namespace EventsPractice
{
    class Program
    {
        static void Main(string[] args)
        {
            Point point = new Point();

            point.PointChanged += HandlePointChanged;
        }

    }
    class Point
    {
        private double x;
        private double y;

        public double X
        {
            get { return x; }
            set
            {
                x = value;
                OnPointChanged();
            }
        }
        public double Y
        {
            get { return y; }
            set
            {
                y = value;
                OnPointChanged();
            }

        }

        public event EventHandler PointChanged;

        public void OnPointChanged()
        {
            if (PointChanged != null)
                PointChanged(this, EventArgs.Empty);
        }

        public void HandlePointChanged(object sender, EventArgs eventArgs)
        {
            // Do something Here
        }

    }
}

point.PointChanged += HandlePointChanged;