Unable to implement flutter local notifications, please debug code - flutter

Question

I tried the official documentation and also tried following a lot of different guides but somehow i am unable to be able to show a simple local notification on my app. I am confused with completely different lines of code being shown on different guides. My app runs fine without the local notification implementation.
It is a simple app which fetches some data from an API and should display a notification whenever any of the computed data is > 0.
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
FlutterLocalNotificationsPlugin();
Future main() async {
//WidgetsFlutterBinding.ensureInitialized();
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'MyWin App',
theme: ThemeData.dark(
//primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'CoWin paid vaccine availability for 18+'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
void initState() {
super.initState();
const AndroidInitializationSettings initializationSettingsAndroid =
AndroidInitializationSettings('icons8_coronavirus_64.png');
final IOSInitializationSettings initializationSettingsIOS =
IOSInitializationSettings();
final InitializationSettings initializationSettings =
InitializationSettings(
android: initializationSettingsAndroid,
iOS: initializationSettingsIOS,
macOS: null);
flutterLocalNotificationsPlugin.initialize(initializationSettings,
onSelectNotification: selectNotification);
fetchAvailability();
getData();
}
Future selectNotification(String payload) async {
//Handle notification tapped logic here
}
int day = 0;
int sumApolloGariahat = 0;
int sumApolloBypass = 0;
int sumWoodlands = 0;
List<int> availableAtApolloBypass = [];
List<int> availableAtApolloGariahat = [];
List<int> availableAtWoodlands = [];
var url = Uri.parse(
'https://cdn-api.co-vin.in/api/v2/appointment/sessions/public/calendarByDistrict?district_id=725&date=17-05-2021');
Future<http.Response> fetchAvailability() {
return http.get(url);
}
Future getData() async {
var response = await http.get(url);
if (response.statusCode == 200) {
String data = response.body;
Map decodedData = jsonDecode(data);
var apolloGariahatID = decodedData['centers'][11]['center_id'];
var apolloBypassID = decodedData['centers'][16]['center_id'];
var woodlandsID = decodedData['centers'][23]['center_id'];
for (day = 0;
day < decodedData['centers'][12]['sessions'].length;
day++) {
availableAtApolloGariahat.add(decodedData['centers'][12]['sessions']
[day]['available_capacity_dose1']);
}
for (day = 0;
day < decodedData['centers'][16]['sessions'].length;
day++) {
availableAtApolloBypass.add(decodedData['centers'][16]['sessions'][day]
['available_capacity_dose1']);
}
for (day = 0;
day < decodedData['centers'][27]['sessions'].length;
day++) {
availableAtWoodlands.add(decodedData['centers'][27]['sessions'][day]
['available_capacity_dose1']);
}
availableAtApolloGariahat.forEach((e) => sumApolloGariahat += e);
availableAtApolloBypass.forEach((e) => sumApolloBypass += e);
availableAtWoodlands.forEach((e) => sumWoodlands += e);
print('Available at Apollo Gariahat: $sumApolloGariahat');
print('Available at Apollo EM Bypass: $sumApolloBypass');
print('Available at Woodlands: $sumWoodlands');
} else {
print(response.statusCode);
}
}
Future showNotification() async {
const AndroidNotificationDetails androidPlatformChannelSpecifics =
AndroidNotificationDetails(
'your channel id', 'your channel name', 'your channel description',
importance: Importance.max,
priority: Priority.high,
showWhen: false);
const NotificationDetails platformChannelSpecifics =
NotificationDetails(android: androidPlatformChannelSpecifics);
await flutterLocalNotificationsPlugin.show(
0, 'plain title', 'plain body', platformChannelSpecifics,
payload: 'item x');
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'Available at Apollo Gariahat: $sumApolloGariahat',
style: TextStyle(fontSize: 20.0),
),
Text(
'Available at Apollo EM Bypass: $sumApolloBypass',
style: TextStyle(fontSize: 20.0),
),
Text(
'Available at Woodlands: $sumWoodlands',
style: TextStyle(fontSize: 20.0),
),
TextButton(
onPressed: showNotification,
child: Text('Show Notification'),
),
],
),
),
);
}
}

Answer 1

I think there is an issue with the initialisation of your plugin.
You have given your android settings as this.
const AndroidInitializationSettings initializationSettingsAndroid =
AndroidInitializationSettings('icons8_coronavirus_64.png');
You have probably forgot to include this image asset directly in the android/app/src/main/res/drawable folder.
As mentioned in the documentation of flutter_local_notifications, for showing notification on android, all images need to be added into the drawable folder.
I have added my own icon.png into the drawable folder like this,
The, I used it in my initialization, like this
const AndroidInitializationSettings initializationSettingsAndroid =
AndroidInitializationSettings('icon.png');
This fixed the issue for me and I can now see your sample notification.