Memento Pattern

Memento pattern allows you to capture the internal state of the object without violating encapsulation and later on you can undo/ revert the changes when required.

http://1.bp.blogspot.com/_DSP5FXX4Isw/S_RTzRBYTgI/AAAAAAAAC9g/-3sgBf8lU44/s320/memento.JPG

public class  OriginalObject
    {
        public string  String1 { get; set; }
        public string  String2 { get; set; }
        public Memento MyMemento { get; set; }
 
        public OriginalObject(string str1, string str2)
        {
            this.String1 = str1;
            this.String2 = str2;
            this.MyMemento = new  Memento(str1, str2);
        }
        public void  Revert()
        {
            this.String1 = this.MyMemento.String1;
            this.String2 = this.MyMemento.String2;
        }
    }
 
    public class  Memento
    {
        public string  String1 { get; set; }
        public string  String2 { get; set; }
 
        public Memento(string str1, string str2)
        {
            this.String1 = str1;
            this.String2 = str2;
        }
    }

Here you can see the Memento object is actually used to revert the changes made in the object.