How to get an Android WakeLock to work?

Question

My WakeLock isn't keeping my device awake.

In OnCreate() I've got:

PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); mWakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE, "My Tag"); mWakeLock.acquire(); 

then:

new CountDownTimer(1320000, 200) {      public void onTick(long millisUntilFinished) {         // I update a progress bar here.                                              }      public void onFinish() {         // I finish updating the progress bar.         mWakeLock.release();     } }.start(); 

The screen turns off before the timer finishes, how can I make the screen stay visible?

mWakeLock is a field previously declared like so:

private PowerManager.WakeLock mWakeLock; 

My device uses Android 1.6. I would really appreciate any help to resolve this.

Answer 1

WakeLock doesn't usually cause Reboot problems. There may be some other issues in your coding. WakeLock hogs battery heavily, if not released after usage.

WakeLock is an Inefficient way of keeping the screen on. Instead use the WindowManager to do the magic. The following one line will suffice the WakeLock. The WakeLock Permission is also needed for this to work. Also this code is more efficient than the wakeLock.

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); 

You need not relase the WakeLock Manually. This code will allow the Android System to handle the Lock Automatically. When your application is in the Foreground then WakeLock is held and else android System releases the Lock automatically.

Try this and post your comment...

Answer 2

Do you have the required permission set in your Manifest?

<uses-permission android:name="android.permission.WAKE_LOCK" />