Public Overrides Sub AddValueChanged ( _
    component As Object, _
    handler As EventHandler _
)

Dim instance As DependencyPropertyDescriptor
Dim component As Object
Dim handler As EventHandler

instance.AddValueChanged(component, handler)

public override void AddValueChanged(
    Object component,
    EventHandler handler
)

public:
virtual void AddValueChanged(
    Object^ component, 
    EventHandler^ handler
) override

public override function AddValueChanged(
    component : Object, 
    handler : EventHandler
)

You cannot use methods in XAML.