Android電池電量更新 - BatteryService（轉）

          Log.i(TAG, \\\\\\\"Starting Battery Service.\\\\\\\");
         BatteryService battery = new BatteryService(context);
         ServiceManager.addService(\\\\\\\"battery\\\\\\\", battery);

   gFieldIds.mAcOnline = env->GetFieldID(clazz, \\\\\\\"mAcOnline\\\\\\\", \\\\\\\"Z\\\\\\\"); 
   gFieldIds.mUsbOnline = env->GetFieldID(clazz, \\\\\\\"mUsbOnline\\\\\\\", \\\\\\\"Z\\\\\\\"); 
   gFieldIds.mBatteryStatus = env->GetFieldID(clazz, \\\\\\\"mBatteryStatus\\\\\\\", \\\\\\\"I\\\\\\\"); 
   gFieldIds.mBatteryHealth = env->GetFieldID(clazz, \\\\\\\"mBatteryHealth\\\\\\\", \\\\\\\"I\\\\\\\"); 
   gFieldIds.mBatteryPresent = env->GetFieldID(clazz, \\\\\\\"mBatteryPresent\\\\\\\", \\\\\\\"Z\\\\\\\"); 
   gFieldIds.mBatteryLevel = env->GetFieldID(clazz, \\\\\\\"mBatteryLevel\\\\\\\", \\\\\\\"I\\\\\\\"); 
   gFieldIds.mBatteryTechnology = env->GetFieldID(clazz, \\\\\\\"mBatteryTechnology\\\\\\\", \\\\\\\"Ljava/lang/String;\\\\\\\"); 
   gFieldIds.mBatteryVoltage = env->GetFieldID(clazz, \\\\\\\"mBatteryVoltage\\\\\\\", \\\\\\\"I\\\\\\\"); 
   gFieldIds.mBatteryTemperature = env->GetFieldID(clazz, \\\\\\\"mBatteryTemperature\\\\\\\", \\\\\\\"I\\\\\\\");

#define AC_ONLINE_PATH "/sys/class/power_supply/ac/online"#define USB_ONLINE_PATH "/sys/class/power_supply/usb/online"#define BATTERY_STATUS_PATH "/sys/class/power_supply/battery/status"#define BATTERY_HEALTH_PATH "/sys/class/power_supply/battery/health"#define BATTERY_PRESENT_PATH "/sys/class/power_supply/battery/present"#define BATTERY_CAPACITY_PATH "/sys/class/power_supply/battery/capacity"#define BATTERY_VOLTAGE_PATH "/sys/class/power_supply/battery/batt_vol"#define BATTERY_TEMPERATURE_PATH "/sys/class/power_supply/battery/batt_temp"#define BATTERY_TECHNOLOGY_PATH "/sys/class/power_supply/battery/technology"

<pre class=\"\\"\\\\"kwrd\\\\"\\"\" style=\"\\"\\\\"margin:10px\\"\" intent=\"-----------------------------------------------------------------------------------------------------------------------------------
3. 數據接收
   應用如果想要接收到BatteryService發送出來的電池信息，則需要註冊一個Intent爲Intent.ACTION_BATTERY_CHANGED的BroadcastReceiver。

-----------------------------------------------------------------------------------------------------------------------------------
4. 數據更新
        電池的信息會隨着時間不停變化，自然地，就需要考慮如何實時的更新電池的數據信息。在BatteryService啓動的時候，會同時通過UEventObserver啓動一個onUEvent Thread。

<p style=\"\\"\\\\"margin:10px\\"\">

     在UEvent thread中會不停調用 update()方法，來更新電池的信息數據。

\">