public void NotifyPropertyChanged(
	string propertyName = null
)

Public Sub NotifyPropertyChanged ( 
	Optional propertyName As String = Nothing
)

public:
void NotifyPropertyChanged(
	String^ propertyName = nullptr
)

member NotifyPropertyChanged : 
        ?propertyName : string 
(* Defaults:
        let _propertyName = defaultArg propertyName null
*)
-> unit