Flutter - How to execute a function at a specific time when the app is in background?

Question

I want to execute a function at a specific time but when the app is closed. The function will display a notification.

This is the function which I want to execute:

Future<void> dailyNotification() async {
DateTime now= DateTime.now();
Time reviewTime = Time(13, 02, 20 );
DateTime notTime = DateTime(now.year, now.month, now.day, reviewTime.hour, reviewTime.minute, reviewTime.second);
var androidChannelSpecifics = AndroidNotificationDetails(
  'CHANNEL_ID 2',
  'CHANNEL_NAME 2',
  "CHANNEL_DESCRIPTION 2",
  importance: Importance.max,
  priority: Priority.high,
 );
 var iosChannelSpecifics = IOSNotificationDetails();
 var platformChannelSpecifics =
 NotificationDetails(android: androidChannelSpecifics, iOS: iosChannelSpecifics);
 await flutterLocalNotificationsPlugin.zonedSchedule(
   2,
   'Test Title at ${reviewTime.hour}:${reviewTime.minute}.${reviewTime.second}',
   'Test Body', //null
    notTime,
    platformChannelSpecifics,
    payload: 'Test Payload',
   );
 }

Edit:

As per the suggestion of Tirth Patel in the post I have implemented it like this:

void callbackDispatcher() {
 Workmanager().executeTask((taskName, inputData) async {
notificationPlugin.showDailyAtTime();
return Future.value(true);
 });
}

void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Workmanager().initialize(callbackDispatcher);
Workmanager().registerPeriodicTask(
  "1",
  "simplePeriodicTask",
  frequency: Duration(minutes: 15),
);
runApp(MyApp());
}

But still, it doesn't work. I am using the flutter local notification package.

I couldn't solve this problem yet.

Please help me with this.

Thanks for your replies.

Does this answer your question? [How to schedule background tasks in Flutter?](https://stackoverflow.com/questions/51706265/how-to-schedule-background-tasks-in-flutter) — Tirth Patel, May 13 '21 at 14:30
Thanks for your reply @TirthPatel I have implemented the code as the first solution in the question you shared, using workmanager. It's not working. Please help. — Sanchay Kasturey, May 13 '21 at 17:51
You didn't call registerPeriodicTask or registerOneOffTask. Check this: https://github.com/fluttercommunity/flutter_workmanager#how-to-use-the-package — Tirth Patel, May 13 '21 at 19:48
I didn't read showDailyAtTime (this function is deprecated) in your code (I assume it is part of the notification plugin), you might not need workmanager. Check this: https://pub.dev/documentation/flutter_local_notifications/latest/flutter_local_notifications/AndroidFlutterLocalNotificationsPlugin/showDailyAtTime.html — Tirth Patel, May 14 '21 at 12:18
Yes @Jitesh Mohite, the notification works i call it using an elevated button and it works. — Sanchay Kasturey, May 16 '21 at 04:32
@SanchayKasturey on which phone/emulator you are running this — Jitesh Mohite, May 16 '21 at 04:51

score 0 · Answer 1 · answered May 16 '21 at 05:30

0

Some of the Android device manufacturing company not allowing the android phone to run in the background, I am sure your device might be one of them.

Solution: we need to enable auto-start in settings for an app to keep a service running. (App info -> Auto Start -> Enable)

answered May 16 '21 at 05:30

Jitesh Mohite

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I have tried what you have said but its still doesn't work – Sanchay Kasturey May 16 '21 at 07:49
add print logs and check in android studio logcat, it will appear. I hope you kililed your application and launching it again – Jitesh Mohite May 16 '21 at 11:26

Flutter - How to execute a function at a specific time when the app is in background?

1 Answers1