Memento Design Patterns - Behavioral Patterns in C#

Memento: Allows you to save the state of an object externally from that object.

* Without violating encapsulation, capture and externalize an object's internal state so that the 

object can be restored to this state later.


 class Program
    {
        static void Main(string[] args)
        {
            Originator org = new Originator();
            org.State = "ON";

            //Store internal state
            Caretaker c = new Caretaker();
            c.Memento = org.CreateMemento();

            //Continue changing originator
            org.State = "OFF";

            //Restore saved state
            org.SetMemento(c.Memento);

            Console.ReadKey();
        }
    }
    class Originator
    {
        private string _state;

        public string State
        {
            get { return _state; }
            set
            {
                _state = value;
                Console.WriteLine("State = " + _state);
            }
        }
        //Creates memento
        public Memento CreateMemento()
        {
            return (new Memento(_state));
        }
        public void SetMemento(Memento memento)
        {
            Console.WriteLine("Restoring state..");
            State = memento.State;
        }
    }
    class Memento
    {
        private string _state;
        public Memento(string state)
        {
            this._state = state;
        }
        public string State
        {
            get { return _state; }
        }
    }
    class Caretaker
    {
        private Memento _memento;
        public Memento Memento
        {
            set { _memento = value; }
            get { return _memento; }
        }

    }