You need to go back the fundamentals of OOP and make sure you understand them and are comfortable to use them on practice, before returning to UI development or any other advanced issues. At the moment, you have no idea of how OOP works.
Every single member of the base class is inherited by the derived class. Nothing can prevent it,
ever; and nobody wants to prevent it, ever. The class can only be extended, but some methods can be
virtual and overridden, see the second link below.
It has
nothing to do with
NotInheritable
and
sealed
. These keywords prevent inheriting from the class as a while thing. Derived classes are not possible at all in this case.
http://en.wikipedia.org/wiki/Object-oriented_programming[
^],
http://en.wikipedia.org/wiki/Dynamic_dispatch[
^].
As to your problem, it simply does not exist. The only problem is that you want something you should not want. You did not provide any rational reasons.
—SA