如何在flutter和web api中推送通知

问题描述

我希望程序能够每分钟向服务器发送一个请求并返回一个列表： 我的清单： [{"NoteId": "Id","Title": "Note Title","Description": "Note Description","AtDateTime": "1/7/2021 10:10:15"}]

如果 AtDateTime 字段的值等于当前时间，则显示带有列表记录值的警报

我使用一个节点js来连接数据。 请帮帮我

解决方法

我找到了一个定期在后台执行任务的解决方案。
但这只会每 15 分钟发生一次

对于计划任务需要添加包：workmanager

对于本地通知添加包：flutter_local_notifications

 dependencies:
  flutter:
    sdk: flutter
....
  # Use with the Workmanger for background jobs headless execution.
  workmanager: ^0.2.3
  # Use with FlutterLocalNotificationsPlugin for local push notifications.
  flutter_local_notifications: ^1.4.4+2

将此代码添加到：-> android -> app -> src -> main -> AndroidManifest.xml

<!-- 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>

lib -> main.dart

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 HomePage extends StatefulWidget { 
HomePage({Key key,this.title}) : super(key: key); 

final String title; 

@override 
_HomePageState createState() => _HomePageState(); 
} 

class _HomePageState extends State<HomePage> { 
@override 
Widget build(BuildContext context) { 
    return Scaffold( 
    appBar: AppBar( 
        title: Text(widget.title),body: new Container(),); 
} 
}