1.wifi的五種狀態：
WIFI_STATE_DISABLED WIFI網卡不可用
WIFI_STATE_DISABLING WIFI網卡正在關閉
WIFI_STATE_ENABLED WIFI網卡可用
WIFI_STATE_ENABLING WIFI網卡正在打開
WIFI_STATE_UNKNOWN WIFI網卡狀態不可知
2.要操作WiFi設備，就要使用Context.getSystemService(Context.WIFI_SERVICE)來獲取WifiManager對象，並通過這個對象來管理WiFi設備。
addNetwork(WifiConfiguration config)
添加一個config描述的WIFI網絡，默認情況下，這個WIFI網絡是DISABLE狀態的。 calculateSignalLevel(int rssi , int numLevels)
計算信號的等級 compareSignalLevel(int rssiA, int rssiB)
對比網絡A和網絡B的信號強度 createWifiLock(int lockType, String tag)
創建一個WIFI 鎖，鎖定當前的WIFI連接 disableNetwork(int netId)
讓一個網絡連接失效 disconnect()
斷開當前的WIFI連接 enableNetwork(int netId, Boolean disableOthers)
連接netId所指的WIFI網絡，並是其他的網絡都被禁用 getConfiguredNetworks()
獲取網絡連接的狀態 getConnectionInfo()
獲取當前連接的信息 getDhcpInfo()
獲取DHCP 的信息 getScanResulats()
獲取掃描測試的結果 getWifiState()
獲取當前WIFI設備的狀態 isWifiEnabled()
判斷WIFI設備是否打開 pingSupplicant()
ping操作，和PC的ping操作相同作用 ressociate()
重新連接WIFI網絡，即使該網絡是已經被連接上的 reconnect()
重新連接一個未連接上的WIFI網絡 removeNetwork()
移除某一個網絡 saveConfiguration()
保留一個配置信息 setWifiEnabled()
讓一個連接有效 startScan()
開始掃描 updateNetwork(WifiConfiguration config)
更新一個網絡連接
3.如果要想得到周圍的WIFI熱點列表，可以使用WifiManager.getScanResults()返回一個ScanResult列表，ScanResult對象中，包含了以下幾個屬性：
BSSID 接入點的地址 SSID 網絡的名字，唯一區別WIFI網絡的名字 Capabilities 網絡接入的性能 Frequency 當前WIFI設備附近熱點的頻率(MHz) Level 所發現的WIFI網絡信號強度
4.連接上自定義的WIFI? //根據ID值來自動連接WIFI網絡
//@param index ID值
public void ConnectWifiBySSID(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WifiConfiguration對象來自動連接WIFI網絡
// @param wcg WifiConfiguration對象
public void ConnectWifiByConfig(WifiConfiguration wifiConfiguration) {
int wcgID = mWifiManager.addNetwork(wifiConfiguration);
mWifiManager.enableNetwork(wcgID, true);
}
5.查看已經連接上的WIFI信息，在Android的SDK中為我們提供了一個叫做WifiInfo的對象，這個對象可以通過WifiManager.getConnectionInfo()來獲取。WifiInfo中包含了當前連接中的相關信息。
getBSSID() 獲取BSSID屬性 getDetailedStateOf() 獲取客戶端的連通性 getHiddenSSID() 獲取SSID 是否被隱藏 getIpAddress() 獲取IP 地址 getLinkSpeed() 獲取連接的速度 getMacAddress() 獲取Mac 地址 getRssi() 獲取802.11n 網絡的信號 getSSID() 獲取SSID getSupplicanState() 獲取具體客戶端狀態的信息
wifi管理類
package youcan.text; 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; import android.net.wifi.WifiManager.WifiLock; public class WifiAdmin { // 定義WifiManager對象 private WifiManager mWifiManager; // 定義WifiInfo對象 private WifiInfo mWifiInfo; // 掃描出的網絡連接列表 private List<ScanResult> mWifiList; // 網絡連接列表 private List<WifiConfiguration> mWifiConfiguration; // 定義一個WifiLock WifiLock mWifiLock; // 構造器 public WifiAdmin(Context context) { // 取得WifiManager對象 mWifiManager = (WifiManager) context .getSystemService(Context.WIFI_SERVICE); // 取得WifiInfo對象 mWifiInfo = mWifiManager.getConnectionInfo(); } // 得到WifiManager對象 public WifiManager GetWifiManager() { return mWifiManager; } // 打開WIFI public void OpenWifi() { if (!mWifiManager.isWifiEnabled()) { mWifiManager.setWifiEnabled(true); } } // 關閉WIFI public void CloseWifi() { if (!mWifiManager.isWifiEnabled()) { mWifiManager.setWifiEnabled(false); } } // 鎖定WifiLock public void AcquireWifiLock() { mWifiLock.acquire(); } // 解鎖WifiLock public void ReleaseWifiLock() { // 判斷時候鎖定 if (mWifiLock.isHeld()) { mWifiLock.acquire(); } } // 創建一個WifiLock public void CreatWifiLock() { mWifiLock = mWifiManager.createWifiLock("Test"); } // 得到配置好的網絡 public List<WifiConfiguration> GetConfiguration() { return mWifiConfiguration; } // 指定配置好的網絡進行連接 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); } public void StartScan() { mWifiManager.startScan(); // 得到掃描結果 mWifiList = mWifiManager.getScanResults(); // 得到配置好的網絡連接 mWifiConfiguration = mWifiManager.getConfiguredNetworks(); } // 得到網絡列表 public List<ScanResult> GetWifiList() { return mWifiList; } // 查看掃描結果 public StringBuilder LookUpScan() { StringBuilder stringBuilder = new StringBuilder(); for (int i = 0; i < mWifiList.size(); i++) { stringBuilder .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 stringBuilder.append((mWifiList.get(i)).toString()); stringBuilder.append("\n"); } return stringBuilder; } // 得到MAC地址 public String GetMacAddress() { return (mWifiInfo == null) ? "NULL" : mWifiInfo.getMacAddress(); } // 得到接入點的BSSID public String GetBSSID() { return (mWifiInfo == null) ? "NULL" : mWifiInfo.getBSSID(); } // 得到IP地址 public int GetIPAddress() { return (mWifiInfo == null) ? 0 : mWifiInfo.getIpAddress(); } // 得到連接的ID public int GetNetworkId() { return (mWifiInfo == null) ? 0 : mWifiInfo.getNetworkId(); } // 得到WifiInfo的所有信息包 public String GetWifiInfo() { return (mWifiInfo == null) ? "NULL" : mWifiInfo.toString(); } // 添加一個網絡並連接 public void AddNetwork(WifiConfiguration wcg) { int wcgID = mWifiManager.addNetwork(wcg); mWifiManager.enableNetwork(wcgID, true); } // 斷開指定ID的網絡 public void DisconnectWifi(int netId) { mWifiManager.disableNetwork(netId); mWifiManager.disconnect(); } }
android wifi啟動過程
初始化 在 SystemServer 啟動的時候,會生成一個 ConnectivityService 的實例, try { Log.i(TAG, "Starting Connectivity Service."); ServiceManager.addService(Context.CONNECTIVITY_SERVICE, new ConnectivityService(context)); } catch (Throwable e) { Log.e(TAG, "Failure starting Connectivity Service", e); } ConnectivityService 的構造函數會創建 WifiService, if (DBG) Log.v(TAG, "Starting Wifi Service."); mWifiStateTracker = new WifiStateTracker(context, handler); WifiService wifiService = new WifiService(context, mWifiStateTracker); ServiceManager.addService(Context.WIFI_SERVICE, wifiService); WifiStateTracker 會創建 WifiMonitor 接收來自底層的事件, WifiService 和 WifiMonitor 是整個模塊的核心。 WifiService 負責啟動關閉 wpa_supplicant、啟動關閉 WifiMonitor 監視線程和把命令下發給 wpa_supplicant, 而 WifiMonitor 則負責從 wpa_supplicant 接收事件通知。 連接 AP 1. 使能 WIFI WirelessSettings 在初始化的時候配置了由 WifiEnabler 來處理 Wifi 按鈕, private void initToggles() { mWifiEnabler = new WifiEnabler( this, (WifiManager) getSystemService(WIFI_SERVICE), (CheckBoxPreference) findPreference(KEY_TOGGLE_WIFI) ); } 當用戶按下 Wifi 按鈕后,Android 會調用 WifiEnabler 的 onPreferenceChange, 再由 WifiEnabler調用 WifiManager 的 setWifiEnabled 接口函數, 通過 AIDL,實際調用的是 WifiService 的setWifiEnabled 函數, WifiService 接着向自身發送一條 MESSAGE_ENABLE_WIFI 消息, 在處理該消息的代碼中做真正的使能工作: 首先裝載 WIFI 內核模塊(該模塊的位置硬編碼為"/system/lib/modules/wlan.ko" ), 然 后 啟 動 wpa_supplicant ( 配 置 文 件 硬 編 碼為"/data/misc/wifi/wpa_supplicant.conf") 再通過 WifiStateTracker 來啟動 WifiMonitor 中的監視線程。 private boolean setWifiEnabledBlocking(boolean enable) { final int eventualWifiState = enable ? WIFI_STATE_ENABLED : WIFI_STATE_DISABLED; updateWifiState(enable ? WIFI_STATE_ENABLING : WIFI_STATE_DISABLING); if (enable) { if (!WifiNative.loadDriver()) { Log.e(TAG, "Failed to load Wi-Fi driver."); updateWifiState(WIFI_STATE_UNKNOWN); return false; } if (!WifiNative.startSupplicant()) { WifiNative.unloadDriver(); Log.e(TAG, "Failed to start supplicant daemon."); updateWifiState(WIFI_STATE_UNKNOWN); return false; } mWifiStateTracker.startEventLoop(); } // Success! persistWifiEnabled(enable); updateWifiState(eventualWifiState); return true; } 當使能成功后,會廣播發送 WIFI_STATE_CHANGED_ACTION 這個 Intent 通知外界 WIFI 已經成功使能了。 WifiEnabler 創建的時候就會向 Android 注冊接收WIFI_STATE_CHANGED_ACTION, 因此它會收到該 Intent,從而開始掃描。 private void handleWifiStateChanged(int wifiState) { if (wifiState == WIFI_STATE_ENABLED) { loadConfiguredAccessPoints(); attemptScan(); } 2. 查找 AP 掃描的入口函數是 WifiService 的 startScan,它其實也就是往 wpa_supplicant 發送 SCAN 命令。 static jboolean android_net_wifi_scanCommand(JNIEnv* env, jobject clazz) { jboolean result; // Ignore any error from setting the scan mode. // The scan will still work. (void)doBooleanCommand("DRIVER SCAN-ACTIVE", "OK"); result = doBooleanCommand("SCAN", "OK"); (void)doBooleanCommand("DRIVER SCAN-PASSIVE", "OK"); return result; } 當 wpa_supplicant 處理完 SCAN 命令后,它會向控制通道發送事件通知掃描完成, 從而wifi_wait_for_event 函數會接收到該事件, 由此 WifiMonitor 中的 MonitorThread 會被執行來出來這個事件, void handleEvent(int event, String remainder) { case SCAN_RESULTS: mWifiStateTracker.notifyScanResultsAvailable(); break; WifiStateTracker 則接着廣播發送 SCAN_RESULTS_AVAILABLE_ACTION 這個 Intent case EVENT_SCAN_RESULTS_AVAILABLE: mContext.sendBroadcast(new Intent(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)); WifiLayer 注冊了接收 SCAN_RESULTS_AVAILABLE_ACTION 這個 Intent,所以它的相關 處理函數 handleScanResultsAvailable 會被調用,在該函數中,先會去拿到 SCAN 的結果(最 終是往 wpa_supplicant 發送 SCAN_RESULT 命令並讀取返回值來實現的) , List<ScanResult> list = mWifiManager.getScanResults(); 對每一個掃描返回的 AP,WifiLayer 會調用 WifiSettings 的 onAccessPointSetChanged 函數, 從而最終把該 AP 加到 GUI 顯示列表中。 public void onAccessPointSetChanged(AccessPointState ap, boolean added) { AccessPointPreference pref = mAps.get(ap); if (added) { if (pref == null) { pref = new AccessPointPreference(this, ap); mAps.put(ap, pref); } else { pref.setEnabled(true); } mApCategory.addPreference(pref); } } 3. 配置 AP 參數 當用戶在 WifiSettings 界面上選擇了一個 AP 后,會顯示配置 AP 參數的一個對話框, public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) { if (preference instanceof AccessPointPreference) { AccessPointState state = ((AccessPointPreference) preference).getAccessPointState(); showAccessPointDialog(state, AccessPointDialog.MODE_INFO); } } 4. 連接 當用戶在 AcessPointDialog 中選擇好加密方式和輸入密鑰之后,再點擊連接按鈕,Android 就會去連接這個 AP。 private void handleConnect() { String password = getEnteredPassword(); if (!TextUtils.isEmpty(password)) { mState.setPassword(password); } mWifiLayer.connectToNetwork(mState); } WifiLayer 會先檢測這個 AP 是不是之前被配置過,這個是通過向 wpa_supplicant 發送 LIST_NETWORK 命令並且比較返回值來實現的, // Need WifiConfiguration for the AP WifiConfiguration config = findConfiguredNetwork(state); 如果 wpa_supplicant 沒有這個 AP 的配置信息,則會向 wpa_supplicant 發送 ADD_NETWORK 命令來添加該 AP, if (config == null) { // Connecting for the first time, need to create it config = addConfiguration(state, ADD_CONFIGURATION_ENABLE|ADD_CONFIGURATION_SAVE); } ADD_NETWORK 命 令 會 返 回 一 個 ID , WifiLayer 再用這個返回的ID作為參數向 wpa_supplicant 發送 ENABLE_NETWORK 命令,從而讓 wpa_supplicant 去連接該 AP。 // Make sure that network is enabled, and disable others mReenableApsOnNetworkStateChange = true; if (!mWifiManager.enableNetwork(state.networkId, true)) { Log.e(TAG, "Could not enable network ID " + state.networkId); error(R.string.error_connecting); return false; } 5. 配置 IP 地址 當 wpa_supplicant 成功連接上 AP 之后,它會向控制通道發送事件通知連接上 AP 了,從而 wifi_wait_for_event 函數會接收到該事件,由此 WifiMonitor 中的 MonitorThread 會被執行來 出來這個事件, void handleEvent(int event, String remainder) { case CONNECTED: handleNetworkStateChange(NetworkInfo.DetailedState.CONNECTED,remainder); break; WifiMonitor 再調用 WifiStateTracker 的 notifyStateChange,WifiStateTracker 則接着會往自身 發送 EVENT_DHCP_START 消息來啟動 DHCP 去獲取 IP 地址, private void handleConnectedState() { setPollTimer(); mLastSignalLevel = -1; if (!mHaveIPAddress && !mObtainingIPAddress) { mObtainingIPAddress = true; mDhcpTarget.obtainMessage(EVENT_DHCP_START).sendToTarget(); } } 然后再廣播發送 NETWORK_STATE_CHANGED_ACTION 這個 Intent case EVENT_NETWORK_STATE_CHANGED: if (result.state != DetailedState.DISCONNECTED || !mDisconnectPending) { intent = new Intent(WifiManager.NETWORK_STATE_CHANGED_ACTION); intent.putExtra(WifiManager.EXTRA_NETWORK_INFO, mNetworkInfo); if (result.BSSID != null) intent.putExtra(WifiManager.EXTRA_BSSID, result.BSSID); mContext.sendStickyBroadcast(intent); } break; WifiLayer 注冊了接收 NETWORK_STATE_CHANGED_ACTION 這個 Intent,所以它的相關 處理函數 handleNetworkStateChanged 會被調用, 當 DHCP 拿到 IP 地址之后,會再發送 EVENT_DHCP_SUCCEEDED 消息, private class DhcpHandler extends Handler { public void handleMessage(Message msg) { switch (msg.what) { case EVENT_DHCP_START: if (NetworkUtils.runDhcp(mInterfaceName, mDhcpInfo)) { event = EVENT_DHCP_SUCCEEDED; } WifiLayer 處理 EVENT_DHCP_SUCCEEDED 消息 , 會再次廣播發送 NETWORK_STATE_CHANGED_ACTION 這個 Intent,這次帶上完整的 IP 地址信息。 case EVENT_DHCP_SUCCEEDED: mWifiInfo.setIpAddress(mDhcpInfo.ipAddress); setDetailedState(DetailedState.CONNECTED); intent = new Intent(WifiManager.NETWORK_STATE_CHANGED_ACTION); intent.putExtra(WifiManager.EXTRA_NETWORK_INFO, mNetworkInfo); mContext.sendStickyBroadcast(intent); break; 至此為止,整個連接過程完成 WifiManager wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE); WifiConfiguration wc = new WifiConfiguration(); wc.SSID = ""test"";//ssid wc.preSharedKey = ""12345678"";//ssid密碼 wc.hiddenSSID = true; wc.status = WifiConfiguration.Status.ENABLED; wc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP); wc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP); wc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK); wc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP); wc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP); wc.allowedProtocols.set(WifiConfiguration.Protocol.RSN); int res = wifi.addNetwork(wc); Log.e("WifiPreference", "add Network returned " + res ); boolean b = wifi.enableNetwork(res, true); Log.e("WifiPreference", "enableNetwork returned " + b ); ===================================================================== package src.hero.com; import java.util.ArrayList; import java.util.List; import android.app.ListActivity; import android.net.wifi.ScanResult; import android.net.wifi.WifiConfiguration; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.AdapterView.OnItemClickListener; public class ListOk extends ListActivity implements OnItemClickListener { private ListView lv; private WifiTester wifiTester; // -----------------------連接WIFI private ScanResult scanRet; private WifiConfiguration wc; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.setTitle("當前可用的WIFI列表"); WifiTesterApp _TestActivityApp = (WifiTesterApp) this.getApplication(); wifiTester = (_TestActivityApp).getWifiTester(); wc = new WifiConfiguration(); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, getString(wifiTester.getWifiList())); setListAdapter(adapter); lv = getListView(); lv.setAdapter(adapter); lv.setOnItemClickListener(this); } public String[] getString(List<ScanResult> wifiList) { ArrayList<String> listStr = new ArrayList<String>(); for (int i = 0; i < wifiList.size(); i++) { listStr.add(wifiList.get(i).toString()); } return listStr.toArray(new String[0]); } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { scanRet = wifiTester.getWifiList().get(position); wc.SSID = """ + scanRet.SSID + """; // 配置wifi的SSID，即該熱點的名稱，如：TP-link_xxx wc.preSharedKey = ""7675781777""; // 該熱點的密碼 wc.hiddenSSID = true; wc.status = WifiConfiguration.Status.ENABLED; wc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP); wc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP); wc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK); wc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP); wc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP); wc.allowedProtocols.set(WifiConfiguration.Protocol.RSN); // int res = wifiTester.getMainWifi().addNetwork(wc); // Log.d("Wif iPreference", "1111111add Network returned " + res); // boolean b = wifiTester.getMainWifi().enableNetwork(res, true); // Log.d("WifiPreference", "2222222222enableNetwork returned " + b); } } ============================================================ package jmu84xu.all; import java.net.Inet4Address; import java.util.List; import android.app.Activity; import android.content.Context; import android.net.wifi.WifiConfiguration; import android.net.wifi.WifiInfo; import android.net.wifi.WifiManager; import android.os.Bundle; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.TextView; import android.widget.CompoundButton.OnCheckedChangeListener; public class WifiSet extends Activity implements OnCheckedChangeListener { private WifiManager wifiManager; private WifiInfo wifiInfo; private CheckBox chkOpenCloseWifiBox; private List<WifiConfiguration> wifiConfigurations; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);// 獲得WifiManager對象 wifiInfo = wifiManager.getConnectionInfo();// 獲得連接信息對象 chkOpenCloseWifiBox = (CheckBox)findViewById(R.id.chkOpenCloseWifi); TextView tvWifiConfigurations = (TextView) findViewById(R.id.tvWifiConfigurations); TextView tvWifiInfo = (TextView) findViewById(R.id.tvWifiInfo); chkOpenCloseWifiBox.setOnCheckedChangeListener(this); // 根據當前WIFI的狀態（是否被打開）設置復選框的選中狀態 if (wifiManager.isWifiEnabled()) { chkOpenCloseWifiBox.setText("Wifi已開啟"); chkOpenCloseWifiBox.setChecked(true); } else { chkOpenCloseWifiBox.setText("Wifi已關閉"); chkOpenCloseWifiBox.setChecked(false); } // 獲得WIFI信息 StringBuffer sb = new StringBuffer(); sb.append("Wifi信息n"); sb.append("MAC地址：" + wifiInfo.getMacAddress() + "n"); sb.append("接入點的BSSID：" + wifiInfo.getBSSID() + "n"); sb.append("IP地址（int）：" + wifiInfo.getIpAddress() + "n"); sb.append("IP地址（Hex）：" + Integer.toHexString(wifiInfo.getIpAddress()) + "n"); sb.append("IP地址：" + ipIntToString(wifiInfo.getIpAddress()) + "n"); sb.append("網絡ID：" + wifiInfo.getNetworkId() + "n"); tvWifiInfo.setText(sb.toString()); // 得到配置好的網絡 wifiConfigurations = wifiManager.getConfiguredNetworks(); tvWifiConfigurations.setText("已連接的無線網絡n"); for (WifiConfiguration wifiConfiguration : wifiConfigurations) { tvWifiConfigurations.setText(tvWifiConfigurations.getText() + wifiConfiguration.SSID + "n" ); } } // 將int類型的IP轉換成字符串形式的IP private String ipIntToString(int ip) { try { byte[] bytes = new byte[4]; bytes[0] = (byte) (0xff & ip); bytes[1] = (byte) ((0xff00 & ip) >> 8); bytes[2] = (byte) ((0xff0000 & ip)>> 16); bytes[3] = (byte) ((0xff000000 & ip)>> 24); return Inet4Address.getByAddress(bytes).getHostAddress(); } catch (Exception e) { return""; } } @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { // 當選中復選框時打開WIFI if (isChecked) { wifiManager.setWifiEnabled(true); chkOpenCloseWifiBox.setText("Wifi已開啟"); } // 當取消復選框選中狀態時關閉WIFI else { wifiManager.setWifiEnabled(false); chkOpenCloseWifiBox.setText("Wifi已關閉"); } } } 在AndroidManifest.xml文件中要使用如下的代碼打開相應的權限。 Java代碼： XML/HTML代碼 <uses-permissionandroid:name="android.permission.ACCESS_WIFI_STATE"></uses-permission> <uses-permissionandroid:name="android.permission.WAKE_LOCK"></uses-permission> <uses-permissionandroid:name="android.permission.CHANGE_WIFI_STATE"></uses-permission> ================================================================ package com.eoeandroid.demo.testcode; import java.util.List; import android.app.Activity; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.net.wifi.ScanResult; import android.net.wifi.WifiManager; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.widget.TextView; public class WifiTester extends Activity { TextView mainText; WifiManager mainWifi; WifiReceiver receiverWifi; List<ScanResult> wifiList; StringBuilder sb = new StringBuilder(); public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.WifiTester); setTitle("eoe教程: Wifi Test. -by:IceskYsl"); mainText = (TextView) findViewById(R.id.wifi); mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE); receiverWifi = new WifiReceiver(); registerReceiver(receiverWifi, new IntentFilter( WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)); mainWifi.startScan(); mainText.setText("nStarting Scan...n"); } public boolean onCreateOptionsMenu(Menu menu) { menu.add(0, 0, 0, "Refresh"); return super.onCreateOptionsMenu(menu); } public boolean onMenuItemSelected(int featureId, MenuItem item) { mainWifi.startScan(); mainText.setText("Starting Scan"); return super.onMenuItemSelected(featureId, item); } protected void onPause() { unregisterReceiver(receiverWifi); super.onPause(); } protected void onResume() { registerReceiver(receiverWifi, new IntentFilter( WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)); super.onResume(); } class WifiReceiver extends BroadcastReceiver { public void onReceive(Context c, Intent intent) { sb = new StringBuilder(); wifiList = mainWifi.getScanResults(); for (int i = 0; i < wifiList.size(); i++) { sb.append(new Integer(i + 1).toString() + "."); sb.append((wifiList.get(i)).toString()); sb.append("nn"); } mainText.setText(sb); } } }