230

Структура паттерна на языке C#

Модель вытягивания (Pull model)

class Program { static void Main() { ConcreteSubject subject = new ConcreteSubject(); subject.Attach(new ConcreteObserver(subject)); subject.Attach(new ConcreteObserver(subject)); subject.State = "Some State ..."; subject.Notify(); } }

	abstract class Subject
	{
	ArrayList observers = new ArrayList();
	public void Attach(Observer observer)
	{
	observers.Add(observer);
	}
			abstract class Observer
	public void Detach(Observer observer)		{
	{		public abstract void Update();
	observers.Remove(observer);		}
	}
	public void Notify()
	{
	foreach (Observer observer in observers)
	observer.Update();		class ConcreteObserver : Observer
	}		{
	}		string observerState;
			ConcreteSubject subject;
			public ConcreteObserver(ConcreteSubject subject)
			{
			this.subject = subject;
	class ConcreteSubject : Subject		}
	{		public override void Update()
	public string State { get; set;	}
			{
	}
			observerState = subject.State;
			}
			}

См. Пример к главе: \019_Observer\001_Observer [project ObserverPull]

231

Модель проталкивания (Push model)

		class Program
		{
		static void Main()
		{
		ConcreteSubject subject = new ConcreteSubject();
		subject.Attach(new ConcreteObserver(subject));
		subject.Attach(new ConcreteObserver(subject));
		subject.State		= "Some State ...";
		subject.Notify();
		}
		}
	abstract class Subject
	{
	ArrayList observers = new ArrayList();
	public void Attach(Observer observer)
	{
	observers.Add(observer);
	}
	public void Detach(Observer observer)
	{			abstract class Observer
	observers.Remove(observer);			{
	}			public abstract void Update(string state);
				}
	public override string State	{ get; set;	}
	public void Notify()
	{
	foreach (Observer observer in observers)			class ConcreteObserver : Observer
	observer.Update(State);
				{
	}
				string observerState;
	}
				ConcreteSubject subject;
				public ConcreteObserver(ConcreteSubject subject)
				{
				this.subject = subject;
	class ConcreteSubject : Subject			}
	{			public override void Update(string state)
	public override string State	{ get; set;	}
				{
	}
				observerState = state;
				}
				}

См. Пример к главе: \019_Observer\001_Observer [project ObserverPush]