Posted by UIKit when VoiceOver starts or stops.
- iOS 11.0+
- tvOS 11.0+
Use this notification to customize your app's user interface (UI) for VoiceOver users. For example, if you display a UI element that briefly overlays other parts of your UI, you can make the display persistent for VoiceOver users, but allow it to disappear as designed for users who are not using VoiceOver. You can also use the
is function to determine whether VoiceOver is currently running.
Observe this notification using the default notification center. This notification does not include a parameter.