在上一篇文章《Android開發(fā)實踐：WIFI掃描功能的封裝》介紹了如何利用Andriod的API實現(xiàn)WIFI的掃描，本文則重點講述一下如何連接WIFI吧，在此，也給出一個封裝WIFI連接過程的類，提供簡單的接口以供在各個代碼工程中復(fù)用。
與WIFI掃描類似，WIFI的連接同樣是一個耗時的過程，所以需要放到線程中執(zhí)行，通過回調(diào)來通知調(diào)用者連接結(jié)果。該回調(diào)接口的定義如下：
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public interface WifiConnectListener {
public void OnWifiConnectCompleted( boolean isConnected );
}從Android的WIFI Setting可以看出，一般添加一個新的WIFI連接，需要給出三個信息，一個是WIFI的SSID，一個是WIFI的密碼，另一個是WIFI的加密類型，不同的加密方式，連接時程序中的配置是不同的，這里定義一個枚舉，給出四種常見的加密類型：
public enum SecurityMode {
OPEN, WEP, WPA, WPA2
}Android的WIFI連接過程，總體上分為三步，第一步，添加網(wǎng)絡(luò)配置，第二步，根據(jù)網(wǎng)絡(luò)配置連接WIFI，第三步，監(jiān)聽系統(tǒng)的WIFI連接狀態(tài)消息。下面就直接給出示例代碼，關(guān)鍵的地方都在代碼中注釋了。
package com.example.testwifi;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.SupplicantState;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
public class WifiConnector {
private static final int WIFI_CONNECT_TIMEOUT = 20; //連接WIFI的超時時間
private Context mContext;
private WifiManager mWifiManager;
private Lock mLock;
private Condition mCondition;
private WiFiConncetReceiver mWifiConnectReceiver;
private WifiConnectListener mWifiConnectListener;
private boolean mIsConnnected = false;
private int mNetworkID = -1;
//網(wǎng)絡(luò)加密模式
public enum SecurityMode {
OPEN, WEP, WPA, WPA2
}
//通知連接結(jié)果的監(jiān)聽接口
public interface WifiConnectListener {
public void OnWifiConnectCompleted( boolean isConnected );
}
public WifiConnector( Context context , WifiConnectListener listener ) {
mContext = context;
mLock = new ReentrantLock();
mCondition = mLock.newCondition();
mWifiManager=(WifiManager)mContext.getSystemService(Context.WIFI_SERVICE);
mWifiConnectReceiver = new WiFiConncetReceiver();
mWifiConnectListener = listener;
}
public void connect( final String ssid, final String password, final SecurityMode mode ) {
new Thread(new Runnable() {
@Override
public void run() {
//如果WIFI沒有打開，則打開WIFI
if( !mWifiManager.isWifiEnabled() ) {
mWifiManager.setWifiEnabled(true);
}
//注冊連接結(jié)果監(jiān)聽對象
mContext.registerReceiver(mWifiConnectReceiver, new IntentFilter(WifiManager.SUPPLICANT_STATE_CHANGED_ACTION));
//連接指定SSID
if( !onConnect(ssid,password,mode) ) {
mWifiConnectListener.OnWifiConnectCompleted(false);
}
else {
mWifiConnectListener.OnWifiConnectCompleted(true);
}
//刪除注冊的監(jiān)聽類對象
mContext.unregisterReceiver(mWifiConnectReceiver);
}
}).start();
}
protected boolean onConnect( String ssid, String password, SecurityMode mode ) {
//添加新的網(wǎng)絡(luò)配置
WifiConfiguration cfg = new WifiConfiguration();
cfg.SSID = "\"" + ssid + "\"";
if( password !=null && !"".equals(password) ) {
//這里比較關(guān)鍵，如果是WEP加密方式的網(wǎng)絡(luò)，密碼需要放到cfg.wepKeys[0]里面
if( mode == SecurityMode.WEP ) {
cfg.wepKeys[0] = "\"" + password + "\"";
cfg.wepTxKeyIndex = 0;
}
else {
cfg.preSharedKey = "\"" + password + "\"";
}
}
cfg.status = WifiConfiguration.Status.ENABLED;
//添加網(wǎng)絡(luò)配置
mNetworkID = mWifiManager.addNetwork(cfg);
mLock.lock();
mIsConnnected = false;
//連接該網(wǎng)絡(luò)
if( !mWifiManager.enableNetwork(mNetworkID , true) ) {
mLock.unlock();
return false;
}
try {
//等待連接結(jié)果
mCondition.await(WIFI_CONNECT_TIMEOUT, TimeUnit.SECONDS);
}
catch (InterruptedException e) {
e.printStackTrace();
}
mLock.unlock();
return mIsConnnected;
}
//監(jiān)聽系統(tǒng)的WIFI連接消息
protected class WiFiConncetReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if (!WifiManager.SUPPLICANT_STATE_CHANGED_ACTION.equals(intent.getAction())) {
return;
}
mLock.lock();
WifiInfo info = mWifiManager.getConnectionInfo();
if ( info.getNetworkId()==mNetworkID && info.getSupplicantState() == SupplicantState.COMPLETED ) {
mIsConnnected = true;
mCondition.signalAll();
}
mLock.unlock();
}
}
}與WIFI掃描的封裝代碼類似，這里也用到了Lock和Condition，就是為了阻塞地等待WIFI連接的結(jié)果，保證正確的registerReceiver和unregisterReceiver網(wǎng)絡(luò)連接狀態(tài)監(jiān)聽對象，同時，設(shè)置了WIFI連接超時，防止由于WIFI模塊的問題導(dǎo)致界面收不到回調(diào)而長時間“卡死”。
另外，AndroidManifest.xml文件中記得添加權(quán)限支持哦：
