Start an activity even if we lock the device

Question

I'm developing an alarm aplication, so when the alarm goes on it start an activity with an off button It's very simple, but my question, is there a way to start the activity even if the device is locked???

Answer 1

You need the following permission in AndroidManifest.xml file:

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

Check this link

Answer 2

You need to use the WakeLock and also disable your keyboard for the respective Activity. They can be achieved by help of WindowManager.LayoutParams class.

WakeLock allows your app to wake up the screen i.e. turn the display on while your Activity or your complete app is running in the foreground. To learn more about implementing the WakeLock go through the following link:

http://developer.android.com/training/scheduling/wakelock.html

To disable your keyguard you need to use WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED and/or WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD flags for the respective Activity.

To know more about them, go to the following links:

http://developer.android.com/reference/android/view/WindowManager.LayoutParams.html#FLAG_DISMISS_KEYGUARD

http://developer.android.com/reference/android/view/WindowManager.LayoutParams.html#FLAG_SHOW_WHEN_LOCKED

You will also need to use the following permissions in the Manifest file of your Android Project:

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