次，看看代码库版本。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经过时，并且一些API可能已被弃用