Flutter Firebase stops listening after push and pop operation - flutter

Question

I'm saving Firebase data in a list using on child Added listener and on child changed listener, it works good, but when i perform push operation and use pop to back to the screen the listeners stops listening.
Is there any solutions to fix this.
I used this code from Stackoverflow : Code

Answer 1

Sorry for this silly post, i'm new to flutter, I fixed this by using Future method in listeners.
#GrahamD you can find my code here.
My code:
var childAddedListener;
var childChangedListener;
#override
void initState(){
FirebaseDatabase database;
database = FirebaseDatabase.instance;
database.setPersistenceEnabled(true);
database.setPersistenceCacheSizeBytes(10000000);
reference = database.reference().child('Sweets');
childAddedListener = reference.onChildAdded.listen(_onEntryAddedShop);
childChangedListener = reference.onChildChanged.listen(_onEntryChangedShop);
super.initState();
}
On Child Added Listener
Future _onEntryAddedShop(Event event) {
setState(() {
itemsShop.add(Sweets.fromSnapshot(event.snapshot));
});
}
On Child Changed Listener
Future _onEntryChangedShop(Event event) {
print('Child Changed');
var old = itemsShop.singleWhere((entry) {
return entry.id == event.snapshot.key;
});
setState(() {
itemsShop[itemsShop.indexOf(old)] = Sweets.fromSnapshot(event.snapshot);
});
getItemIds();
}
Cancel them in dispose
#override
dispose() {
childAddedListener.cancel();
childChangedListener.cancel();
super.dispose();
}