static void Main(string[] args) { MenuForm mn = new MenuForm(); mn.addMenuItem("1. Add a book"); mn.addMenuItem("2. Find a book"); mn.addMenuItem("3. Show book list"); mn.addMenuItem("4. Remove a book"); mn.addMenuItem("5. Exit"); int choice = 0; BookLibrary bookLibrary = new BookLibrary(); do { Console.WriteLine("********** Book Management **********"); choice = mn.GetChoice(0, 5); switch (choice) { case 1: string id = Util.getString("Input ID: ", "ID is invalid"); string name = Util.getString("Input Book Name: ", "Book name is invalid"); string author = Util.getString("Input Author: ", "Author is invalid"); string publisher = Util.getString("Input Publisher: ", "Publisher is invalid"); Book book = new Book(id, name, author, publisher); bookLibrary.AddBook(book); Console.WriteLine("Added new book!"); break; case 2: string searchedID = Util.getString("Input ID to find book: ", "ID is invalid"); Book foundBook = bookLibrary.FindBook(searchedID); if (foundBook != null) { Console.WriteLine(foundBook.ToString()); } else { Console.WriteLine("Book not found!"); } break; case 3: bookLibrary.ShowBookList(); break; case 4: string removedID = Util.getString("Input ID to remove book: ", "ID is invalid"); bool removed = bookLibrary.RemoveBook(removedID); if (removed) { Console.WriteLine("Removed " + removedID + " book successfully"); } else { Console.WriteLine("Removed " + removedID + " book failed"); } break; } } while (choice > 0 && choice < 5); }