如何解决通过Wi-Fi（android API）发现其他设备？

最近我按照Developer.Android.Com给出的步骤进行操作

但似乎我在那里有一些运气。 我试图发现附近可用的同伴，把他们放入arraylist但似乎没有运气。 我没有得到任何东西。

我的实际2设备实际上是Android 4.1和4.2由于Wifi Direct基于API等级14，这是Android 4.0+所以我认为我的真实设备不是问题。

我使用的概念是使用1个活动和1个BroadCast接收器。

请看看我的代码，我是错误地写了还是忘记了什么？

Chat1Activity.java

package com.example.androtut; import java.util.ArrayList; import others.MyBroadcastReceiver; import android.app.Activity; import android.content.BroadcastReceiver; import android.content.Context; import android.content.IntentFilter; import android.net.wifi.p2p.WifiP2pDeviceList; import android.net.wifi.p2p.WifiP2pManager; import android.net.wifi.p2p.WifiP2pManager.Channel; import android.net.wifi.p2p.WifiP2pManager.PeerListListener; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.Toast; public class Chat1Activity extends Activity { private final IntentFilter mintentFilter = new IntentFilter(); private Channel mChannel; private WifiP2pManager mManager; private BroadcastReceiver mReceiver; private ArrayList peers = new ArrayList(); private PeerListListener myPeerListListener = new PeerListListener() { @Override public void onPeersAvailable(WifiP2pDeviceList peerList) { // Out with the old, in with the new. peers.clear(); peers.addAll(peerList.getDeviceList()); // If an AdapterView is backed by this data, notify it // of the change. For instance, if you have a ListView of available // peers, trigger an update. if (peers.size() == 0) { Toast.makeText(getApplicationContext(),"Nothing found!", Toast.LENGTH_LONG).show(); return; } else { Toast.makeText(getApplicationContext(),"We've found " + peers.size() + " users", Toast.LENGTH_LONG).show(); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_chat1); //Toast.makeText(getApplicationContext(), "Wifi is okay", Toast.LENGTH_LONG).show(); prepareIntentFilter(); Button btn_startchat = (Button) findViewById(R.id.btn_startchat); // Listening to News Feed button click btn_startchat.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { // Launching News Feed Screen detectPeers(); } }); mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE); mChannel = mManager.initialize(this, getMainLooper(), null); } private void detectPeers(){ mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() { @Override public void onSuccess() { // Code for when the discovery initiation is successful goes here. // No services have actually been discovered yet, so this method // can often be left blank. Code for peer discovery goes in the // onReceive method, detailed below. } @Override public void onFailure(int reasonCode) { // Code for when the discovery initiation fails goes here. // Alert the user that something went wrong. } }); } @Override protected void onResume() { super.onResume(); mReceiver = new MyBroadcastReceiver(mManager, mChannel, this, myPeerListListener); registerReceiver(mReceiver, mintentFilter); } /* unregister the broadcast receiver */ @Override protected void onPause() { super.onPause(); unregisterReceiver(mReceiver); } private void prepareIntentFilter() { mintentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION); // Indicates a change in the list of available peers. mintentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION); // Indicates the state of Wi-Fi P2P connectivity has changed. mintentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION); // Indicates this device's details have changed. mintentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION); } } 

和MyBroadcastReceiver.java

 package others; import java.util.ArrayList; import com.example.androtut.Chat1Activity; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.net.wifi.p2p.WifiP2pDevice; import android.net.wifi.p2p.WifiP2pDeviceList; import android.net.wifi.p2p.WifiP2pManager; import android.net.wifi.p2p.WifiP2pManager.Channel; import android.net.wifi.p2p.WifiP2pManager.PeerListListener; import android.widget.Toast; public class MyBroadcastReceiver extends BroadcastReceiver { private WifiP2pManager mManager; private Channel mChannel; private Chat1Activity mActivity; private PeerListListener myPeerListListener; public MyBroadcastReceiver(WifiP2pManager manager, Channel channel, Chat1Activity activity, PeerListListener obPeerList) { super(); this.mManager = manager; this.mChannel = channel; this.mActivity = activity; this.myPeerListListener = obPeerList; } @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 } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) { // Call WifiP2pManager.requestPeers() to get a list of current peers if (mManager != null) { mManager.requestPeers(mChannel, 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 } if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) { int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1); if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) { // Wifi P2P is enabled Toast.makeText(mActivity.getApplicationContext(),"Wifi is okay", Toast.LENGTH_LONG).show(); } else { // Wi-Fi P2P is not enabled Toast.makeText(mActivity.getApplicationContext(), "Wifi is not okay", Toast.LENGTH_LONG).show(); } } } } 

Answer 1

我猜你没有将PeerListListener添加到你的活动中。 所以它不会回复。

您可以尝试在活动中实现PeerListListener

 public class Chat1Activity extends Activity implements WifiP2pManager.PeerListListener 

并覆盖活动中的onPeerAvailable方法

  @Override public void onPeersAvailable(WifiP2pDeviceList peers) { //put your code here } 

并在您的Receiver中更改requestPeers方法

  if (mManager != null) { mManager.requestPeers(mChannel, mActivity); } 

希望这有帮助!!

Answer 2

您是否检查过您的设备是否支持Wifi Direct？ 拥有ROM> 4.0并不意味着它具有wifi直接硬件支持。 尝试使用PackageManager的API检查： http ： //developer.android.com/reference/android/content/pm/PackageManager.html#hasSystemFeature( java.lang.String ）