WIFI就是一種無線聯網技術，常見的是使用無線路由器。那麼在這個無線路由器的信號覆蓋的範圍內都可以採用WIFI連接的方式進行聯網。如果無線路由器連接了一個ADSL線路或其他的聯網線路，則又被稱爲“熱點”。
在Android中對Wifi操作，android本身提供了一些有用的包，在android.net.wifi包下面,主要包括以下幾個類和接口：
1.ScanResult
主要用來描述已經檢測出的接入點，包括接入點的地址，接入點的名稱，身份認證，頻率，信號強度等信息。其實就是通過wifi 硬件的掃描來獲取一些周邊的wifi 熱點的信息。
2.WifiConfiguration
Wifi網絡的配置，包括安全設置等，在我們連通一個wifi 接入點的時候，需要獲取到的一些信息。主要包含四個屬性：
BSSID：
BSS是一種特殊的Ad-hoc LAN(一種支持點對點訪問的無線網絡應用模式)的應用，一個無線網絡至少由一個連接到有線網絡的AP和若干無線工作站組成，這種配置稱爲一個基本服務裝置。一羣計算機設定相同的 BSS名稱，即可自成一個group，而此BSS名稱，即所謂BSSID。通常，手機WLAN中，bssid其實就是無線路由的MAC地址。
networkid：網絡ID。
PreSharedKey：無線網絡的安全認證模式。
SSID：SSID(Service Set Identif)用於標識無線局域網，SSID不同的無線網絡是無法進行互訪的。
3.WifiInfo
wifi無線連接的描述，包括（接入點，網絡連接狀態，隱藏的接入點，IP地址，連接速度，MAC地址，網絡ID，信號強度等信息）。這裏簡單介紹一下WifiManager中常用的方法:
| getSSID() | 獲得SSID（熱點名稱） |
getBSSID() | 獲取BSSID |
| getDetailedStateOf() | 獲取客戶端的連通性 |
| getHiddenSSID() | 獲得SSID 是否被隱藏 |
| getIpAddress() | 獲取IP 地址 |
| getLinkSpeed() | 獲得連接的速度 |
| getMacAddress() | 獲得Mac 地址 |
| getRssi() | 獲得802.11n 網絡的信號 |
4.WifiManager
wifi連接統一管理類，獲取WIFI網卡的狀態(WIFI網卡的狀態是由一系列的整形常量來表示的)
| WIFI_STATE_DISABLING = 0 | WIFI網卡正在關閉 |
| WIFI_STATE_DISABLED = 1 | WIFI網卡不可用 |
| WIFI_STATE_ENABLING = 2 | WIFI網正在打開 （WIFI啓動需要一段時間） |
| WIFI_STATE_ENABLED = 3 | WIFI網卡可用 |
| WIFI_STATE_UNKNOWN = 4 | 未知網卡狀態 |
| WIFI_AP_STATE_DISABLING = 10 | WIFI熱點正在關閉 |
| WIFI_AP_STATE_DISABLED = 11 | WIFI熱點不可用 |
| WIFI_AP_STATE_ENABLING = 12 | WIFI熱點正在打開 |
| WIFI_AP_STATE_ENABLED = 13 | WIFI熱點可用 |
5. 在AndroidManifest.xml進行對WIFI操作的權限設置
<!-- 以下是使用wifi訪問網絡所需的權限 --> <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission> <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission> <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>
下面是彙總的一個wifi管理工具類，我完善了一下，並加上了詳細的註解，很實用的！
WifiAdmin類： （wifi管理工具類）
package com.zhf.wifidemo.wifi.utils;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.List;
import android.content.Context;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
/**
* WIFI管理類
* @author ZHF
*
*/
public class WifiAdmin {
private static WifiAdmin wifiAdmin = null;
private List<WifiConfiguration> mWifiConfiguration; //無線網絡配置信息類集合(網絡連接列表)
private List<ScanResult> mWifiList; //檢測到接入點信息類 集合
//描述任何Wifi連接狀態
private WifiInfo mWifiInfo;
WifiManager.WifiLock mWifilock; //能夠阻止wifi進入睡眠狀態，使wifi一直處於活躍狀態
public WifiManager mWifiManager;
/**
* 獲取該類的實例（懶漢）
* @param context
* @return
*/
public static WifiAdmin getInstance(Context context) {
if(wifiAdmin == null) {
wifiAdmin = new WifiAdmin(context);
}
return wifiAdmin;
}
private WifiAdmin(Context context) {
//獲取系統Wifi服務 WIFI_SERVICE
this.mWifiManager = (WifiManager) context.getSystemService("wifi");
//獲取連接信息
this.mWifiInfo = this.mWifiManager.getConnectionInfo();
}
/**
* 是否存在網絡信息
* @param str 熱點名稱
* @return
*/
private WifiConfiguration isExsits(String str) {
Iterator localIterator = this.mWifiManager.getConfiguredNetworks().iterator();
WifiConfiguration localWifiConfiguration;
do {
if(!localIterator.hasNext()) return null;
localWifiConfiguration = (WifiConfiguration) localIterator.next();
}while(!localWifiConfiguration.SSID.equals("\"" + str + "\""));
return localWifiConfiguration;
}
/**鎖定WifiLock，當下載大文件時需要鎖定 **/
public void AcquireWifiLock() {
this.mWifilock.acquire();
}
/**創建一個WifiLock**/
public void CreateWifiLock() {
this.mWifilock = this.mWifiManager.createWifiLock("Test");
}
/**解鎖WifiLock**/
public void ReleaseWifilock() {
if(mWifilock.isHeld()) { //判斷時候鎖定
mWifilock.acquire();
}
}
/**打開Wifi**/
public void OpenWifi() {
if(!this.mWifiManager.isWifiEnabled()){ //當前wifi不可用
this.mWifiManager.setWifiEnabled(true);
}
}
/**關閉Wifi**/
public void closeWifi() {
if(mWifiManager.isWifiEnabled()) {
mWifiManager.setWifiEnabled(false);
}
}
/**端口指定id的wifi**/
public void disconnectWifi(int paramInt) {
this.mWifiManager.disableNetwork(paramInt);
}
/**添加指定網絡**/
public void addNetwork(WifiConfiguration paramWifiConfiguration) {
int i = mWifiManager.addNetwork(paramWifiConfiguration);
mWifiManager.enableNetwork(i, true);
}
/**
* 連接指定配置好的網絡
* @param index 配置好網絡的ID
*/
public void connectConfiguration(int index) {
// 索引大於配置好的網絡索引返回
if (index > mWifiConfiguration.size()) {
return;
}
//連接配置好的指定ID的網絡
mWifiManager.enableNetwork(mWifiConfiguration.get(index).networkId, true);
}
/**
* 根據wifi信息創建或關閉一個熱點
* @param paramWifiConfiguration
* @param paramBoolean 關閉標誌
*/
public void createWifiAP(WifiConfiguration paramWifiConfiguration,boolean paramBoolean) {
try {
Class localClass = this.mWifiManager.getClass();
Class[] arrayOfClass = new Class[2];
arrayOfClass[0] = WifiConfiguration.class;
arrayOfClass[1] = Boolean.TYPE;
Method localMethod = localClass.getMethod("setWifiApEnabled",arrayOfClass);
WifiManager localWifiManager = this.mWifiManager;
Object[] arrayOfObject = new Object[2];
arrayOfObject[0] = paramWifiConfiguration;
arrayOfObject[1] = Boolean.valueOf(paramBoolean);
localMethod.invoke(localWifiManager, arrayOfObject);
return;
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 創建一個wifi信息
* @param ssid 名稱
* @param passawrd 密碼
* @param paramInt 有3個參數，1是無密碼，2是簡單密碼，3是wap加密
* @param type 是"ap"還是"wifi"
* @return
*/
public WifiConfiguration createWifiInfo(String ssid, String passawrd,int paramInt, String type) {
//配置網絡信息類
WifiConfiguration localWifiConfiguration1 = new WifiConfiguration();
//設置配置網絡屬性
localWifiConfiguration1.allowedAuthAlgorithms.clear();
localWifiConfiguration1.allowedGroupCiphers.clear();
localWifiConfiguration1.allowedKeyManagement.clear();
localWifiConfiguration1.allowedPairwiseCiphers.clear();
localWifiConfiguration1.allowedProtocols.clear();
if(type.equals("wt")) { //wifi連接
localWifiConfiguration1.SSID = ("\"" + ssid + "\"");
WifiConfiguration localWifiConfiguration2 = isExsits(ssid);
if(localWifiConfiguration2 != null) {
mWifiManager.removeNetwork(localWifiConfiguration2.networkId); //從列表中刪除指定的網絡配置網絡
}
if(paramInt == 1) { //沒有密碼
localWifiConfiguration1.wepKeys[0] = "";
localWifiConfiguration1.allowedKeyManagement.set(0);
localWifiConfiguration1.wepTxKeyIndex = 0;
} else if(paramInt == 2) { //簡單密碼
localWifiConfiguration1.hiddenSSID = true;
localWifiConfiguration1.wepKeys[0] = ("\"" + passawrd + "\"");
} else { //wap加密
localWifiConfiguration1.preSharedKey = ("\"" + passawrd + "\"");
localWifiConfiguration1.hiddenSSID = true;
localWifiConfiguration1.allowedAuthAlgorithms.set(0);
localWifiConfiguration1.allowedGroupCiphers.set(2);
localWifiConfiguration1.allowedKeyManagement.set(1);
localWifiConfiguration1.allowedPairwiseCiphers.set(1);
localWifiConfiguration1.allowedGroupCiphers.set(3);
localWifiConfiguration1.allowedPairwiseCiphers.set(2);
}
}else {//"ap" wifi熱點
localWifiConfiguration1.SSID = ssid;
localWifiConfiguration1.allowedAuthAlgorithms.set(1);
localWifiConfiguration1.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
localWifiConfiguration1.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
localWifiConfiguration1.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
localWifiConfiguration1.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
localWifiConfiguration1.allowedKeyManagement.set(0);
localWifiConfiguration1.wepTxKeyIndex = 0;
if (paramInt == 1) { //沒有密碼
localWifiConfiguration1.wepKeys[0] = "";
localWifiConfiguration1.allowedKeyManagement.set(0);
localWifiConfiguration1.wepTxKeyIndex = 0;
} else if (paramInt == 2) { //簡單密碼
localWifiConfiguration1.hiddenSSID = true;//網絡上不廣播ssid
localWifiConfiguration1.wepKeys[0] = passawrd;
} else if (paramInt == 3) {//wap加密
localWifiConfiguration1.preSharedKey = passawrd;
localWifiConfiguration1.allowedAuthAlgorithms.set(0);
localWifiConfiguration1.allowedProtocols.set(1);
localWifiConfiguration1.allowedProtocols.set(0);
localWifiConfiguration1.allowedKeyManagement.set(1);
localWifiConfiguration1.allowedPairwiseCiphers.set(2);
localWifiConfiguration1.allowedPairwiseCiphers.set(1);
}
}
return localWifiConfiguration1;
}
/**獲取熱點名**/
public String getApSSID() {
try {
Method localMethod = this.mWifiManager.getClass().getDeclaredMethod("getWifiApConfiguration", new Class[0]);
if (localMethod == null) return null;
Object localObject1 = localMethod.invoke(this.mWifiManager,new Object[0]);
if (localObject1 == null) return null;
WifiConfiguration localWifiConfiguration = (WifiConfiguration) localObject1;
if (localWifiConfiguration.SSID != null) return localWifiConfiguration.SSID;
Field localField1 = WifiConfiguration.class .getDeclaredField("mWifiApProfile");
if (localField1 == null) return null;
localField1.setAccessible(true);
Object localObject2 = localField1.get(localWifiConfiguration);
localField1.setAccessible(false);
if (localObject2 == null) return null;
Field localField2 = localObject2.getClass().getDeclaredField("SSID");
localField2.setAccessible(true);
Object localObject3 = localField2.get(localObject2);
if (localObject3 == null) return null;
localField2.setAccessible(false);
String str = (String) localObject3;
return str;
} catch (Exception localException) {
}
return null;
}
/**獲取wifi名**/
public String getBSSID() {
if (this.mWifiInfo == null)
return "NULL";
return this.mWifiInfo.getBSSID();
}
/**得到配置好的網絡 **/
public List<WifiConfiguration> getConfiguration() {
return this.mWifiConfiguration;
}
/**獲取ip地址**/
public int getIPAddress() {
return (mWifiInfo == null) ? 0 : mWifiInfo.getIpAddress();
}
/**獲取物理地址(Mac)**/
public String getMacAddress() {
return (mWifiInfo == null) ? "NULL" : mWifiInfo.getMacAddress();
}
/**獲取網絡id**/
public int getNetworkId() {
return (mWifiInfo == null) ? 0 : mWifiInfo.getNetworkId();
}
/**獲取熱點創建狀態**/
public int getWifiApState() {
try {
int i = ((Integer) this.mWifiManager.getClass()
.getMethod("getWifiApState", new Class[0])
.invoke(this.mWifiManager, new Object[0])).intValue();
return i;
} catch (Exception localException) {
}
return 4; //未知wifi網卡狀態
}
/**獲取wifi連接信息**/
public WifiInfo getWifiInfo() {
return this.mWifiManager.getConnectionInfo();
}
/** 得到網絡列表**/
public List<ScanResult> getWifiList() {
return this.mWifiList;
}
/**查看掃描結果**/
public StringBuilder lookUpScan() {
StringBuilder localStringBuilder = new StringBuilder();
for (int i = 0; i < mWifiList.size(); i++)
{
localStringBuilder.append("Index_"+new Integer(i + 1).toString() + ":");
//將ScanResult信息轉換成一個字符串包
//其中把包括：BSSID、SSID、capabilities、frequency、level
localStringBuilder.append((mWifiList.get(i)).toString());
localStringBuilder.append("\n");
}
return localStringBuilder;
}
/** 設置wifi搜索結果 **/
public void setWifiList() {
this.mWifiList = this.mWifiManager.getScanResults();
}
/**開始搜索wifi**/
public void startScan() {
this.mWifiManager.startScan();
}
/**得到接入點的BSSID**/
public String GetBSSID() {
return (mWifiInfo == null) ? "NULL" : mWifiInfo.getBSSID();
}
}最後，成功連接到wifi後，通過本機IP地址便可以進行相關網絡開發，在下一篇中我會講解一個WIFI熱點搜索、創建、連接的Demo（http://smallwoniu.blog.51cto.com/3911954/1338618）,希望能幫助到大家！