using System;

​

public interface IBase

{

    string Method();

}

​

public abstract class Base : IBase

{

    public string Method()

    {

        return "Sample";

    }

}

​

public class Implementation : Base // if I add ", IBase" to this it works as expected, but why?

{

    new public string Method()

    {

        return "Overriden";

    }

}

​

public class Program

{

    // and it's used like so...

    public static void Main()

    {

        IBase b = new Implementation();

        //Implementation b = new Implementation(); // It works as expected, always using Implementation.Method();

        Console.WriteLine(b.Method()); // Produces "Sample", so Base.Method(). Why not implementation?

        Console.WriteLine(((Implementation)b).Method()); // Produces "Overriden", so Implementation.Method(); Since when I have to downcast to use overriden method!?

    }

}