using System;

public class Program

{

    public static void Main()

    {

        A classA = new A();

        B classB = new B();

        classA.myMethod();

        classB.myMethod();

        classA.ifMethod(1, "hello");

        classB.ifMethod(2, "goodbye");

    }

​

}

​

public interface IA

{

    void ifMethod(int i, string j);

}

​

public class A : IA

{

    public A() {

        Console.WriteLine("A constructor");

    }

    public virtual void myMethod(){

        Console.WriteLine("A method");

    }

    public void ifMethod(int i, string j) {

        Console.WriteLine("if method A");

    }       

}

​

public class B : A

{

    public B() {

        Console.WriteLine("B constructor");

    }

    public override void myMethod(){

        base.myMethod();

        Console.WriteLine("B method");

    }   

    public new void ifMethod(int i, string j) {

        base.ifMethod(i, j);

    }

}