Flutter中如何将用户选择的TimeOfDay应用到本地定时通知？

Alright, let's fix this so your notification triggers exactly at the time the user picks with the time picker. Here's how to adjust your code step by step:

1. Add a helper method to convert TimeOfDay to TZDateTime #

The zonedSchedule method requires a timezone-aware datetime (not just hours and minutes), so we need to turn the user's selected TimeOfDay into a full TZDateTime object. We also need to handle cases where the selected time has already passed today—we'll schedule it for tomorrow instead to avoid immediate, unintended triggers.

TZDateTime _convertTimeOfDayToTZDateTime(TimeOfDay selectedTime) {
  final now = tz.TZDateTime.now(tz.local);
  // Create a datetime for today at the selected hour/minute
  var scheduledDate = tz.TZDateTime(
    tz.local,
    now.year,
    now.month,
    now.day,
    selectedTime.hour,
    selectedTime.minute,
  );

  // If the selected time is already in the past today, use tomorrow's date
  if (scheduledDate.isBefore(now)) {
    scheduledDate = scheduledDate.add(const Duration(days: 1));
  }
  return scheduledDate;
}

2. Modify your notification scheduling method #

Replace your existing firstNotifications method with one that uses the converted datetime from the user's selection. I've renamed it to something more descriptive, and added optional title/body text since your original had null values (you can customize these as needed):

final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();
final mymodel = myModel();

Future<void> scheduleNotificationAtSelectedTime() async {
  // Initialize notifications as before
  var initializationSettingsAndroid = AndroidInitializationSettings('@mipmap/ic_launcher');
  var initializationSettings = InitializationSettings(android: initializationSettingsAndroid);
  await flutterLocalNotificationsPlugin.initialize(initializationSettings);

  // Keep your existing notification details
  const AndroidNotificationDetails firstNotificationSpecifics = AndroidNotificationDetails(
    'channel id',
    'channel name',
    'channel description',
    sound: RawResourceAndroidNotificationSound('song1'),
    playSound: true,
    enableVibration: false,
    visibility: NotificationVisibility.secret,
    autoCancel: true,
    timeoutAfter: 7000,
  );
  const NotificationDetails firstNotificationPlatformSpecifics = NotificationDetails(android: firstNotificationSpecifics);

  // Convert the user's selected TimeOfDay to a schedulable datetime
  final scheduledTime = _convertTimeOfDayToTZDateTime(mymodel.selectedTime);

  // Schedule the notification at the converted time
  await flutterLocalNotificationsPlugin.zonedSchedule(
    1,
    'Scheduled Reminder', // Customize notification title
    'Your notification is triggered at the time you selected!', // Customize notification body
    scheduledTime,
    firstNotificationPlatformSpecifics,
    uiLocalNotificationDateInterpretation: UILocalNotificationDateInterpretation.absoluteTime,
    androidAllowWhileIdle: true,
    // Uncomment this line if you want the notification to repeat daily at the same time
    // repeatInterval: RepeatInterval.daily,
  );
}

3. Trigger the schedule when the user selects a time #

Update your selectTime method to call the new scheduling function right after the user picks a time and saves it:

Future<Null> selectTime(BuildContext context) async {
  final picked = await showTimePicker(
    context: context,
    initialTime: model.selectedTime,
  );

  if (picked != null){
    setState(() {
      model.selectedTime = picked;
      this.preferences?.setString("dateValue", model.selectedTime.format(context));
      // Schedule the notification immediately after saving the selected time
      scheduleNotificationAtSelectedTime();
    });
  }
}

Key Notes: #

• Timezone Awareness: Using tz.TZDateTime ensures your notification works correctly across different timezones, which is crucial for reliable scheduling.
• Past Time Handling: The helper method checks if the selected time has already passed today—if so, it schedules for tomorrow instead of triggering instantly.
• Repeat Option: If you want the notification to repeat daily at the selected time, uncomment the repeatInterval line in the scheduling method.

内容的提问来源于stack exchange，提问作者kacola2115