UIView View Will Appear(Boolean) Controller.
View Will Appear(Boolean)
Called prior to the View being added to the view hierarchy.
[Foundation.Export("viewWillAppear:")] public virtual void ViewWillAppear (bool animated);
abstract member ViewWillAppear : bool -> unit override this.ViewWillAppear : bool -> unit
Application developers who override this method must call
base.ViewWillAppear() in their overridden method.