//主题类class ConcreteSubject{private IList<ConcreteObserver> lstConcreteObserver = new List<ConcreteObserver>();private string action;//添加观察者public void Add(ConcreteObserver concreteObserver){lstConcreteObserver.Add(concreteObserver);}//移除观察者public void Remove(ConcreteObserver concreteObserver){lstConcreteObserver.Remove(concreteObserver);}//通知观察者类public void Notify(){foreach (ConcreteObserver observer in lstConcreteObserver){observer.Update();}}//定义主题发现的某一状态public string ConcreteAction{get { return action; }set { action = value; }}}//观察者类class ConcreteObserver{protected ConcreteSubject subject;protected string name;public ConcreteObserver(ConcreteSubject subject, string name){this.subject = subject;this.name = name;}//观察者更新行为public void Update(){Console.WriteLine($"{subject.ConcreteAction},{name}，别睡觉了，快醒醒！");}}static void Main(string[] args){ConcreteSubject subject = new ConcreteSubject();ConcreteObserver observer = new ConcreteObserver(subject, "michael");subject.Add(observer);subject.ConcreteAction = "老师来了";subject.Notify();Console.Read();}

     //抽象观察者类abstract class Observer{public abstract void Update();}//抽象主题类abstract class Subject{private IList<Observer> lstConcreteObserver = new List<Observer>();public void Add(Observer concreteObserver){lstConcreteObserver.Add(concreteObserver);}public void Remove(Observer concreteObserver){lstConcreteObserver.Remove(concreteObserver);}public void Notify(){foreach (Observer observer in lstConcreteObserver){observer.Update();}}}//具体观察者类class ConcreteObserver:Observer{protected ConcreteSubject subject;protected string name;private string observerState;public ConcreteObserver(ConcreteSubject subject, string name){this.subject = subject;this.name = name;}public override void Update(){this.observerState = subject.ConcreteAction;Console.WriteLine($"the observer's of {name} state is {observerState}");}}//具体主题对象class ConcreteSubject:Subject{      private string action;      public string ConcreteAction{get { return action; }set { action = value; }}}static void Main(string[] args){ConcreteSubject subject = new ConcreteSubject();subject.Add(new ConcreteObserver(subject, "michael"));subject.Add(new ConcreteObserver(subject, "jarle"));subject.Add(new ConcreteObserver(subject, "cumming"));subject.ConcreteAction = "Ready";subject.Notify();Console.Read();}

    class Mao{private string name;public delegate void MaoDelegateHandler();public event MaoDelegateHandler MaoEventHandler;public Mao(string name){this.name = name;}public void Miao(){Console.WriteLine($"{this.name}叫了一声");Notify();}public void Notify(){if (MaoEventHandler != null)MaoEventHandler();}public string Name{get { return name; }set { name = value; }}}class Laoshu{public void Run(){Console.WriteLine("老鼠逃跑了");}}class People{public void Wake(){Console.WriteLine("主人被惊醒了");}}class Program{static void Main(string[] args){Mao mao = new Mao("大脸猫");Laoshu laoshu = new Laoshu();People people = new People();//注册事件 这两种方式都可以mao.MaoEventHandler += new Mao.MaoDelegateHandler(laoshu.Run);mao.MaoEventHandler += people.Wake;//猫叫了一声 会自动调用注册过的方法
            mao.Miao();Console.Read();}}

    class Mao{private string name;//声明委托public delegate void MaoDelegateHandler(object sender, MaoEventArgs e);//声明事件public event MaoDelegateHandler MaoEventHandler;public class MaoEventArgs : EventArgs{private string name;public MaoEventArgs(string name){this.name = name;}}public Mao(string name){this.name = name;}//发布者 某一行为后 发出通知public void Miao(){Console.WriteLine($"{this.name}叫了一声");//建立MaoEventArgs对象MaoEventArgs e = new MaoEventArgs(this.Name);//调用通知方法
            Notify(e);}public void Notify(MaoEventArgs e){//如果有订阅者注册if (MaoEventHandler != null)//执行所有注册的方法MaoEventHandler(this,e);}public string Name{get { return name; }set { name = value; }}}class Laoshu{//是不是很熟悉,请自行脑补winfom中grid的事件及sender和e是什么public void Run(object sender,Mao.MaoEventArgs e){Mao mao = (sender as Mao);Console.WriteLine($"{mao.Name}来了，老鼠逃跑了");}}class People{public void Wake(object sender, Mao.MaoEventArgs e){Mao mao = (sender as Mao);Console.WriteLine($"{mao.Name}的主人被惊醒了");}}class Program{static void Main(string[] args){Mao mao = new Mao("大脸猫");Laoshu laoshu = new Laoshu();People people = new People();//注册事件 这两种方式都可以mao.MaoEventHandler += new Mao.MaoDelegateHandler(laoshu.Run);mao.MaoEventHandler += people.Wake;//猫叫了一声 会自动调用注册过的方法
            mao.Miao();Console.Read();}}