Contextual information about the state of the system that you use to create and update your UIKit view controller.
- iOS 13.0+
- Mac Catalyst 13.0+
- tvOS 13.0+
- Xcode 11.0+
UIView structure contains details about the current state of the system. When creating and updating your view controller, the system creates one of these structures and passes it to the appropriate method of your custom
UIView instance. Use the information in this structure to configure your view controller. For example, use the provided environment values to configure the appearance of your view controller and views. Don't create this structure yourself.