如何用Flutter实现特定时段内每2小时发送提醒通知？

不管用flutter_local_notifications还是awesome_notifications，都能实现你要的时间段内定时提醒功能，以下是具体实现思路和代码示例：

方案一：使用flutter_local_notifications #

这个插件依赖系统原生通知调度，稳定性较好，适合基础定时需求。

步骤1：初始化插件 #

先完成插件的初始化和基础配置（iOS需在Info.plist添加通知权限描述，Android无需额外权限）：

final FlutterLocalNotificationsPlugin _notificationsPlugin = FlutterLocalNotificationsPlugin();

Future<void> initNotifications() async {
  const AndroidInitializationSettings androidSettings =
      AndroidInitializationSettings('@mipmap/ic_launcher');
  const DarwinInitializationSettings iosSettings = DarwinInitializationSettings();
  const InitializationSettings initSettings = InitializationSettings(
    android: androidSettings,
    iOS: iosSettings,
  );
  await _notificationsPlugin.initialize(initSettings);
}

步骤2：安排每日重复通知 #

核心思路是生成时间段内所有触发时间点，为每个时间点创建每日重复的单次通知：

Future<void> setupWaterReminders(TimeOfDay startTime, TimeOfDay endTime, int intervalHours) async {
  // 先清除旧的通知，避免重复
  await _notificationsPlugin.cancelAll();

  final today = DateTime.now();
  final startDateTime = DateTime(today.year, today.month, today.day, startTime.hour, startTime.minute);
  final endDateTime = DateTime(today.year, today.month, today.day, endTime.hour, endTime.minute);

  // 生成当天所有触发时间
  List<DateTime> triggerTimes = [];
  DateTime current = startDateTime;
  while (current.isBefore(endDateTime) || current.isAtSameMomentAs(endDateTime)) {
    triggerTimes.add(current);
    current = current.add(Duration(hours: intervalHours));
  }

  // 配置通知样式
  const AndroidNotificationDetails androidDetails = AndroidNotificationDetails(
    'water_reminder',
    '喝水提醒',
    channelDescription: '定时提醒补充水分',
    importance: Importance.high,
    priority: Priority.high,
  );
  const NotificationDetails notificationDetails = NotificationDetails(android: androidDetails);

  // 为每个时间点安排每日重复通知
  for (int i = 0; i < triggerTimes.length; i++) {
    await _notificationsPlugin.showDailyAtTime(
      i, // 每个通知唯一ID
      '该喝水啦！',
      '起身喝一杯水，保持身体水分充足',
      Time(triggerTimes[i].hour, triggerTimes[i].minute),
      notificationDetails,
    );
  }
}

方案二：使用awesome_notifications #

这个插件提供更灵活的调度规则，支持复杂场景的时间配置。

步骤1：初始化插件并请求权限 #

import 'package:awesome_notifications/awesome_notifications.dart';

Future<void> initAwesomeNotifications() async {
  await AwesomeNotifications().initialize(
    '@mipmap/ic_launcher', // 通知图标路径
    [
      NotificationChannel(
        channelKey: 'water_reminder_channel',
        channelName: '喝水提醒',
        channelDescription: '定时提醒喝水',
        importance: NotificationImportance.High,
      )
    ],
  );

  // 请求通知权限（必须步骤）
  await AwesomeNotifications().requestPermissionToSendNotifications();
}

步骤2：创建每日重复通知 #

先清除旧通知，再生成时间段内的触发点，配置每日重复：

Future<void> setupWaterReminders(TimeOfDay startTime, TimeOfDay endTime, int intervalHours) async {
  // 清除所有旧通知
  await AwesomeNotifications().cancelAllNotifications();

  final today = DateTime.now();
  final startDateTime = DateTime(today.year, today.month, today.day, startTime.hour, startTime.minute);
  final endDateTime = DateTime(today.year, today.month, today.day, endTime.hour, endTime.minute);

  DateTime current = startDateTime;
  while (current.isBefore(endDateTime) || current.isAtSameMomentAs(endDateTime)) {
    await AwesomeNotifications().createNotification(
      content: NotificationContent(
        id: current.hour * 60 + current.minute, // 用时间作为唯一ID
        channelKey: 'water_reminder_channel',
        title: '该喝水啦！',
        body: '记得补充水分哦',
      ),
      schedule: NotificationCalendar(
        hour: current.hour,
        minute: current.minute,
        repeats: true, // 每日重复
      ),
    );
    current = current.add(Duration(hours: intervalHours));
  }
}

关键注意事项 #

• 权限与后台限制：iOS需在Info.plist添加NSUserNotificationUsageDescription和NSForegroundUsageDescription；Android部分厂商的后台省电策略会影响通知触发，建议引导用户关闭对应应用的省电模式。
• 更新时间段：用户修改起止时间后，必须先清除旧通知，再重新安排新通知，避免重复提醒。
• 通知ID唯一性：每个通知的ID必须唯一，否则会覆盖之前的通知。

内容的提问来源于stack exchange，提问作者Thanongsak