Question

I use wakelock to keep the display on.
However, when the app is ended, the display also be turned off.
I want to keep it on after the app is ended.

What should I do?

Answer 1

What you want to do is use the .On_AFTER_RELEASE flag see below.

PowerManager pm;
PowerManager.WakeLock wakeLock;



 // Put the next 5 lines in a method that is called when you want to acquire a wakelock //or in the OnREceive() of a broadcast receiver.`

PowerManager pm = (PowerManager)
         context.getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wakeLock = pm.newWakeLock(
        pm.ON_AFTER_RELEASE|pm.SCREEN_DIM_WAKE_LOCK, "My wakelook");
        wakeLock.acquire();
...Do Stuff here


//Override the onDestroy of your activity to release the wakelock when it is destroyed.
@Override
protected void onDestroy() {

    super.onDestroy();
wakelock.release;
}

This will keep the screen lit up as if someone interacted with the device (pushed the power button, touched the screen, etc.) right when you release the wakelock. At that point a normal power down will occur if there is no further interaction with the device (screen goes dim, and then it goes dark).

I

Let me know if that helped.

Thx

******************Added*************

If you want to wake up the phone from after the screen goes dark you can create your wakelock with the following flags. This is good if you have a broadcast receiver and want to turn on the screen when an event happens so the user can immediately see a UI (Notification, Toast, Layout,etc.)

PowerManager.WakeLock wakeLock = pm.newWakeLock(
             pm.ACQUIRE_CAUSES_WAKEUP|pm.ON_AFTER_RELEASE|pm.SCREEN_DIM_WAKE_LOCK, "My wakelook");