How Uno works on iOS
This article explores iOS-specific details of Uno's internals, with a focus on information that's useful for contributors to Uno. For an overview of how Uno works on all platforms, see this article.
UIElement inherits from UIView
UIElement in Uno is a native view on iOS, inheriting from the general UIView type. To elaborate, UIElement's base classes are the following:
UIKit.UIView → Uno.UI.Controls.BindableUIView → Windows.UI.Xaml.UIElement
Recall that UIElement implements DependencyObject as an interface in Uno.
Layouting
Uno's measure and arrange logic is triggered from the native iOS layout cycle. For a schematic of the control flow, see Layouting in iOS.