安卓修改屏幕超时后，系统不进入休眠的方法。

修改系统行为&＃xff0c;让屏幕超时后&＃xff0c;不去休眠。
frameworks\base\services\core\java\com\android\server\power\PowerManagerService&＃xff0c;电源管理类&＃xff0c;屏蔽休眠在此方法中修改。关键函数如下

&＃64;VisibleForTesting
void setWakefulnessLocked(int wakefulness, int reason) {if (mWakefulness !&＃61; wakefulness) {mWakefulness &＃61; wakefulness;mWakefulnessChanging &＃61; true;mDirty |&＃61; DIRTY_WAKEFULNESS;if (mNotifier !&＃61; null) {mNotifier.onWakefulnessChangeStarted(wakefulness, reason);}}
}

重点屏蔽调用这个函数的方法&＃xff0c;即在调用这几个函数的方法开头处&＃xff0c;如果不需要休眠&＃xff0c;则直接返回false。
setWakefulnessLocked(WAKEFULNESS_AWAKE, 0);//这个不用屏蔽
setWakefulnessLocked(WAKEFULNESS_DOZING, reason);
setWakefulnessLocked(WAKEFULNESS_DREAMING, 0);
setWakefulnessLocked(WAKEFULNESS_ASLEEP, PowerManager.GO_TO_SLEEP_REASON_TIMEOUT);

比方说调用setWakefulnessLocked(WAKEFULNESS_ASLEEP, PowerManager.GO_TO_SLEEP_REASON_TIMEOUT);方法的方法是reallyGoToSleepNoUpdateLocked()&＃xff0c;则在方法开头处就根据情况直接返回&＃xff0c;不去执行休眠方法。

// Done dozing, drop everything and go to sleep.private boolean reallyGoToSleepNoUpdateLocked(long eventTime, int uid) {if (DEBUG_SPEW) {Slog.d(TAG, "reallyGoToSleepNoUpdateLocked: eventTime&＃61;" &＃43; eventTime&＃43; ", uid&＃61;" &＃43; uid);}if (eventTime

以上修改完成后&＃xff0c;我们仍然可以知道屏幕什么时候超时&＃xff0c;这样我们可以在超时后做一些自己的逻辑&＃xff0c;比如通知app层&＃xff0c;去做灭屏&＃xff08;只是单纯将屏幕亮度设为0&＃xff09;。屏幕超时后具体执行休眠代码的位置&＃xff1a;