When should I use unregisterReceiver? In onPause(), onDestroy(), or onStop()?
Note: I need the service to run in the background.
Update:
-
I get an exception releasing receivers
null. -
Activity has leaked intent receivers are you missing call to
unregisterReceiver();
Please tell me if there’s something wrong, here’s my code:
private boolean processedObstacleReceiverStarted;
private boolean mainNotificationReceiverStarted;
protected void onResume() {
super.onResume();
try {
registerReceivers();
} catch (Exception e) {
Log.e(MatabbatManager.TAG,
"MAINActivity: could not register receiver for Matanbbat Action "
+ e.getMessage());
}
}
private void registerReceivers() {
if (!mainNotificationReceiverStarted) {
mainNotificationReceiver = new MainNotificationReceiver();
IntentFilter notificationIntent = new IntentFilter();
notificationIntent
.addAction(MatabbatManager.MATABAT_LOCATION_ACTION);
notificationIntent
.addAction(MatabbatManager.MATABAT_New_DATA_RECEIVED);
notificationIntent
.addAction(MatabbatManager.STATUS_NOTIFCATION_ACTION);
registerReceiver(mainNotificationReceiver, notificationIntent);
mainNotificationReceiverStarted = true;
}
if (!processedObstacleReceiverStarted) {
processedObstacleReceiver = new ProcessedObstacleReceiver();
registerReceiver(processedObstacleReceiver, new IntentFilter(
MatabbatManager.MATABAT_ALARM_LOCATION_ACTION));
processedObstacleReceiverStarted = true;
}
}
private void unRegisterReceivers() {
if (mainNotificationReceiverStarted) {
unregisterReceiver(mainNotificationReceiver);
mainNotificationReceiverStarted = false;
}
if (processedObstacleReceiverStarted) {
unregisterReceiver(processedObstacleReceiver);
processedObstacleReceiverStarted = false;
}
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
try {
unRegisterReceivers();
mWakeLock.release();//keep screen on
} catch (Exception e) {
Log.e(MatabbatManager.TAG, getClass() + " Releasing receivers-" + e.getMessage());
}
}
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：
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：
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：
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.
Tags: androidandroid
