public Memento(Book book)
{
ISBN = book.ISBN;
Title = book.Title;
Author = book.Author;
LastEdited = book.LastEdited;
}
public void TestMethod1()
{
Book book = new Book();
book.ISBN = "0450488357";
book.Title = "The Tommyknockers";
book.Author = "Stephen King";
book.ShowBook();
book.SaveUndo();
Thread.Sleep(1000);
// Modify book
book.ISBN = "0330376144";
book.Title = "The Rats";
book.Author = "James Herbert";
book.ShowBook();
book.SaveUndo();
book.PrintHistory();
book.RestoreToVersion(1);
book.ShowBook();
}
private static void RestoreBook(Book book, Memento memento)
{
if (memento != null && book != null)
{
book.RestoreFromUndo(memento);
}
}
public void SaveUndo(Book book)
{
_history.Add(book.CreateUndo());
}
public void RestoreToVersion(Book book, int versionNumber)
{
var memento = _history.FirstOrDefault(mem => mem.VersionNumber == versionNumber);
RestoreBook(book, memento);
}
public void RestoreToLatestVersion(Book book)
{
var memento = History.LastOrDefault();
RestoreBook(book, memento);
}