C#

// The interface shown in the docs
    public interface IDrawingObject
    {
        // Raise this event before drawing
        // the object.
        event EventHandler OnDraw;
    }

// The implementer class shown in the docs
    public class Shape : IDrawingObject, IShape
    {
        // Create an event for each interface event
        event EventHandler PreDrawEvent;
        event EventHandler PostDrawEvent;

        // I left out some stuff here
    }

// The subscriber class
    public class Subscriber1
    {
        // References the shape object as an IDrawingObject
        public Subscriber1(Shape shape)
        {
            IDrawingObject d = (IDrawingObject)shape;
            d.OnDraw += new EventHandler(d_OnDraw);
        }

        void d_OnDraw(object sender, EventArgs e)
        {
            Console.WriteLine("Sub1 receives the IDrawingObject event.");
        }
    }