10. 程序设计: 猫大叫一声，所有的老鼠都开始逃跑，主人被惊醒。(C#语言) 要求： 1.要有联动性，老鼠和主人的行为是被动的。 2.考虑可扩展性，猫的叫声可能引起其他联动效应。 public interface Observer { void Response(); //观察者的响应，如是老鼠见到猫的反映 }
public interface Subject { void AimAt(Observer obs); //针对哪些观察者，这里指猫的要扑捉的对象---老鼠 }
public class Mouse : Observer {
private string name;
public Mouse(string name, Subject subj) { this.name = name; subj.AimAt(this); }
public void Response() { Console.WriteLine(name + attempt to escape!); }
}
public class Master : Observer {
public Master(Subject subj) { subj.AimAt(this); }
public void Response() { Console.WriteLine(Host waken!); }
}
public class Cat : Subject {
private ArrayList observers;
public Cat() { this.observers = new ArrayList(); }
public void AimAt(Observer obs) { this.observers.Add(obs); }
public void Cry() {
Console.WriteLine(Cat cryed!);
foreach (Observer obs in this.observers) { obs.Response(); }
}
}
class MainClass {
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();
}
}