Initializes a new instance of a class derived from MarkupExtension.
protected MarkupExtension ();
Protected Sub New ()
The MarkupExtension abstract class does not hold any private values that require initialization.
Notes to Inheritors
A functional markup extension should define its own public parameterless constructor. Additionally, the markup extension should implement constructors that are appropriate for the extension's intended capabilities and markup usage. For more information, see Markup Extensions for XAML Overview.