Listing 12-6 extracted from chapter Inheritance, polymorphism and abstraction

Listing 12-5<     > Listing 12-7

This listing can be compiled with the command line:
csc.exe /target:library Example_12_6.cs
Errors: 0 Warnings: 0

class A { public virtual void Foo() { /*...*/ } }
abstract class B : A { public abstract override void Foo();}
// The C class MUST override the Foo() method.
class C : B { public override void Foo() { /*...*/ } }