Instance Method

viewWillAppear(_:)

Notifies the view controller that its view is about to be added to a view hierarchy.

Declaration

func viewWillAppear(_ animated: Bool)

Parameters

animated

If true, the view is being added to the window using an animation.

Discussion

This method is called before the view controller'€™s view is about to be added to a view hierarchy and before any animations are configured for showing the view. You can override this method to perform custom tasks associated with displaying the view. For example, you might use this method to change the orientation or style of the status bar to coordinate with the orientation or style of the view being presented. If you override this method, you must call super at some point in your implementation.

For more information about the how views are added to view hierarchies by a view controller, and the sequence of messages that occur, see Supporting Accessibility.

See Also

Responding to View Events

func viewDidAppear(Bool)

Notifies the view controller that its view was added to a view hierarchy.

func viewWillDisappear(Bool)

Notifies the view controller that its view is about to be removed from a view hierarchy.

func viewDidDisappear(Bool)

Notifies the view controller that its view was removed from a view hierarchy.

var isBeingDismissed: Bool

A Boolean value indicating whether the view controller is being dismissed.

var isBeingPresented: Bool

A Boolean value indicating whether the view controller is being presented.

var isMovingFromParentViewController: Bool

A Boolean value indicating whether the view controller is being removed from a parent view controller.

var isMovingToParentViewController: Bool

A Boolean value indicating whether the view controller is being moved to a parent view controller.