A background task used to update your app’s user interface in preparation for a snapshot.
- watchOS 3.0+
Using the methods of
WKSnapshot, you can push, pop, or present other interface controllers, and then update the content of the desired interface controller. The system automatically takes a snapshot of your user interface as soon as this task completes.
Do not subclass or create instances of this class. Instead, schedule a background snapshot refresh task by calling
schedule. When this task is triggered, the system launches your app in the background, instantiates a
WKSnapshot object, and passes the task object to your extension delegate’s
Background snapshot tasks are budgeted. In general, the system performs approximately one task per hour for each app in the dock (including the most recently used app). This budget is shared among all apps on the dock. The system performs multiple tasks an hour for each app with a complication on the active watch face. This budget is shared among all complications on the watch face. After you exhaust the budget, the system delays your requests until more time becomes available.
The system automatically schedules background snapshot request tasks in the following situations:
When your device starts up.
When your app updates the complication timeline.
When the user interacts with one of the apps notifications.
When the app transitions from the foreground to the background.
One hour after the user’s last interaction with the app. In this task, the
returnproperty is set to
To Glanceable UI
These requests do not cancel or replace any of your scheduled requests.