Desktop
WPF
If you are familiar with WPF you are aware that the the grand daddy of all controls is FrameworkElement. It is defined in the PresentationFramework.dll assembly and derives from UIElement (defined in PresentationCore.dll). Its purpose is to serve as a base element for all framework related stuff: styles, inheritance context, etc. However there is another framework element - FrameworkContentElement. The main distinct between them is that the later did not defines its own rendering behavior (its inheritors should do so). This is way properties like: (Actual)Width or (Actual)Height are not present at FrameworkContentElement. If you examine the classes that derive from FrameworkContentElement...