I'm diving into iOS development and am building my own alarm clock app to become familiar with the platform and SDK. One of the API's I'm currently learning is the Local Notifications API, which I assume is the same API Apple uses to implement their alarms in their Clock app.
What I don't understand is how they implement their "Snooze" functionality. As I understand it, Local Notifications allow you to present to the user an alert box that has at most two buttons when your app isn't running in the foreground, one button for dismissing the alert and one button for taking the user to your app. In Apple's Clock app, however, it appears the user is presented with an alert box with two buttons, one button to dismiss the alarm and one button to "Snooze" and reschedule the alarm without launching the Clock app. My questions are...
When the user clicks the "Snooze" button, how do you think Apple is rescheduling the Local Notification for the alarm without launching the Clock app? Do you think they're using their own private APIs that circumvent the limitations of the Local Notifications that only allow for two options? Or do you think they're launching the Clock app to reschedule the Local Notification, they just don't show the app launching and quitting?
The documentation says the "alertAction" property of the Local Notification is the text to be displayed on the right button of the alert box and the slider bar of the lock screen. In Apple's Clock app, however, the "Snooze" text is the left button in the alert box, nor is it the Slider bar text. Why is this backwards?
Thanks so much in advance for your thoughts!
The local notification API does not have any mechanism to do what you want. The alarm clock app is almost certainly not using any of the infrastructure for local notifications, it predates them. Even if it is factored onto some of the infrastructure provided by local notifications, it is certainly not using the public APIs.
You should file a bug requesting that this functionality be added.
来源：https://stackoverflow.com/questions/3441257/how-can-i-implement-apples-snooze-functionality-in-their-clock-app