Posted by UIKit when VoiceOver starts or stops. This notification does not include a parameter.
- iOS 4.0–11.0Deprecated
- tvOS 9.0–11.0Deprecated
Use this notification to customize your application’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
UIAccessibility function to determine whether VoiceOver is currently running.
Observe this notification using the default notification center.