flutter 通过 workManager 安排本地通知

Question

Is it possible to schedule notification from background dart code?

For example, like using work_manager plugin from executeTask method as if I register service that runs every hour and schedule today notification base on current location.

I tried out but no luck.

Can anyone help me with that?

Answer 1

Yes, it is possible to schedule Local notification with the help of work manager. When I was trying the Flutter Local Notification Plugin on my Xiaomi device, the notification is not showing when the app is closed ( and cleared from the recent activity). So the only solution I found was to use the Work Manager flutter plugin to show() directly without scheduling.

PROS

• Work Manager helped me to show notifications after the app closed and cleared from the recent app list.
• It will work even after the device restart

CONS

• The notification will not show up sometimes.
• The scheduling to fixed time cannot be managed. (android sometimes does not allow to execute task if the app is closed)

callbackDispatcher() {
Workmanager.executeTask((task, inputData) async {
if (LocalNotification.flutterNotificationPlugin == null) {
await LocalNotification.Initializer();
}
DateTime now = DateTime.now();
var hour = inputData['hour'];
var minute = inputData['minute'];
DateTime time = DateTime(now.year, now.month, now.day, now.hour, minute);
await LocalNotification.ShowOneTimeNotification(time);
return Future.value(true);
});
}

Trigger

FlatButton(
child: Text('set'),
onPressed: () async {
await Workmanager.initialize(callbackDispatcher);
await Workmanager.registerPeriodicTask(
"test_workertask", "test_workertask",
inputData: {"data1": "value1", "data2": "value2"},
frequency: Duration(hours: 1),
initialDelay: Duration(seconds: 10),
existingWorkPolicy: ExistingWorkPolicy.replace);
},
),

Answer 2

You can try with flutter_local_notifications by reusing snippet below:

import 'dart:async';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';

var duration = Duration(hours: 1);
var scheduledNotificationDateTime = DateTime.now().add(duration);

var androidPlatformChannelSpecifics = AndroidNotificationDetails(
    'your other channel id',
    'your other channel name', 
    'your other channel description',
);

var iOSPlatformChannelSpecifics = IOSNotificationDetails();

NotificationDetails platformChannelSpecifics = NotificationDetails(
   androidPlatformChannelSpecifics, 
   iOSPlatformChannelSpecifics,
);

await flutterLocalNotificationsPlugin.schedule(
    0, 
    'scheduled title', 
    'scheduled body', 
    scheduledNotificationDateTime, 
    platformChannelSpecifics,
);

Answer 3

In order schedule notifications work you should add lines below. Solution is this: add these lines after </activity> in AndroidManifest.xml:

<receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
    </intent-filter>
    </receiver>
    <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />