如何扩展类并重写来自接口的方法？

Question

I have the following scenario:

• interface IShape defines method Draw .
• class Circle implements IShape and the method Draw .
• class Rectangle implements IShape and the method Draw .
• class Square extends Rectangle and overrides the method Draw .

I wrote the code as following for the above scenario:

class Program
{
    static void Main(string[] args) { }
}

public interface IShape
{
    void Draw();
}

public class Circle : IShape
{
    public void Draw()
    {
        throw new NotImplementedException();
    }
}

public class Rectangle : IShape
{
    public void Draw()
    {
        throw new NotImplementedException();
    } 
}

public class Square : Rectangle
{
    public virtual void Draw()
    {
        throw new NotImplementedException();
    }
}

I am unable to get the last scenario which is class Square extends Rectangle and overrides the method Draw .

Any help?

Answer 1

Rectangle.Draw virtual, Square.Draw override

public class Rectangle : IShape
{
    public virtual void Draw()
    {
        throw new NotImplementedException();
    } 
}

public class Square : Rectangle
{
    public override void Draw()
    {
        throw new NotImplementedException();
    }
}