问题
I know that the limit of local notifications is 64 for UILocalNotification. It's written in Apple Dev Docs. But UILocalNotification is deprecated in iOS 10. Instead this one, Apple proposes to use UNNotificationRequest. But Apple Dev Docs doesn't say anything about limiting the count of notifications. I found this answer, but it doesn't have links to Apple Dev Docs or something like that (it's just an opinion). Does anyone know for sure about restrictions of local notifications? Maybe someone know the link to Dev Docs or is there an official response from Apple about this?
回答1:
Although it's not officially documented, testing shows that UNNotificationRequest retains the 64 notification limit.
However, importantly, the way that they deal with the notification queue has changed. If there are more than 64 notifications:
UILocalNotificationwould keep the 64 soonest notificationsUNNotificationRequestkeeps the 64 last set notifications
This may be a bug, and is documented in this radar.
回答2:
The IOS 12 version of UNNotificationCenter.h has in comments of (void)addNotificationRequest:(UNNotificationRequest *)request withCompletionHandler:(nullable void(^)(NSError *__nullable error))completionHandler; this:
Notification requests can be scheduled to notify the user via time and location. See UNNotificationTrigger for more information. Calling -addNotificationRequest: will replace an existing notification request with the same identifier. A notification request with the identifier as an existing delivered notifications will alert for the new notification request and replace the existing delivered notification when it is triggered. The number of pending notification requests that may be scheduled by an application at any one time is limited by the system.
回答3:
Yes indeed, I just checked for iOS 10.2 and the limit for the total number of UNNotificationRequest you can add is still 64.
来源：https://stackoverflow.com/questions/43424044/limit-for-local-notifications-unnotificationrequest-in-ios-10