When to unregister BroadcastReceiver? In onPause(), onDestroy(), or onStop()?

Question

When should I use unregisterReceiver? In onPause(), onDestroy(), or onStop()?

Note: I need the service to run in the backgroun

Answer 1

It is just as simple as that, if you want to listen for events even when your activity is not visible then call unregister in onStop() (E.g From Activity A you open Activity B but if you want A to still listening for the events).

But when you only want to listen only for events when your activity is visible then in onPause call unregister() (E.g From Activity A you opened Activity B but now you do not want to listen for events in activity A).

Hope this helps your problem.

Answer 2

it depends on where you have register the receiver. The complementary method pairs are

onCreate - onDestroy
onResume - onPause
onStart  - onStop

if you register the receiver in the first one then unregister it in it's ending method.

Answer 3

From the Android documentation:

You should implement onStop() to release activity resources such as a network connection or to unregister broadcast receivers.

Then, I would follow these pairs (using @StinePike's analogy):

onResume - onPause
onStart  - onStop

Because of the Android Lifecycle, and as @w3bshark mentioned:

In post-HoneyComb (3.0+) devices, onStop() is the last guaranteed handler.

Answer 4

An broadcast receiver is an invisible component. All it does it respond to some kind of an change via onReceive() callback.

So it makes sense to activate them , only when your activity is in a state to respond or when it is becoming Enabled /active - which is when onResume() is called.

So it is a better practice to register in onResume() - When activity is visible & Enabled and unregister in onStop() when activity is no longer Active.