分析详见：http://lvxingzhelimin.blog.163.com/blog/static/1707165502011101655652697/
@H_502_4@using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { //老板胡汉三 Boss huhansan = new Boss() ; //看股票的同事 StockObserver tongshi1 = new StockObserver("魏关拆",huhansan); NBAObserver tongshi2 = new NBAObserver("易观查",huhansan); huhansan.Attach(tongshi1 ); huhansan.Attach(tongshi2); huhansan.Detach(tongshi1); //老板回来 huhansan.SubjectState = "我胡汉三又回来了！"; //发出通知 huhansan.Notify(); Console.Read(); } } } //通知者接口 interface Subject { void Attach(Observer observer); void Detach(Observer observer); void Notify(); string SubjectState { get; set; } } //老板类 class Boss :Subject { //同事列表 private IList< Observer > observers = new List < Observer >(); private string action; //增加 public void Attach(Observer observer) { observers.Add(observer ); } //减少 public void Detach(Observer observer) { observers.Remove(observer ); } //通知 public void Notify() { foreach (Observer o in observers) o.Update(); } //老板类的状态 public string SubjectState { get { return action; } set { action = value; } } } //抽象观察者 abstract class Observer { protected string name; protected Subject sub; //构造方法,指明观察者姓名建立和通知者间的关联 public Observer(string name,Subject sub) { this.name = name; this.sub = sub; } //定义抽象方法——更新 public abstract void Update(); } //看股票的同事 class StockObserver : Observer { //首先建立与继承的父类的最基本的属性设置 public StockObserver(string name,Subject sub ):base (name,sub ) { } //看股票同事的更新事件，重写父类的Update方法。 public override void Update() { Console.WriteLine("{0} {1} 关闭股票行情，继续工作！",sub .SubjectState,name); } } //看NBA的同事 class NBAObserver : Observer { //添加一个构造方法，指定看NBA同事这个类的姓名和与之关联的观察者 public NBAObserver(string name,Subject sub) : base(name,sub) { } //重写更新方法 public override void Update() { Console.WriteLine("{0}{1}关闭NBA，继续工作！",name ); } }
