问Flutter -如何在应用程序处于后台的特定时间执行函数？

EN

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',
   );
 }

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());
}