android - 如何在 Android WifiP2pManager onPeersAvailable() 中检索对等列表？

Question

我试图通过 WifiP2pManager 访问 Wifdirect 功能，我试图通过我的 Activity 类中的 onPeersAvailable() 检索对等列表，但无法实现。请建议我如何检索和显示可用的对等点以及在何处编码以进行连接。我的方法如下。

Log.d 没有在这个方法中打印它的值

@Override
    public void onPeersAvailable(WifiP2pDeviceList peerList) {
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
        peers.clear();
        peers.addAll(peerList.getDeviceList());
        Log.e("Peer Size-* * * *", String.valueOf(peers.size())+peerList.toString());

        //((WiFiPeerListAdapter) getListAdapter()).notifyDataSetChanged();
        if (peers.size() == 0) {
            Log.d(MainActivity.TAG, "No devices found");
            Log.e("Peer Size-","No Device Found * * * *");
            return;
        }

    }

主要 Activity

public class MainActivity extends AppCompatActivity implements WifiP2pManager.ChannelListener,WifiP2pManager.PeerListListener {

    WifiP2pManager mManager;
    WifiP2pManager.Channel mChannel;
    BroadcastReceiver mReceiver;
    IntentFilter mIntentFilter;
    public static final String TAG = "MainActivity";

    private List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
    ProgressDialog progressDialog = null;
    View mContentView = null;
    private WifiP2pDevice device;

    private WifiP2pManager manager;
       private boolean isWifiP2pEnabled = false;
       private boolean retryChannel = false;

    private final IntentFilter intentFilter = new IntentFilter();


    TextView value;

/*
    public void setIsWifiP2pEnabled(boolean isWifiP2pEnabled) {
               this.isWifiP2pEnabled = isWifiP2pEnabled;
           }
           */

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        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);


       }


        @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(mReceiver, mIntentFilter);
    }
    /* unregister the broadcast receiver */
    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mReceiver);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();


        manager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {

            @Override
            public void onSuccess() {
                Toast.makeText(MainActivity.this, "Discovery Initiated",
                        Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onFailure(int reasonCode) {
                Toast.makeText(MainActivity.this, "Discovery Failed : " + reasonCode,
                        Toast.LENGTH_SHORT).show();
            }
        });
/*
        Button clk = (Button) findViewById(R.id.showDetails);
        clk.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //Toast.makeText(MainActivity.this, "Button Clicked", Toast.LENGTH_SHORT).show();
                TextView view2 = (TextView) findViewById(R.id.value);
                view2.setText(device.deviceAddress);

            }
        });
*/

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }


        return super.onOptionsItemSelected(item);
    }




    @Override
    public void onPeersAvailable(WifiP2pDeviceList peerList) {
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
        peers.clear();
        peers.addAll(peerList.getDeviceList());
        Log.e("Peer Size-* * * *", String.valueOf(peers.size())+peerList.toString());

        //((WiFiPeerListAdapter) getListAdapter()).notifyDataSetChanged();
        if (peers.size() == 0) {
            Log.d(MainActivity.TAG, "No devices found");
            Log.e("Peer Size-","No Device Found * * * *");
            return;
        }

    }

    @Override
    public void onChannelDisconnected() {

        // we will try once more
        if (manager != null && !retryChannel) {
            Toast.makeText(this, "Channel lost. Trying again", Toast.LENGTH_LONG).show();
           // resetData();
            retryChannel = true;
            manager.initialize(this, getMainLooper(), this);
        } else {
            Toast.makeText(this,
                    "Severe! Channel is probably lost premanently. Try Disable/Re-Enable P2P.",
                    Toast.LENGTH_LONG).show();
        }

    }
}

这是广播接收器

public class WiFiDirectBroadcastReceiver extends BroadcastReceiver  {

    private WifiP2pManager mManager;
    private WifiP2pManager.Channel mChannel;
    private MainActivity mActivity;
    WifiP2pManager.PeerListListener myPeerListListener;

    private List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
    ProgressDialog progressDialog = null;
    View mContentView = null;
    private WifiP2pDevice device;


    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();


        mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
            @Override
            public void onSuccess() {
                Toast.makeText(mActivity, "Channel Received", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onFailure(int reasonCode) {
                Toast.makeText(mActivity, "Channel Not Received", Toast.LENGTH_SHORT).show();
            }
        });

        if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
            // Check to see if Wi-Fi is enabled and notify appropriate activity

            int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
            if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
                // Wifi Direct mode is enabled
                //mActivity.setIsWifiP2pEnabled(true);
                Log.e("WifiDIRECT-","Enabled");
            } else {
                //mActivity.setIsWifiP2pEnabled(false);
                Log.e("WifiDIRECT-","Disabled");
               // mActivity.resetData();

            }
            Log.d(MainActivity.TAG, "P2P state changed - " + state);

        } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {

            if (mManager != null) {
                mManager.requestPeers(mChannel, myPeerListListener );
                Log.e("Peer Changed:", "Detected Peer");
            }

            // Call WifiP2pManager.requestPeers() to get a list of current peers

        } else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
            // Respond to new connection or disconnections
            if (mManager == null) {
                return;
            }
        } else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
            // Respond to this device's wifi state changing
        }

    }



}

Answer 1

为什么在 WifiDirectBroadCastReceiver 的 onReceive 方法中调用 discoverPeers？每次触发 Intent 时都不会继续调用 discoverPeers(您的 BroadcastReceiver 已注册)。

此外，这可能看起来很愚蠢，但是在您尝试查找它们时，您是否有任何其他设备正在运行 discoverPeers。在 android 中，唯一确认您的设备是否启用 Wifi-Direct 的方法是从它调用 discoverPeers(或转到 Settings->Wifi Settings->Wifi Direct->Scan)。

因此，只有当两个设备都调用各自的 discoverPeers 时，才会在 onPeersAvailable 中的彼此的 peerList 中找到它们。