The State of Selected value keeps being reverted back to it's original value - flutter

Question

I want the value of selected to be of the changed one, but everytime I navigate to a different page then come back it keeps returning selected = true
. I tried putting the late bool selected; then initializing in the initState() but it still doesn't work.
bool selected = true;
#override
Widget build(BuildContext context) {
var why = DateTime.parse(
"${DateTime.now().toString().substring(0, 10)} ${widget.time}");
return Container(
padding: EdgeInsets.all(10),
height: 100,
decoration: BoxDecoration(
color: Color(0xFFF9F9FB),
borderRadius: BorderRadius.circular(30),
),
child: Row(
children: [
Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
SizedBox(
width: 15,
),
Center(
child: Text(
"${widget.time}",
style: TextStyle(fontWeight: FontWeight.bold),
),
)
],
),
SizedBox(
width: 50,
),
Container(
height: 100,
width: 1,
color: Colors.grey.withOpacity(0.5),
),
SizedBox(
width: 10,
),
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text("${widget.module}"),
Row(
children: [
Icon(
Icons.location_on,
color: Colors.grey,
size: 20,
),
SizedBox(
width: 3,
),
Text(
"${widget.loc}",
style: TextStyle(
color: Colors.grey,
fontSize: 13,
),
),
],
),
Row(
children: [
Icon(
Icons.person,
color: Colors.grey,
),
SizedBox(
width: 1,
),
Text(
"${widget.lecturer}",
style: TextStyle(
color: Colors.grey,
fontSize: 13,
),
),
],
)
],
),
),
IconButton(
icon: Icon(selected
? Icons.notifications_none
: Icons.notifications_active),
onPressed: () async {
// print(why);
print(widget.time);
print(widget.module);
print(widget.id);
setState(() {
selected = !selected;
});
if (selected == false) {
displayNotification("${widget.module}", why, widget.id);
} else if (selected == true) {
localNotification.cancel(widget.id);
}
},
),
],
),
);
}
Future<void> displayNotification(
String lesson, DateTime lessonTime, int id) async {
FlutterLocalNotificationsPlugin().zonedSchedule(
id,
lesson,
"${lesson} ",
tz.TZDateTime.from(lessonTime, tz.local),
NotificationDetails(
android: AndroidNotificationDetails(
"channel id", "channel name", "channel Description"),
),
uiLocalNotificationDateInterpretation:
UILocalNotificationDateInterpretation.absoluteTime,
androidAllowWhileIdle: true);
}
}
void initializeSetting() async {
var initializeAndroid = AndroidInitializationSettings("#mipmap/ic_launcher");
var initializeSetting = InitializationSettings(android: initializeAndroid);
await localNotification.initialize(initializeSetting);
}

Answer 1

A quick fix :-
Just place your selected variable outside any class like this.
import ...//all the import statements
bool selected = true;
//Rest other code