電源鎖的擷取和釋放

要慎用，否則很消耗電源。
官方的例子
PowerManager pm = (PowerManager)getSystemService(Context.POWER_SERVICE);PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag"); wl.acquire();..screen will stay on during this section.. wl.release();




CPU鎖


PARTIAL_WAKE_LOCK
：很霸道，按下電源鍵cpu仍然運行。

PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);PowerManager.WakeLock wl = pm.newWakeLock(                PowerManager.PARTIAL_WAKE_LOCK |                PowerManager.ACQUIRE_CAUSES_WAKEUP |                PowerManager.ON_AFTER_RELEASE, "My Tag"); wl.acquire();..screen will stay on during this section.. wl.release();





螢幕鎖


PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);PowerManager.WakeLock wl = pm.newWakeLock(                PowerManager.FULL_WAKE_LOCK |                PowerManager.ACQUIRE_CAUSES_WAKEUP |                PowerManager.ON_AFTER_RELEASE, "My Tag"); wl.acquire();..screen will stay on during this section.. wl.release();