Question

我正在开发一个基于WiFi Direct for Android的简单应用程序，它必须连接两个设备。为此，我需要调用funciónonPeersAvailable（myPeerListListener），但我不知道如何。

我的应用有两个要素：

1-Main活动：

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类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
        }
    }
}

到目前为止，我的代码应该能够检测运行应用程序的设备周围的对等方，该ID应存储在变量 myPeerListListener 中。所有这些都发生在名为OnReceiv（）的BroadcastReceiver方法的第二个意图中，通过调用：

 manager.requestPeers(channel, myPeerListListener);

现在我想操纵那个列表。因此，根据API信息，它应该调用requestPeers，您可以在此处查看API：

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

*部分发现同行

所以我试过的是在下面打电话给：

manager.onPeersAvailable(myPeerListListener);

但是我收到了这个错误：

对于类型WifiP2pManager

，未定义onPeersAvailable（WifiP2pManager.PeerListListener）方法

有人能告诉我怎样才能正确地将PeerListListener发送到主活动？

非常感谢你的时间

Answer 1

dtheo已回答并指出关于此主题的精彩Android教程。我将对OP的代码进行更改，以显示如何实现所请求的功能。

根据官方Android指南here，应以这种方式使用wifip2p discovery api：

在您的MainActivity类中：

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类中，请执行以下操作：

@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回答了这个问题。

我只想添加一个小旁注：对于Wi-Fi Direct，两个设备需要同时扫描才能发现彼此。扫描超时也意味着一段时间后可能会丢失可发现性。

Answer 3

您应该在PeerListListener中实现onPeersAvailable方法。

有关详细信息，请参阅http://developer.android.com/training/connect-devices-wirelessly/wifi-direct.html。

Android Wi-Fi Direct：onPeersAvailable

3 个答案: