Android Wi-Fi Direct：onPeers可用

Question

我正在開發一個基於WiFi Direct for Android的簡單應用程序，該應用程序必須連接兩個設備。 為此，我需要調用函數onPeersAvailable（myPeerListListener），但我不知道該怎么做。

我的應用程序具有以下兩個元素：

1-主要活動：

package android.nacho.WifiDirect;



import android.net.wifi.p2p.WifiP2pManager.Channel;

import android.net.wifi.p2p.WifiP2pManager;
import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class WifiDirect extends Activity {


    WifiP2pManager mManager;
    Channel mChannel;
    BroadcastReceiver mReceiver;

    IntentFilter mIntentFilter;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_wifi_direct);


        //To register the BroadastReceiver
        mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
        mChannel =   mManager.initialize(this, getMainLooper(), null); //It was necessary to make a cast (Channel)
        mReceiver = new WiFiBroadcastReceiver(mManager, mChannel, this); //, this);

        //Layout
        final Button btnScan = (Button)findViewById(R.id.btnScan); 
        final TextView TextDebug=(TextView)findViewById(R.id.TextDebug);


        //To define the filter in the BroadcastReceiver
        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);




        final OnClickListener ScanListener=new OnClickListener() //Sacado de TEstPsycologico
        {
            public void onClick(View v){



                TextDebug.setText("Se intentan buscar Peers");

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


                    public void onSuccess() {

                        TextDebug.setText("Ha habido éxito buscando Peers");//DEBUG: Para ver si es posible encontrar Peers

                    }


                    public void onFailure(int reasonCode) {

                        TextDebug.setText("Algo ha salido mal buscando Peers"); //DEBUG: Para ver si pasó algo raro busando Peers
                    }
                });


                onPeersAvailable(myPeerListListener);

            }


        };

        btnScan.setOnClickListener(ScanListener);

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_wifi_direct, menu);
        return true;
    }

    //


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

   // unregister the broadcast receiver
    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(mReceiver);
    }

}

2類BroadcastReceiver：

package android.nacho.WifiDirect;

import android.net.wifi.p2p.WifiP2pManager.Channel;
import android.net.wifi.p2p.WifiP2pManager.PeerListListener;

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



/**
 * A BroadcastReceiver that notifies of important Wi-Fi p2p events.
 */

public class WiFiBroadcastReceiver extends BroadcastReceiver {

    private WifiP2pManager manager;
    private Channel channel;
    private WifiDirect activity;
    private PeerListListener myPeerListListener;

    //For toast, add also context
    //private Context context;

    public WiFiBroadcastReceiver(WifiP2pManager manager, Channel channel, WifiDirect activity){//, Context context) {

        super();
        this.manager = manager;
        this.channel = channel;
        this.activity = activity;
       // this.context= context;
    }

    @Override
    public void onReceive(Context context, Intent intent) {

        String action = intent.getAction();     


        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) {

                //Toast.makeText(context, "Wi-Fi Direct is enable", Toast.LENGTH_LONG).show();

             } else {

                //Toast.makeText(context, "Wi-Fi Direct is not enable", Toast.LENGTH_LONG).show();
             }      

        } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
            // Call WifiP2pManager.requestPeers() to get a list of current peers

             // request available peers from the wifi p2p manager. This is an
            // asynchronous call and the calling activity is notified with a
            // callback on PeerListListener.onPeersAvailable()
            if (manager != null) {
                 manager.requestPeers(channel, myPeerListListener);
                 manager.onPeersAvailable(myPeerListListener);

            }



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

到目前為止，我的代碼應該能夠檢測正在運行該應用程序的設備周圍的對等對象，該ID應該存儲在變量myPeerListListener中 。 所有這些都發生在稱為OnReceiv（）的BroadcastReceiver方法的第二個意圖中，方法是調用：

 manager.requestPeers(channel, myPeerListListener);

現在，我想操作該列表。 因此，按照API信息應該調用requestPeers之后，您可以在此處看到該API：

http://developer.android.com/guide/topics/connectivity/wifip2p.html

*部分發現同行

所以我嘗試的是在下面的調用中寫：

manager.onPeersAvailable(myPeerListListener); 

但是我得到這個錯誤：

對於類型WifiP2pManager，未定義onPeersAvailable（WifiP2pManager.PeerListListener）方法

誰能告訴我如何將PeerListListener正確發送到主活動？

非常感謝您的寶貴時間

Answer 1

dtheo已回答並指向有關此主題的出色的Android教程。 我將對OP的代碼進行更改，以顯示如何實現所需的功能。

根據此處的官方Android指南，應該以這種方式使用wifip2p發現api：

在您的MainActivity類中：

mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
    public void onSuccess() {
        TextDebug.setText("Ha habido éxito buscando Peers");
    }

    public void onFailure(int reasonCode) {
        TextDebug.setText("Algo ha salido mal buscando Peers");
    }
});

// ############# DELETE THE FOLLOWING LINE #############
onPeersAvailable(myPeerListListener); // <<<<<<< DELETE THIS LINE

在您的BroadcastReceiver類中，執行以下操作：

@Override
public void onReceive(Context context, Intent intent) {
    ...    
    if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
        ...
    } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
        if (manager != null) {
            manager.requestPeers(channel, new WifiP2pManager.PeerListListener() {
            @Override
            public void onPeersAvailable(WifiP2pDeviceList peers) {
                Log.d(TAG,String.format("PeerListListener: %d peers available, updating device list", peers.getDeviceList().size()));

                // DO WHATEVER YOU WANT HERE
                // YOU CAN GET ACCESS TO ALL THE DEVICES YOU FOUND FROM peers OBJECT

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

Answer 2

dtheo已經回答了這個問題。

我只想添加一個小注釋：對於Wi-Fi Direct，兩個設備都需要同時掃描才能互相發現。 還有一個掃描超時，這意味着一段時間后可能會丟失可發現性。

Answer 3

您應該在PeerListListener內部實現onPeersAvailable方法。

有關更多信息，請參閱http://developer.android.com/training/connect-devices-wirelessly/wifi-direct.html 。