static void Main(string[] args)
{
Secretary tongzijie = new Secretary();
StockObserver tongshi1 = new StockObserver("张三", tongzijie);
StockObserver tongshi2 = new StockObserver("李四", tongzijie);
tongzijie.Attach(tongshi1);
tongzijie.Attach(tongshi2);
tongzijie.SecretaryAction = "老板回来了！";
tongzijie.Notify();
Console.ReadLine();
}
/// <summary>
/// 增加
/// </summary>
/// <param name="observer"></param>
public void Attach(StockObserver observer)
{
observers.Add(observer);
}