event--delegate(C#)

namespace EventDelegate
{
public delegate void SubEventHandler();
public abstract class Subject
{
public event SubEventHandler SubEvent;
protected void FireAway()
{
if (this.SubEvent != null)
{
this.SubEvent();
}
}
}

public class Cat : Subject
{
public void Cry()
{
Console.WriteLine("Cat cry!");
this.FireAway();
}
}

public abstract class Observer
{
public Observer(Subject sub)
{
sub.SubEvent +=new SubEventHandler(Response);
}

public abstract void Response();
}

public class Mouse : Observer
{
private string name;
public Mouse(string name, Subject sub)
: base(sub)
{
this.name = name;
}

public override void Response()
{
Console.WriteLine(name+" attempt to escape!");
}
}

public class Master : Observer
{
public Master(Subject sub)
: base(sub)
{ }

public override void Response()
{
Console.WriteLine("master waked up!");
}
}

class Program
{
static void Main(string[] args)
{
Cat cat = new Cat();
Mouse mouse1 = new Mouse("mouse1", cat);
Mouse mouse2 = new Mouse("mouse2", cat);
Master master = new Master(cat);
cat.Cry();
}
}
}