当 Hive 数据在 FireBaseMessage 的 onBackgroundMessage 处理程序中更新时，如何更新 UI 小部件？
How can I update the UI widget when Hive data get update inside onBackgroundMessage handler of FireBaseMessage in flutter?
我正在开发一个应用程序，它可以接收来自 firebase 云消息传递的通知。我在收到消息后将其保存在 Hive 中。我有一个通知屏幕，显示从配置单元读取的通知，收到通知后会立即更新。这一直运作良好。
现在的问题是，当应用程序在后台 运行（而不是 kill/terminate）时收到的通知被保存在配置单元中，但是当导航到通知屏幕时屏幕没有更新（更新在在应用程序终止并重新运行之前，看不到配置单元。
我读到这是因为 onBackgroundMessage 处理程序运行在不同的 isolate 上，而 isolate 不能共享存储。看来我需要一种方法将 Hive 通知更新从 onBackgroundMessage 处理程序传递到主隔离区。
这是我目前的实现
push_message.dart通知class实例保存在hive
import 'dart:convert';
import 'package:dio/dio.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:app_name/helpers/helpers.dart';
part 'push_message.g.dart';
@HiveType(typeId: 1)
class PushMessage extends HiveObject {
@HiveField(0)
int id = int.parse(generateRandomNumber(7));
@HiveField(1)
String? messageId;
@HiveField(2)
String title;
@HiveField(3)
String body;
@HiveField(4)
String? bigPicture;
@HiveField(5)
DateTime? sentAt;
@HiveField(6)
DateTime? receivedAt;
@HiveField(7)
String? payload;
@HiveField(8, defaultValue: '')
String channelId = 'channel_id';
@HiveField(9, defaultValue: 'channel name')
String channelName = 'channel name';
@HiveField(10, defaultValue: 'App notification')
String channelDescription = 'App notification';
PushMessage({
this.id = 0,
this.messageId,
required this.title,
required this.body,
this.payload,
this.channelDescription = 'App notification',
this.channelName = 'channel name',
this.channelId = 'channel_id',
this.bigPicture,
this.sentAt,
this.receivedAt,
});
Future<void> display() async {
AndroidNotificationDetails androidPlatformChannelSpecifics =
AndroidNotificationDetails(
channelId,
channelName,
channelDescription: channelDescription,
importance: Importance.max,
priority: Priority.high,
ticker: 'ticker',
icon: "app_logo",
largeIcon: DrawableResourceAndroidBitmap('app_logo'),
);
IOSNotificationDetails iOS = IOSNotificationDetails(
presentAlert: true,
);
NotificationDetails platformChannelSpecifics =
NotificationDetails(android: androidPlatformChannelSpecifics, iOS: iOS);
final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
FlutterLocalNotificationsPlugin();
await flutterLocalNotificationsPlugin
.show(id, title, body, platformChannelSpecifics, payload: payload);
}
Map<String, dynamic> toMap() {
return {
'id': id,
'messageId': messageId,
'title': title,
'body': body,
'bigPicture': bigPicture,
'sentAt': sentAt?.millisecondsSinceEpoch,
'receivedAt': receivedAt?.millisecondsSinceEpoch,
'payload': payload,
};
}
factory PushMessage.fromMap(map) {
return PushMessage(
id: map.hashCode,
messageId: map['messageId'],
title: map['title'],
body: map['body'],
payload: map['payload'],
bigPicture: map['bigPicture'],
sentAt: map['sentAt'] is DateTime
? map['sentAt']
: (map['sentAt'] is int
? DateTime.fromMillisecondsSinceEpoch(map['sentAt'])
: null),
receivedAt: map['receivedAt'] is DateTime
? map['receivedAt']
: (map['receivedAt'] is int
? DateTime.fromMillisecondsSinceEpoch(map['receivedAt'])
: null),
);
}
factory PushMessage.fromFCM(RemoteMessage event) {
RemoteNotification? notification = event.notification;
Map<String, dynamic> data = event.data;
var noti = PushMessage(
id: event.hashCode,
messageId: event.messageId!,
title: notification?.title ?? (data['title'] ?? 'No title found'),
body: notification?.body! ?? (data['body'] ?? 'Can not find content'),
sentAt: event.sentTime,
receivedAt: DateTime.now(),
bigPicture: event.notification?.android?.imageUrl,
);
return noti;
}
Future<void> saveToHive() async {
if (!Hive.isBoxOpen('notifications')) {
await Hive.openBox<PushMessage>('notifications');
}
await Hive.box<PushMessage>('notifications').add(this);
}
String toJson() => json.encode(toMap());
factory PushMessage.fromJson(String source) =>
PushMessage.fromMap(json.decode(source));
Future<void> sendToOne(String receiverToken) async {
try {
await Dio().post(
"https://fcm.googleapis.com/fcm/send",
data: {
"to": receiverToken,
"data": {
"url": bigPicture,
"title": title,
"body": body,
"mutable_content": true,
"sound": "Tri-tone"
}
},
options: Options(
contentType: 'application/json; charset=UTF-8',
headers: {
"Authorization":
"Bearer xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
},
),
);
} catch (e) {
debugPrint("Error sending notification");
debugPrint(e.toString());
}
}
}
notifications.dart 通知屏幕
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:app_name/custom_widgets/drawer_sheet.dart';
import 'package:app_name/custom_widgets/notification_expandable.dart';
import 'package:app_name/models/config.dart';
import 'package:app_name/models/push_message.dart';
class Notifications extends StatelessWidget {
const Notifications({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
if (!Hive.isBoxOpen('notifications')) {
Hive.openBox<PushMessage>('notifications');
}
return Scaffold(
appBar: AppBar(
title: const Text("Notifications"),
centerTitle: true,
),
body: ValueListenableBuilder<Box<PushMessage>>(
valueListenable: Hive.box<PushMessage>('notifications').listenable(),
builder: (context, Box<PushMessage> box, widget) {
return box.isEmpty
? const Center(child: Text('Empty'))
: ListView.builder(
itemCount: box.length,
itemBuilder: (BuildContext context, int i) {
int reversedIndex = box.length - i - 1;
return NotificationExpandable((box.getAt(reversedIndex))!);
},
);
},
),
drawer: !useDrawer
? null
: const DrawerSheet(
currentPage: "notifications",
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Hive.box<PushMessage>('notifications').clear();
},
child: const Text('Clear'),
),
);
}
}
backgroundMessageHandler
Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
if (!Hive.isAdapterRegistered(1)) {
Hive.registerAdapter(PushMessageAdapter());
}
await Hive.initFlutter();
if (!Hive.isBoxOpen('notifications')) {
await Hive.openBox<PushMessage>('notifications');
}
await Firebase.initializeApp();
print('Handling a background message ${message.messageId}');
PushMessage msg = PushMessage.fromFCM(message);
await msg.saveToHive();
msg.display();
Hive.close();
}
我找到了解决方法。
无法从 firebase 云消息传递的 onBackgroundMessage 处理程序与主隔离区进行通信，因为该函数在不同的隔离区上运行，我不知道它是在哪里触发的。 FCM 文档还说，任何 UI 影响逻辑都不能在此处理程序中完成，但 io 过程（如将消息存储在设备存储中）是可能的。
我将背景消息保存在与我保存前景消息的位置不同的配置单元框中。因此，在通知屏幕的初始状态，我首先从背景框获取消息，将其附加到前景框，然后启动一个在隔离中运行的函数，每 1 秒检查一次表单背景消息。当该函数获得后台消息时，它会将主隔离区作为映射发送给它，在那里它被转换为前景消息的实例并附加到前景消息框。每当前景通知框的值发生变化时，小部件就会更新，因为我使用了一个 ValueListenableBuilder 来侦听前景通知的配置单元框。然后隔离在屏幕的处置方法中终止。
这是代码。
import 'dart:async';
import 'dart:isolate';
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:path_provider/path_provider.dart';
import 'package:app_name/custom_widgets/drawer_sheet.dart';
import 'package:app_name/custom_widgets/notification_expandable.dart';
import 'package:app_name/models/background_push_message.dart';
import 'package:app_name/models/config.dart';
import 'package:app_name/models/push_message.dart';
class Notifications extends StatefulWidget {
const Notifications({Key? key}) : super(key: key);
@override
State<Notifications> createState() => _NotificationsState();
}
class _NotificationsState extends State<Notifications> {
bool loading = true;
late Box<PushMessage> notifications;
@override
void dispose() {
stopRunningIsolate();
super.dispose();
}
@override
void initState() {
super.initState();
startIsolate().then((value) {
setState(() {
loading = false;
});
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text("Notifications"),
centerTitle: true,
),
body: ValueListenableBuilder<Box<PushMessage>>(
valueListenable: Hive.box<PushMessage>('notifications').listenable(),
builder: (context, Box<PushMessage> box, widget) {
return box.isEmpty
? const Center(child: Text('Empty'))
: ListView.builder(
itemCount: box.length,
itemBuilder: (BuildContext context, int i) {
int reversedIndex = box.length - i - 1;
return NotificationExpandable((box.getAt(reversedIndex))!);
},
);
},
),
drawer: fromSchool
? null
: const DrawerSheet(
currentPage: "notifications",
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Hive.box<PushMessage>('notifications').clear();
},
child: const Text('Clear'),
),
);
}
}
Isolate? isolate;
Future<bool> startIsolate() async {
if (!Hive.isAdapterRegistered(2)) {
Hive.registerAdapter(BackgroundPushMessageAdapter());
}
Hive.initFlutter();
if (!Hive.isBoxOpen('notifications')) {
await Hive.openBox<PushMessage>('notifications');
}
if (Hive.isBoxOpen('background_notifications')) {
await Hive.box<BackgroundPushMessage>('background_notifications').close();
}
await Hive.openBox<BackgroundPushMessage>('background_notifications');
Iterable<BackgroundPushMessage> bgNotifications =
Hive.box<BackgroundPushMessage>('background_notifications').values;
List<PushMessage> bgMsgs =
bgNotifications.map((e) => PushMessage.fromMap(e.toMap())).toList();
Hive.box<PushMessage>('notifications').addAll(bgMsgs);
await Hive.box<BackgroundPushMessage>('background_notifications').clear();
await Hive.box<BackgroundPushMessage>('background_notifications').close();
ReceivePort receivePort = ReceivePort();
String path = (await getApplicationDocumentsDirectory()).path;
isolate = await Isolate.spawn(
backgroundNotificationCheck, [receivePort.sendPort, path]);
receivePort.listen((msg) {
List<Map> data = msg as List<Map>;
List<PushMessage> notis =
data.map((noti) => PushMessage.fromMap(noti)).toList();
Hive.box<PushMessage>('notifications').addAll(notis);
});
return true;
}
void stopRunningIsolate() {
isolate?.kill(priority: Isolate.immediate);
isolate = null;
}
Future<void> backgroundNotificationCheck(List args) async {
SendPort sendPort = args[0];
String path = args[1];
if (!Hive.isAdapterRegistered(1)) {
Hive.registerAdapter(PushMessageAdapter());
}
Hive.init(path);
Timer.periodic(const Duration(seconds: 1), (Timer t) async {
if (!Hive.isAdapterRegistered(2)) {
Hive.registerAdapter(BackgroundPushMessageAdapter());
}
if (Hive.isBoxOpen('background_notifications')) {
await Hive.box<BackgroundPushMessage>('background_notifications').close();
}
await Hive.openBox<BackgroundPushMessage>('background_notifications');
if (Hive.box<BackgroundPushMessage>('background_notifications')
.isNotEmpty) {
List<Map> notifications =
Hive.box<BackgroundPushMessage>('background_notifications')
.values
.map((noti) => noti.toMap())
.toList();
sendPort.send(notifications);
await Hive.box<BackgroundPushMessage>('background_notifications').clear();
}
await Hive.box<BackgroundPushMessage>('background_notifications').close();
});
}
onBackgroundNotification 处理程序
if (!Hive.isAdapterRegistered(2)) {
Hive.registerAdapter(BackgroundPushMessageAdapter());
}
final documentDirectory = await getApplicationDocumentsDirectory();
Hive.init(documentDirectory.path);
if (Hive.isBoxOpen('background_notifications')) {
await Hive.box<BackgroundPushMessage>('background_notifications').close();
}
await Hive.openBox<BackgroundPushMessage>('background_notifications');
await Firebase.initializeApp();
print('Handling a background message ${message.messageId}');
BackgroundPushMessage msg = BackgroundPushMessage.fromFCM(message);
msg.display();
Hive.box<BackgroundPushMessage>('background_notifications').add(msg);
print("Notification shown for $msg");
print(
"Notification length ${Hive.box<BackgroundPushMessage>('background_notifications').length}");
if (Hive.isBoxOpen('background_notifications')) {
Hive.box<BackgroundPushMessage>('background_notifications').close();
}
请注意，我对后台通知对象和前台通知对象有不同的 class，因为配置单元无法在不同的框中注册相同 class 的两个实例。因此，我必须为每个 class 注册适配器。不过，我让一个 class 扩展了另一个以避免重复代码。
我正在开发一个应用程序，它可以接收来自 firebase 云消息传递的通知。我在收到消息后将其保存在 Hive 中。我有一个通知屏幕，显示从配置单元读取的通知，收到通知后会立即更新。这一直运作良好。
现在的问题是，当应用程序在后台 运行（而不是 kill/terminate）时收到的通知被保存在配置单元中，但是当导航到通知屏幕时屏幕没有更新（更新在在应用程序终止并重新运行之前，看不到配置单元。
我读到这是因为 onBackgroundMessage 处理程序运行在不同的 isolate 上，而 isolate 不能共享存储。看来我需要一种方法将 Hive 通知更新从 onBackgroundMessage 处理程序传递到主隔离区。
这是我目前的实现
push_message.dart通知class实例保存在hive
import 'dart:convert';
import 'package:dio/dio.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:app_name/helpers/helpers.dart';
part 'push_message.g.dart';
@HiveType(typeId: 1)
class PushMessage extends HiveObject {
@HiveField(0)
int id = int.parse(generateRandomNumber(7));
@HiveField(1)
String? messageId;
@HiveField(2)
String title;
@HiveField(3)
String body;
@HiveField(4)
String? bigPicture;
@HiveField(5)
DateTime? sentAt;
@HiveField(6)
DateTime? receivedAt;
@HiveField(7)
String? payload;
@HiveField(8, defaultValue: '')
String channelId = 'channel_id';
@HiveField(9, defaultValue: 'channel name')
String channelName = 'channel name';
@HiveField(10, defaultValue: 'App notification')
String channelDescription = 'App notification';
PushMessage({
this.id = 0,
this.messageId,
required this.title,
required this.body,
this.payload,
this.channelDescription = 'App notification',
this.channelName = 'channel name',
this.channelId = 'channel_id',
this.bigPicture,
this.sentAt,
this.receivedAt,
});
Future<void> display() async {
AndroidNotificationDetails androidPlatformChannelSpecifics =
AndroidNotificationDetails(
channelId,
channelName,
channelDescription: channelDescription,
importance: Importance.max,
priority: Priority.high,
ticker: 'ticker',
icon: "app_logo",
largeIcon: DrawableResourceAndroidBitmap('app_logo'),
);
IOSNotificationDetails iOS = IOSNotificationDetails(
presentAlert: true,
);
NotificationDetails platformChannelSpecifics =
NotificationDetails(android: androidPlatformChannelSpecifics, iOS: iOS);
final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
FlutterLocalNotificationsPlugin();
await flutterLocalNotificationsPlugin
.show(id, title, body, platformChannelSpecifics, payload: payload);
}
Map<String, dynamic> toMap() {
return {
'id': id,
'messageId': messageId,
'title': title,
'body': body,
'bigPicture': bigPicture,
'sentAt': sentAt?.millisecondsSinceEpoch,
'receivedAt': receivedAt?.millisecondsSinceEpoch,
'payload': payload,
};
}
factory PushMessage.fromMap(map) {
return PushMessage(
id: map.hashCode,
messageId: map['messageId'],
title: map['title'],
body: map['body'],
payload: map['payload'],
bigPicture: map['bigPicture'],
sentAt: map['sentAt'] is DateTime
? map['sentAt']
: (map['sentAt'] is int
? DateTime.fromMillisecondsSinceEpoch(map['sentAt'])
: null),
receivedAt: map['receivedAt'] is DateTime
? map['receivedAt']
: (map['receivedAt'] is int
? DateTime.fromMillisecondsSinceEpoch(map['receivedAt'])
: null),
);
}
factory PushMessage.fromFCM(RemoteMessage event) {
RemoteNotification? notification = event.notification;
Map<String, dynamic> data = event.data;
var noti = PushMessage(
id: event.hashCode,
messageId: event.messageId!,
title: notification?.title ?? (data['title'] ?? 'No title found'),
body: notification?.body! ?? (data['body'] ?? 'Can not find content'),
sentAt: event.sentTime,
receivedAt: DateTime.now(),
bigPicture: event.notification?.android?.imageUrl,
);
return noti;
}
Future<void> saveToHive() async {
if (!Hive.isBoxOpen('notifications')) {
await Hive.openBox<PushMessage>('notifications');
}
await Hive.box<PushMessage>('notifications').add(this);
}
String toJson() => json.encode(toMap());
factory PushMessage.fromJson(String source) =>
PushMessage.fromMap(json.decode(source));
Future<void> sendToOne(String receiverToken) async {
try {
await Dio().post(
"https://fcm.googleapis.com/fcm/send",
data: {
"to": receiverToken,
"data": {
"url": bigPicture,
"title": title,
"body": body,
"mutable_content": true,
"sound": "Tri-tone"
}
},
options: Options(
contentType: 'application/json; charset=UTF-8',
headers: {
"Authorization":
"Bearer xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
},
),
);
} catch (e) {
debugPrint("Error sending notification");
debugPrint(e.toString());
}
}
}
notifications.dart 通知屏幕
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:app_name/custom_widgets/drawer_sheet.dart';
import 'package:app_name/custom_widgets/notification_expandable.dart';
import 'package:app_name/models/config.dart';
import 'package:app_name/models/push_message.dart';
class Notifications extends StatelessWidget {
const Notifications({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
if (!Hive.isBoxOpen('notifications')) {
Hive.openBox<PushMessage>('notifications');
}
return Scaffold(
appBar: AppBar(
title: const Text("Notifications"),
centerTitle: true,
),
body: ValueListenableBuilder<Box<PushMessage>>(
valueListenable: Hive.box<PushMessage>('notifications').listenable(),
builder: (context, Box<PushMessage> box, widget) {
return box.isEmpty
? const Center(child: Text('Empty'))
: ListView.builder(
itemCount: box.length,
itemBuilder: (BuildContext context, int i) {
int reversedIndex = box.length - i - 1;
return NotificationExpandable((box.getAt(reversedIndex))!);
},
);
},
),
drawer: !useDrawer
? null
: const DrawerSheet(
currentPage: "notifications",
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Hive.box<PushMessage>('notifications').clear();
},
child: const Text('Clear'),
),
);
}
}
backgroundMessageHandler
Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
if (!Hive.isAdapterRegistered(1)) {
Hive.registerAdapter(PushMessageAdapter());
}
await Hive.initFlutter();
if (!Hive.isBoxOpen('notifications')) {
await Hive.openBox<PushMessage>('notifications');
}
await Firebase.initializeApp();
print('Handling a background message ${message.messageId}');
PushMessage msg = PushMessage.fromFCM(message);
await msg.saveToHive();
msg.display();
Hive.close();
}
我找到了解决方法。
无法从 firebase 云消息传递的 onBackgroundMessage 处理程序与主隔离区进行通信，因为该函数在不同的隔离区上运行，我不知道它是在哪里触发的。 FCM 文档还说，任何 UI 影响逻辑都不能在此处理程序中完成，但 io 过程（如将消息存储在设备存储中）是可能的。
我将背景消息保存在与我保存前景消息的位置不同的配置单元框中。因此，在通知屏幕的初始状态，我首先从背景框获取消息，将其附加到前景框，然后启动一个在隔离中运行的函数，每 1 秒检查一次表单背景消息。当该函数获得后台消息时，它会将主隔离区作为映射发送给它，在那里它被转换为前景消息的实例并附加到前景消息框。每当前景通知框的值发生变化时，小部件就会更新，因为我使用了一个 ValueListenableBuilder 来侦听前景通知的配置单元框。然后隔离在屏幕的处置方法中终止。 这是代码。
import 'dart:async';
import 'dart:isolate';
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:path_provider/path_provider.dart';
import 'package:app_name/custom_widgets/drawer_sheet.dart';
import 'package:app_name/custom_widgets/notification_expandable.dart';
import 'package:app_name/models/background_push_message.dart';
import 'package:app_name/models/config.dart';
import 'package:app_name/models/push_message.dart';
class Notifications extends StatefulWidget {
const Notifications({Key? key}) : super(key: key);
@override
State<Notifications> createState() => _NotificationsState();
}
class _NotificationsState extends State<Notifications> {
bool loading = true;
late Box<PushMessage> notifications;
@override
void dispose() {
stopRunningIsolate();
super.dispose();
}
@override
void initState() {
super.initState();
startIsolate().then((value) {
setState(() {
loading = false;
});
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text("Notifications"),
centerTitle: true,
),
body: ValueListenableBuilder<Box<PushMessage>>(
valueListenable: Hive.box<PushMessage>('notifications').listenable(),
builder: (context, Box<PushMessage> box, widget) {
return box.isEmpty
? const Center(child: Text('Empty'))
: ListView.builder(
itemCount: box.length,
itemBuilder: (BuildContext context, int i) {
int reversedIndex = box.length - i - 1;
return NotificationExpandable((box.getAt(reversedIndex))!);
},
);
},
),
drawer: fromSchool
? null
: const DrawerSheet(
currentPage: "notifications",
),
floatingActionButton: FloatingActionButton(
onPressed: () {
Hive.box<PushMessage>('notifications').clear();
},
child: const Text('Clear'),
),
);
}
}
Isolate? isolate;
Future<bool> startIsolate() async {
if (!Hive.isAdapterRegistered(2)) {
Hive.registerAdapter(BackgroundPushMessageAdapter());
}
Hive.initFlutter();
if (!Hive.isBoxOpen('notifications')) {
await Hive.openBox<PushMessage>('notifications');
}
if (Hive.isBoxOpen('background_notifications')) {
await Hive.box<BackgroundPushMessage>('background_notifications').close();
}
await Hive.openBox<BackgroundPushMessage>('background_notifications');
Iterable<BackgroundPushMessage> bgNotifications =
Hive.box<BackgroundPushMessage>('background_notifications').values;
List<PushMessage> bgMsgs =
bgNotifications.map((e) => PushMessage.fromMap(e.toMap())).toList();
Hive.box<PushMessage>('notifications').addAll(bgMsgs);
await Hive.box<BackgroundPushMessage>('background_notifications').clear();
await Hive.box<BackgroundPushMessage>('background_notifications').close();
ReceivePort receivePort = ReceivePort();
String path = (await getApplicationDocumentsDirectory()).path;
isolate = await Isolate.spawn(
backgroundNotificationCheck, [receivePort.sendPort, path]);
receivePort.listen((msg) {
List<Map> data = msg as List<Map>;
List<PushMessage> notis =
data.map((noti) => PushMessage.fromMap(noti)).toList();
Hive.box<PushMessage>('notifications').addAll(notis);
});
return true;
}
void stopRunningIsolate() {
isolate?.kill(priority: Isolate.immediate);
isolate = null;
}
Future<void> backgroundNotificationCheck(List args) async {
SendPort sendPort = args[0];
String path = args[1];
if (!Hive.isAdapterRegistered(1)) {
Hive.registerAdapter(PushMessageAdapter());
}
Hive.init(path);
Timer.periodic(const Duration(seconds: 1), (Timer t) async {
if (!Hive.isAdapterRegistered(2)) {
Hive.registerAdapter(BackgroundPushMessageAdapter());
}
if (Hive.isBoxOpen('background_notifications')) {
await Hive.box<BackgroundPushMessage>('background_notifications').close();
}
await Hive.openBox<BackgroundPushMessage>('background_notifications');
if (Hive.box<BackgroundPushMessage>('background_notifications')
.isNotEmpty) {
List<Map> notifications =
Hive.box<BackgroundPushMessage>('background_notifications')
.values
.map((noti) => noti.toMap())
.toList();
sendPort.send(notifications);
await Hive.box<BackgroundPushMessage>('background_notifications').clear();
}
await Hive.box<BackgroundPushMessage>('background_notifications').close();
});
}
onBackgroundNotification 处理程序
if (!Hive.isAdapterRegistered(2)) {
Hive.registerAdapter(BackgroundPushMessageAdapter());
}
final documentDirectory = await getApplicationDocumentsDirectory();
Hive.init(documentDirectory.path);
if (Hive.isBoxOpen('background_notifications')) {
await Hive.box<BackgroundPushMessage>('background_notifications').close();
}
await Hive.openBox<BackgroundPushMessage>('background_notifications');
await Firebase.initializeApp();
print('Handling a background message ${message.messageId}');
BackgroundPushMessage msg = BackgroundPushMessage.fromFCM(message);
msg.display();
Hive.box<BackgroundPushMessage>('background_notifications').add(msg);
print("Notification shown for $msg");
print(
"Notification length ${Hive.box<BackgroundPushMessage>('background_notifications').length}");
if (Hive.isBoxOpen('background_notifications')) {
Hive.box<BackgroundPushMessage>('background_notifications').close();
}
请注意，我对后台通知对象和前台通知对象有不同的 class，因为配置单元无法在不同的框中注册相同 class 的两个实例。因此，我必须为每个 class 注册适配器。不过，我让一个 class 扩展了另一个以避免重复代码。