你可以用这个-

import 'package:flutter/material.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:workmanager/workmanager.dart';

void main() {

// needed if you intend to initialize in the `main` function 
WidgetsFlutterBinding.ensureInitialized();
Workmanager.initialize(

    // The top level function, aka callbackDispatcher 
    callbackDispatcher,

    // If enabled it will post a notification whenever 
    // the task is running. Handy for debugging tasks 
    isInDebugMode: true
 );
 // Periodic task registration 
 Workmanager.registerPeriodicTask(
    "2",

    //This is the value that will be 
    // returned in the callbackDispatcher 
    "simplePeriodicTask",

    // When no frequency is provided 
    // the default 15 minutes is set. 
    // Minimum frequency is 15 min. 
    // Android will automatically change 
    // your frequency to 15 min 
    // if you have configured a lower frequency. 
    frequency: Duration(minutes: 15),
  );
  runApp(MyApp());
  }

   void callbackDispatcher() {
 Workmanager.executeTask((task, inputData) {

    // initialise the plugin of flutterlocalnotifications. 
    FlutterLocalNotificationsPlugin flip = new  
    FlutterLocalNotificationsPlugin();

    // app_icon needs to be a added as a drawable 
    // resource to the Android head project. 
    var android = new AndroidInitializationSettings('@mipmap/ic_launcher');
    var IOS = new IOSInitializationSettings();

    // initialise settings for both Android and iOS device. 
    var settings = new InitializationSettings(android, IOS);
    flip.initialize(settings);
    _showNotificationWithDefaultSound(flip);
    return Future.value(true);
    });
   }

  Future _showNotificationWithDefaultSound(flip) async {

// Show a notification after every 15 minute with the first 
// appearance happening a minute after invoking the method 
var androidPlatformChannelSpecifics = new AndroidNotificationDetails(
        'your channel id',
'your channel name',
'your channel description',
importance: Importance.Max,
priority: Priority.High
);
var iOSPlatformChannelSpecifics = new IOSNotificationDetails();

// initialise channel platform for both Android and iOS device. 
var platformChannelSpecifics = new NotificationDetails(
        androidPlatformChannelSpecifics,
iOSPlatformChannelSpecifics
);
await flip.show(0, 'GeeksforGeeks',
'Your are one step away to connect with GeeksforGeeks',
platformChannelSpecifics, payload: 'Default_Sound'
);
}

class MyApp extends StatelessWidget {
// This widget is the root of your application. 
@override
Widget build(BuildContext context) {
    return MaterialApp(
        title: 'Geeks Demo',
    theme: ThemeData(

    // This is the theme 
    // of your application. 
    primarySwatch: Colors.green,
    ),
    home: HomePage(title: "GeeksforGeeks"),
    );
  }
  }

  class _HomePageState extends State<HomePage> {
@override
Widget build(BuildContext context) {

    // This method is rerun every time setState is called. 
    // The Flutter framework has been optimized 
    // to make rerunning build methods 
    // fast, so that you can just rebuild 
    // anything that needs updating rather 
    // than having to individually change 
    //instances of widgets. 
    return Scaffold(
        appBar: AppBar(

                // Here we take the value from 
                // the MyHomePage object that was created by 
                // the App.build method, and use it 
                // to set our appbar title. 
                title: Text(widget.title),
    ),
    body: new Container(),
    );
  }
  }

依赖性

dependencies:
    flutter:
    sdk: flutter
    
    # The following adds the Cupertino Icons font to your application.
    # Use with the CupertinoIcons class for iOS style icons.
    cupertino_icons: ^0.1.2
    # Use with the Workmanger class for background jobs headless execution.
    workmanager: ^0.2.3
    # Use with FlutterLocalNotificationsPlugin class for local push notifications.
    flutter_local_notifications: ^1.4.4+2

还有

<!-- Add below permission inside 'manifest' tag -->
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<!-- Add below permission inside 'application' tag -->
<receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
<action android:name="android.intent.action.MY_PACKAGE_REPLACED"/>
</intent-filter>
</receiver>

• 并用于更多

flutter_local_notifications
谢谢