xcode 每 30 分钟出现一次重复间隔问题
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/9162737/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Having issue with repeatinterval every 30 minutes
提问by Mc.Lover
I am trying to repeat a local notification every 30 minutes but my code does not work fine ... I would be grateful if you help me and find the solution , here is my code :
我试图每 30 分钟重复一次本地通知，但我的代码无法正常工作......如果您能帮助我并找到解决方案，我将不胜感激，这是我的代码：
UILocalNotification *reminderNote = [[UILocalNotification alloc]init];
reminderNote.fireDate = [NSDate dateWithTimeIntervalSinceNow:60 * 30];
reminderNote.repeatInterval = NSHourCalendarUnit;
reminderNote.alertBody = @"some text";
reminderNote.alertAction = @"View";
reminderNote.soundName = @"sound.aif";
[[UIApplication sharedApplication] scheduleLocalNotification:reminderNote];
回答by yuji
firedatesets the time that the notification fires the first time, and repeatIntervalis the interval between between repetitions of the notification. So the code in the question schedules a notification to fire 30 minutes (60 * 30 seconds) from now, and then repeat every hour.
firedate设置通知第一次触发的时间，repeatInterval是通知重复之间的间隔。因此，问题中的代码安排通知从现在开始 30 分钟（60 * 30 秒）触发，然后每小时重复一次。
Unfortunately, you can only schedule notifications to repeat at exact intervals defined by NSCalendar constants: e.g., every minute, every hour, every day, every month, but not at multiples of those intervals.
不幸的是，您只能安排通知以 NSCalendar常量定义的精确间隔重复：例如，每分钟、每小时、每天、每月，但不能以这些间隔的倍数重复。
Luckily, to get a notification every 30 minutes, you can just schedule two notifications: one right now, one 30 minutes from now, and have both repeat every hour. Like so:
幸运的是，要每 30 分钟收到一次通知，您只需安排两个通知：一个现在，一个 30 分钟后，并且每个小时重复一次。像这样：
UILocalNotification *reminderNote = [[UILocalNotification alloc]init];
reminderNote.fireDate = [NSDate dateWithTimeIntervalSinceNow:60 * 30];
reminderNote.repeatInterval = NSHourCalendarUnit;
reminderNote.alertBody = @"some text";
reminderNote.alertAction = @"View";
reminderNote.soundName = @"sound.aif";
[[UIApplication sharedApplication] scheduleLocalNotification:reminderNote];
reminderNote.fireDate = [NSDate dateWithTimeIntervalSinceNow:60 * 60];
[[UIApplication sharedApplication] scheduleLocalNotification:reminderNote];
