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搬-Android - Wi-Fi Tutorial[转]
http://www.tutorialspoint.com/android/android_wi_fi.htm
Android allows applications to access to view the access the state of the wireless connections at very low level. Application can access almost all the information of a wifi connection.
The information that an application can access includes connected network‘s link speed,IP address, negotiation state(协商状态), other networks information. Applications can also scan, add, save, terminate and initiate Wi-Fi connections.
Android provides WifiManager API to manage all aspects(方面) of WIFI connectivity. We can instantiate this class by calling getSystemService method. Its syntax is given below −
WifiManager mainWifiObj;mainWifiObj = (WifiManager) getSystemService(Context.WIFI_SERVICE);
In order to scan a list of wireless networks, you also need to register your BroadcastReceiver. It can be registered using registerReceiver method with argument of your receiver class object. Its syntax is given below −
lass WifiScanReceiver extends BroadcastReceiver { public void onReceive(Context c, Intent intent) { }}WifiScanReceiver wifiReciever = new WifiScanReceiver();registerReceiver(wifiReciever, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
The wifi scan can be start by calling the startScan method of the WifiManager class. This method returns a list of ScanResult objects. You can access any object by calling the get method of list. Its syntax is given below −
List<ScanResult> wifiScanList = mainWifiObj.getScanResults();String data = wifiScanList.get(0).toString();一般情况下网路环境不怎么变,尽量减少wifi扫描的次数，我自己写程序的时候发现每次扫描的时候要10秒左右才能完成。。。
另外，有的手机 WIFI断开的时候会触发WIFI scan。
下面是一个修改过的WIFI riceiver，利用handler传播消息
package com.example.longer3d.wifi;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.net.NetworkInfo;import android.net.wifi.SupplicantState;import android.net.wifi.WifiInfo;import android.net.wifi.WifiManager;import android.os.Handler;import android.util.Log;public class WifiStatusReceiver extends BroadcastReceiver { /** * wifi连接成功 */ public static final int WIFI_HANDLER_CONNECT_SUCCESS = 0x101; /** * wifi连接失败 */ public static final int WIFI_HANDLER_CONNECT_FAILD = 0x102; /** * wifi连接失败，密码错误,但是只是偶尔会捕抓到=_=.. */ public static final int WIFI_HANDLER_CONNECT_FAILD_AUTH = 0x103; private Handler handler; public WifiStatusReceiver(Handler handler) { this.handler = handler; } @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); switch (action) { case WifiManager.SUPPLICANT_STATE_CHANGED_ACTION: // // 查看源码SupplicantStateTracker.java // SupplicantState supl_state = ((SupplicantState) intent.getParcelableExtra(WifiManager.EXTRA_NEW_STATE)); if (supl_state == SupplicantState.COMPLETED) { // 添加回调 handler.sendEmptyMessage(WIFI_HANDLER_CONNECT_SUCCESS); Log.e("SupplicantState", "wifi COMPLETED"); } else if (supl_state == SupplicantState.DISCONNECTED) { handler.sendEmptyMessage(WIFI_HANDLER_CONNECT_FAILD); Log.e("SupplicantState", "wifi DISCONNECTED"); } else { Log.e("SupplicantState", String.valueOf(supl_state)); Log.e("SupplicantState", "wifi Unknown"); } if (intent.hasExtra(WifiManager.EXTRA_SUPPLICANT_ERROR)) { handler.sendEmptyMessage(WIFI_HANDLER_CONNECT_FAILD_AUTH); Log.e("SupplicantState", "WIFI验证失败！"); } break; // wifi连接上与否 // 会调用的比较快,和多次,不知道为什么,先不使用 case WifiManager.NETWORK_STATE_CHANGED_ACTION: // Log.e("receiver", "网络状态改变"); NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO); if (info.getState().equals(NetworkInfo.State.DISCONNECTED)) { // handler.sendEmptyMessage(WIFI_HANDLER_CONNECT_FAILD); Log.e("receiver", "wifi网络连接断开"); } else if (info.getState().equals(NetworkInfo.State.CONNECTED)) { // 获取当前wifi名称 WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE); WifiInfo wifiInfo = wifiManager.getConnectionInfo(); Log.e("receiver", "连接到网络 " + wifiInfo.getSSID()); // 添加回调 // handler.sendEmptyMessage(WIFI_HANDLER_CONNECT_SUCCESS); } break; // wifi打开与否 case WifiManager.WIFI_STATE_CHANGED_ACTION: int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_DISABLED); if (wifiState == WifiManager.WIFI_STATE_DISABLED) { Log.e("receiver", "系统关闭wifi"); } else if (wifiState == WifiManager.WIFI_STATE_ENABLED) { Log.e("receiver", "系统开启wifi"); } break; } }}
搬-Android - Wi-Fi Tutorial[转]