Flutter实现每3天触发本地通知功能遇阻求助

你的代码存在以下核心问题导致通知无法正常工作：

• 未触发检查逻辑：checkAndShowNotification方法从未被调用，初始化通知服务后没有执行任何检查或调度操作
• 仅前台检查无法满足后台推送：当前逻辑只有用户打开应用时才会检查时间，若用户3天不打开应用，通知不会触发
• Android通知渠道未创建：Android 8.0及以上系统需要显式创建通知渠道，否则通知无法显示
• 首次通知逻辑错误：首次打开应用时lastNotificationTime为null，会立即弹出通知，不符合“3天后推送”的需求

修复后的代码 #

notify_service.dart #

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

class NotificationService {
  final FlutterLocalNotificationsPlugin notificationsPlugin =
      FlutterLocalNotificationsPlugin();

  // 标记是否已设置重复通知
  Future<bool> _hasScheduledNotification() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    return prefs.getBool('hasScheduledNotification') ?? false;
  }

  Future<void> _setScheduledNotificationFlag(bool value) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.setBool('hasScheduledNotification', value);
  }

  // 创建Android通知渠道
  Future<void> _createAndroidNotificationChannel() async {
    const AndroidNotificationChannel channel = AndroidNotificationChannel(
      'repeat_notification_channel', // 渠道ID
      '重复提醒通知', // 渠道名称
      description: '每3天推送一次的用户提醒', // 渠道描述
      importance: Importance.max,
    );
    await notificationsPlugin.resolvePlatformSpecificImplementation<
            AndroidFlutterLocalNotificationsPlugin>()
        ?.createNotificationChannel(channel);
  }

  Future<void> initNotification() async {
    // Android初始化
    const AndroidInitializationSettings initializationSettingsAndroid =
        AndroidInitializationSettings('@drawable/sn_invent');

    // iOS初始化
    const DarwinInitializationSettings initializationSettingsIOS =
        DarwinInitializationSettings(
      requestAlertPermission: true,
      requestBadgePermission: true,
      requestSoundPermission: true,
    );

    const InitializationSettings initializationSettings =
        InitializationSettings(
      android: initializationSettingsAndroid,
      iOS: initializationSettingsIOS,
    );

    await notificationsPlugin.initialize(initializationSettings);
    // 创建Android通知渠道
    await _createAndroidNotificationChannel();
    // 检查并设置重复通知
    await _setupRepeatingNotification();
  }

  NotificationDetails _notificationDetails() {
    return const NotificationDetails(
      android: AndroidNotificationDetails(
        'repeat_notification_channel',
        '重复提醒通知',
        channelDescription: '每3天推送一次的用户提醒',
        importance: Importance.max,
        priority: Priority.high,
      ),
      iOS: DarwinNotificationDetails(),
    );
  }

  // 设置每3天重复的通知
  Future<void> _setupRepeatingNotification() async {
    bool hasScheduled = await _hasScheduledNotification();
    if (hasScheduled) return;

    // 首次通知时间：当前时间+3天
    DateTime firstNotificationTime = DateTime.now().add(const Duration(days: 3));

    // 调度重复通知
    await notificationsPlugin.periodicallyShow(
      0, // 通知ID
      '您的应用提醒',
      '该打开应用看看啦！',
      RepeatInterval.everyThreeDays, // 每3天重复
      _notificationDetails(),
      androidAllowWhileIdle: true, // 允许设备空闲时触发
      uiLocalNotificationDateInterpretation:
          UILocalNotificationDateInterpretation.absoluteTime,
    );

    // 标记已设置重复通知
    await _setScheduledNotificationFlag(true);
  }
}

main.dart #

import 'package:flutter/material.dart';
import 'package:flutter_goals_application/src/services/notify_service.dart';
import 'screens/homescreen.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  NotificationService notificationService = NotificationService();
  await notificationService.initNotification();
  runApp(const MaterialApp(
    home: HomescreenWidget(),
  ));
}

关键修改说明 #

1. 使用系统级重复调度：通过periodicallyShow方法让系统负责调度通知，即使应用关闭或在后台也能按时触发
2. 添加通知渠道创建逻辑：适配Android 8.0+的通知渠道要求，确保通知能正常显示
3. 避免重复调度：用SharedPreferences标记是否已设置重复通知，防止每次打开应用都重新创建调度任务
4. 修正首次通知时间：首次通知设置为当前时间+3天，而不是立即触发
5. 优化Android触发条件：设置androidAllowWhileIdle: true，确保设备低功耗时也能触发通知

内容的提问来源于stack exchange，提问作者user19922759