Demonstrate the difference between method hiding and overriding.

override.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace MethodHiding
{
    class Program
    {

        class A
        {
            public void Foo()
            {
                System.Console.WriteLine("A::Foo");
            }

            public virtual void Bar()
            {
                System.Console.WriteLine("A::Bar");
            }
        }

        class B : A
        {
            public new void Foo()
            {
                System.Console.WriteLine("B::Foo");
            }

            public override void Bar()
            {
                System.Console.WriteLine("B::Bar");
            }
        }
        static void Main(string[] args)
        {
            A a = new A();
            a.Foo();
            a.Bar();

            B b = new B();
            b.Foo();
            b.Bar();

            A ab = new B();
            ab.Foo();
            ab.Bar();

            System.Console.ReadLine();
        }
    }
}

The output of the above is:
A::Foo
A::Bar
B::Foo
B::Bar
A::Foo
B::Bar