public static void ShowDemo() { Console.WriteLine("春游活动的 观察者模式 演示"); //春游活动组织发起者 HappyBar bar = new HappyBar(); IObserver memberZhang = new QQMember() { Name = "张智", happyBar = bar }; IObserver memberDing = new QQMember() { Name = "丁朝阳", happyBar = bar }; IObserver memberZheng = new QQMember() { Name = "郑亚敏", happyBar = bar }; bar.Attach(memberZhang); //张智参加活动 bar.Attach(memberDing); //丁朝阳参加活动 bar.Attach(memberZheng); //郑亚敏参加互动 bar.Detach(memberZhang); //张智临时有事,取消活动 //设置活动信息 bar.PublishInfo = " 怀柔水长城 时间:2012年4月XX日"; //发起活动及通知 bar.Notify(); }