public static void ShowDemo() { Console.WriteLine("春游活动的 观察者模式 演示 (使用 C# 的 delegate 机制) "); HappyBar hb = new HappyBar(); QQMember member1 = new QQMember() { Name = "张三", happyBar = hb }; QQMember member2 = new QQMember() { Name = "李四", happyBar = hb }; hb.PublishInfo = " 怀柔水长城 时间:2012年4月XX日"; hb.GoUpdate += new HappyBar.EventHandler(member1.GoToUpdate); hb.GoUpdate += new HappyBar.EventHandler(member2.GoToUpdate); hb.Notify(); }