using System;

​

public class HeaderBase

{

    public int HeaderSize { get { return sizeof(byte); } }

    public byte[] Content {get; private set;}

    public HeaderBase(byte[] bytes)

    {

        Content = bytes;

    }

}

​

public class BiggerHeader : HeaderBase

{

    public BiggerHeader(HeaderBase header) : base(header.Content)

    {

    }

    public new int HeaderSize { get { return sizeof(byte) + sizeof(UInt32); } }

}

​

public class Program

{

    public static void Main()

    {

        byte[] bytes = new byte[]{0xFF};

        HeaderBase b = new HeaderBase(bytes);

        BiggerHeader d = new BiggerHeader(b);

        BiggerHeader d2 = Get<BiggerHeader>();

        Console.WriteLine(b.HeaderSize);

        Console.WriteLine(d.HeaderSize);

        Console.WriteLine(d2.HeaderSize);

    }

    public static T Get<T>() where T : HeaderBase

    {

        HeaderBase b = new HeaderBase(new byte[]{});

        T instance = (T)Activator.CreateInstance(typeof(T), b);

        Console.WriteLine(instance.HeaderSize);

        return instance;

    }

}