How to get screen lock/unlock events on the iPhone when app is suspended?

Question

I have a requirement where i need to track the iphone device state like if device is locked or unlocked. I was able to track these events when the app is running in foreground or background. But i also need to track the same when the app is suspended. Something like tracking the user location in background when the app is suspended. But i don't need to track the user location but only the device state.

Please suggest me some steps to solve this issue in objective-c.Thanks in advance.

Answer 1

You can not perform any operations once your app is in suspended state and you can not prevent your app from getting suspended unless you are using one of the background capability mode mentioned in this apple doc

So what you are looking for is not possible if you are not using either of background modes allowed by apple.

EDIT

Even if you go on and enable one of background mode like background audio, your app is likely to be rejected during review process as reviewer will see you do not have a valid reason to use that particular background mode.