Difference between new and override?

Question

I have a base class which I want to provide some \'base\' functionality for methods for all inheriting classes.

In my inheriting classes I want to do:

Answer 1

It says so because you have not declared the base method virtual. Once you do so, the base virtual/derived override pair of keywords will make sense. Right now, the compiler is complaining that you cannot override a non-virtual method.