static void Main(string[] args)
{
// Initialize the receiver - in our case; the display
Display display = new Display(10); // 10
// Initialize the invoker - in our case; the equals button
EqualsButton equalsButton = new EqualsButton();
// Add some commands to the invoker's queue
equalsButton.pushCommand(new AddCommand(10, display)); // 20
equalsButton.pushCommand(new SubtractCommand(1, display)); // 19
equalsButton.pushCommand(new AddCommand(20, display)); // 39
equalsButton.pushCommand(new SubtractCommand(13, display)); // 26
equalsButton.pushCommand(new AddCommand(27, display)); // 53
equalsButton.pushCommand(new SubtractCommand(49, display)); // 4
equalsButton.pushCommand(new AddCommand(201, display)); // 205
// Let the invoker do its job - Now displaying: 205
equalsButton.invoke();
// Lets undo the last three commands - Now displaying: 26
equalsButton.undo(3);
Console.ReadLine();
}
// Constructor
public SubtractCommand(int value, Display display)
{
this._display = display;
this._value = value;
}
// Constructor
public AddCommand(int value, Display display)
{
this._display = display;
this._value = value;
}
