开启和关闭wifi的代码段

1、需要申请的权限
android.permission.ACCESS_WIFI_STATE 
android.permission.CHANGE_WIFI_STATE 
android.permission.WAKE_LOCK

2、获取WifiManager
wifiManager = (WifiManager) this.getSystemService(Context.WIFI_SERVICE); 

3、开启、关闭wifi
if (wifiManager.isWifiEnabled()) {  
wifiManager.setWifiEnabled(false);  
} else {  
wifiManager.setWifiEnabled(true);  
}