android4.0以后增加了wifidirect直接连接，两台手机可以通过wifidirect直接连接，方便快速传递东西。
其中涉及到了几个常用的类
WifiP2pDevice表示具体的wifi设备
WifiManager用于代开关闭wifi状态的
WifiP2pManager用来控制整个连接过程操作的类
WifiP2pInfo用于获取连接设备信息的类
具体流程：
首先自定义一个广播接收者，，用于监听mWifiP2pManager.initialize(MainActivity.this,getMainLooper(),null);返回的wifidirect状态，包含四个action，WifiDirectBroadReceiver.java
@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubString action = intent.getAction();if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {//P2P功能是否打开int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE,-1);// EXTRA_WIFI_STATE 为发现wifi P2p是否可见的keyif (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {Log.d(TAG, "t"+state);}else{Log.d(TAG, "f"+state);}}if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {// 发现对等p2pif (manager != null) {manager.requestPeers(channel, (PeerListListener)activity);//Log.d(TAG, "WIFI_P2P_PEERS_CHANGED_ACTION请求当前对等信息执行");}}if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {//显示自己p2p信息activity.updateThisDevice((WifiP2pDevice) intent.getParcelableExtra(WifiP2pManager.EXTRA_WIFI_P2P_DEVICE));Log.d(TAG,"显示自己的设备信息");}if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {//连接actionif (null == manager) {return;}NetworkInfo netWorkInfo = intent.getParcelableExtra(WifiP2pManager.EXTRA_NETWORK_INFO);if (netWorkInfo.isConnected()) {manager.requestConnectionInfo(channel,(ConnectionInfoListener)activity);}else {activity.resetData();}}}新建类FindPeers实现PeerListListener接口，当搜索到可用的wifi设备时候，回调onPeersAvailable(WifiP2pDeviceList deviceList)方法
FindPeers.java
public class FindPeers implements PeerListListener {private static final String TAG = "findpeers";private List<WifiP2pDevice>list = new ArrayList<WifiP2pDevice>();private ProgressDialog progressDialog = null;private Context context;private WifiManager manager;private ListView listView;private Handler handler;public FindPeers(Context context,Handler handler) {this.context = context;manager = (WifiManager) context.getSystemService(context.WIFI_SERVICE);this.handler = handler;}/** * 搜索对等的peers 启动WIFI_P2P_STATE_ENABLED action */@Overridepublic void onPeersAvailable(WifiP2pDeviceList deviceList) {list.clear();list.addAll(deviceList.getDeviceList());handler.sendEmptyMessage(1);}public boolean isWifiEnable() {if (manager != null) {return manager.isWifiEnabled();}else{return false;}}public void openWifi() {manager.setWifiEnabled(true);}public List<WifiP2pDevice> getP2pDevice() {return list;}}最后在MainActivity中的oncreate方法中进行IntentFilter必要的初始化，以及在onresume中注册已经写好的广播接受者
MainActivity.java
package com.example.wifidirect;import java.util.ArrayList;import java.util.List;import android.annotation.SuppressLint;import android.app.Activity;import android.app.ProgressDialog;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.net.wifi.WifiManager;import android.net.wifi.WpsInfo;import android.net.wifi.p2p.WifiP2pConfig;import android.net.wifi.p2p.WifiP2pDevice;import android.net.wifi.p2p.WifiP2pDeviceList;import android.net.wifi.p2p.WifiP2pInfo;import android.net.wifi.p2p.WifiP2pManager;import android.net.wifi.p2p.WifiP2pManager.ActionListener;import android.net.wifi.p2p.WifiP2pManager.ChannelListener;import android.net.wifi.p2p.WifiP2pManager.ConnectionInfoListener;import android.net.wifi.p2p.WifiP2pManager.PeerListListener;import android.os.Build;import android.os.Bundle;import android.os.Handler;import android.telephony.TelephonyManager;import android.util.Log;import android.view.KeyEvent;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.ViewGroup;import android.view.Window;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.ArrayAdapter;import android.widget.Button;import android.widget.EditText;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity implements PeerListListener,ConnectionInfoListener,ChannelListener {private static final String TAG = "MainActivity";private final IntentFilter mIntentFilter = new IntentFilter();private WifiP2pManager mWifiP2pManager;//连接设备信息private WifiP2pInfo mInfo;private boolean isP2pEnabled = false;private List<WifiP2pDevice> mpeers =new ArrayList<WifiP2pDevice>();private ProgressDialog mProgressDialog = null;private WifiP2pDevice mWifiP2pDevice;private WifiP2pManager.Channel mChannel;private ListView mListView ;WifiPeerListAdapter adapter;private Button mSearchBtn;private FindPeers findPeers;private boolean retryChanel = false;private WifiDirectBroadReceiver mReceiver;/**自己设备的状态 */private String mStatus = "avaliable";private TextView mRename;private static final int DIALOG_DISCONNECT = 1;private static final int DIALOG_CANCEL_CONNECT = 2;private static final int DIALOG_RENAME = 3;String deviceName = "temp";Handler mHandler = new Handler() {public void handleMessage(android.os.Message msg) {switch (msg.what) {case 1:setAdapter();break;default:break;}};};@SuppressLint("ShowToast")@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_NO_TITLE);setContentView(R.layout.activity_main);init();/**可以探测到有效距离内的对等设备*/mWifiP2pManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {@Overridepublic void onSuccess() {//只会对成功探测到对等设备这一事件做出通知，而并不会提供任何关于已发现的对等设备的具体信息：}@Overridepublic void onFailure(int arg0) {// TODO Auto-generated method stub}});}private void init() {mListView = (ListView) findViewById(R.id.lv);mRename = (TextView) findViewById(R.id.rename);mSearchBtn = (Button) findViewById(R.id.search);findPeers = new FindPeers(MainActivity.this,mHandler);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);mWifiP2pManager = (WifiP2pManager) getSystemService(WIFI_P2P_SERVICE);if (null != mWifiP2pManager) {mChannel = mWifiP2pManager.initialize(MainActivity.this,getMainLooper(),null);if (mChannel == null) {Log.d(TAG,"setup connection fail");mWifiP2pManager = null;}}else{Log.d(TAG, "mWifiP2pManager is null");}mSearchBtn.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubif (!findPeers.isWifiEnable()) {findPeers.openWifi();}mpeers.clear();setAdapter();mWifiP2pManager.discoverPeers(mChannel, new ActionListener() {@Overridepublic void onSuccess() {// TODO Auto-generated method stubToast.makeText(MainActivity.this,"discover success",Toast.LENGTH_SHORT).show();}@Overridepublic void onFailure(int arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this,"discover fail",Toast.LENGTH_SHORT).show();}});}});}/** * 自定义显示adapter * @author user * */private class WifiPeerListAdapter extends ArrayAdapter<WifiP2pDevice> {private List<WifiP2pDevice>items;public WifiPeerListAdapter(Context context,int textViewResourceId, List<WifiP2pDevice> objects) {super(context, textViewResourceId, objects);items = objects;}public List<WifiP2pDevice> getItems() {return items;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View v = convertView;if (null == v) {v = LayoutInflater.from(MainActivity.this).inflate(R.layout.row_devices1,null);}final WifiP2pDevice deviceInfo = items.get(position);if (deviceInfo != null) {TextView deviceName = (TextView) v.findViewById(R.id.device_name);TextView deviceDetail = (TextView) v.findViewById(R.id.device_details);if (null != deviceName) {deviceName.setText(deviceInfo.deviceName);}if (null != deviceDetail) {deviceDetail.setText(getStateStatus(deviceInfo.status));}final Button connect = (Button) v.findViewById(R.id.connect);if ("avaliable".equalsIgnoreCase(getStateStatus(deviceInfo.status))) {connect.setText("链接");}if ("connnected".equalsIgnoreCase(getStateStatus(deviceInfo.status))) {connect.setText("断开");}connect.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubif (connect.getText().equals("链接")) {connect(createP2pConfig(deviceInfo));}if (connect.getText().equals("断开")) {cancleConnect(deviceInfo);}}});}return v;}}/** * 得到链接的状态 * @param deviceStatus * @return */private static String getStateStatus(int deviceStatus) {switch (deviceStatus) {case WifiP2pDevice.AVAILABLE:return "avaliable";case WifiP2pDevice.CONNECTED:return "connnected";case WifiP2pDevice.FAILED:return "failed";case WifiP2pDevice.INVITED:return "invited";case WifiP2pDevice.UNAVAILABLE:return "unavailable";default:return "unknow";}}/** * 连接指定的peer * @param config */public void connect(WifiP2pConfig config) {mWifiP2pManager.connect(mChannel, config, new ActionListener() {@Overridepublic void onSuccess() {// TODO Auto-generated method stub//Log.d(TAG, "链接到设备："+mWifiP2pDevice.deviceName+"ipaddress:"+mWifiP2pDevice.deviceAddress);}@Overridepublic void onFailure(int arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this,"connectfail",Toast.LENGTH_SHORT).show();}});}/** * 根据device的信息，创建配置信息 * @param device * @return */public WifiP2pConfig createP2pConfig(WifiP2pDevice device) {WifiP2pConfig config = new WifiP2pConfig();config.deviceAddress = device.deviceAddress;config.wps.setup = WpsInfo.PBC;return config;}public void cancleConnect(WifiP2pDevice device) {if (null != mWifiP2pManager) {if (device == null || device.status == WifiP2pDevice.CONNECTED) {disConnect();}else if (device.status == WifiP2pDevice.AVAILABLE || device.status == WifiP2pDevice.INVITED) {mWifiP2pManager.cancelConnect(mChannel, new ActionListener() {@Overridepublic void onSuccess() {// TODO Auto-generated method stubToast.makeText(MainActivity.this,"cancleConnect success",Toast.LENGTH_LONG).show();}@Overridepublic void onFailure(int arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this,"cancleconnect fail error"+arg0,Toast.LENGTH_LONG).show();}});}}}/** * 断开连接 */public void disConnect() {mWifiP2pManager.removeGroup(mChannel, new ActionListener() {@Overridepublic void onSuccess() {// TODO Auto-generated method stubmpeers.clear();setAdapter();}@Overridepublic void onFailure(int arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this,"disconnect fail error"+arg0,Toast.LENGTH_LONG).show();}});}public void setAdapter() {if (null == adapter) {adapter = new WifiPeerListAdapter(MainActivity.this,R.layout.row_devices,mpeers);mListView.setAdapter(adapter);}else{for (WifiP2pDevice device: mpeers) {String name = device.deviceName;String sta = getStateStatus(device.status);}((WifiPeerListAdapter)mListView.getAdapter()).notifyDataSetChanged();}}/** * action WIFI_P2P_THIS_DEVICE_CHANGED_ACTION检测自身device 显示自身设备信息 * @param device */public void updateThisDevice(WifiP2pDevice device) {this.mWifiP2pDevice = device;TextView viewOne = (TextView) this.findViewById(R.id.tv);TextView viewTwo = (TextView) this.findViewById(R.id.tv1);String name = device.deviceName;String status = device.status+"";viewOne.setText(device.deviceName);viewTwo.setText(getStateStatus(device.status));mStatus = getStateStatus(device.status);Log.d(TAG, "连接前自己的地址"+device.deviceAddress);}/** * 清空自身信息 */public void resetData() {mWifiP2pDevice = null;mpeers.clear();setAdapter();}@Overrideprotected void onResume() {super.onResume();if (mReceiver == null) {mReceiver = new WifiDirectBroadReceiver(mWifiP2pManager, mChannel, this, findPeers);}registerReceiver(mReceiver, mIntentFilter);}@Overrideprotected void onPause() {// TODO Auto-generated method stubsuper.onPause();if (mWifiP2pManager != null) {mWifiP2pManager.stopPeerDiscovery(mChannel, null);}unregisterReceiver(mReceiver);}@Overridepublic void onPeersAvailable(WifiP2pDeviceList deviceList) {// TODO Auto-generated method stubmpeers.clear();mpeers.addAll(deviceList.getDeviceList());((WifiPeerListAdapter)mListView.getAdapter()).notifyDataSetChanged();if (mpeers.size() == 0) {Log.d(TAG, "no peer found");}mHandler.sendEmptyMessage(1);}@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {// TODO Auto-generated method stubif (keyCode == KeyEvent.KEYCODE_BACK) {if (mStatus.equalsIgnoreCase("Connect")) {disConnect();}}return super.onKeyDown(keyCode, event);}@Overridepublic void onChannelDisconnected() {// TODO Auto-generated method stubif (mWifiP2pManager != null || ! retryChanel) {resetData();retryChanel = true;mWifiP2pManager.initialize(MainActivity.this,getMainLooper(),this);}}@Overridepublic void onConnectionInfoAvailable(WifiP2pInfo arg0) {// TODO Auto-generated method stub}}源码连接：
开始的时侯，我们就知道，总会有终结。
