Gets the final render size of a UIElement.
Assembly: System.Windows (in System.Windows.dll)
is generally not the property to use to obtain size information about a UI element. For general UI purposes, use ActualHeight or ActualWidth instead, and do so only at points in object lifetime where object layout is complete. For layout method override purposes, use DesiredSize.
In WPF, this property is useful as a connection point for processing a UIElement with a lower-level graphics implementation based on Visual. Silverlight does not expose a similar lower-level graphics API or Visual class, so the scenarios for using this property are limited.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.