Design Patterns 26 - 享元模式

abstract class Flyweight {
    public abstract void Operation(int extrinsicstate);
}

class ConcreteFlyweight : Flyweight {
    public override void Operation(int extrinsicstate) {
        // todo
    }
}

class UnsharedConcreteFlyweight : Flyweight {
    public override void Operation(int extrinsicstate) {
        // todo
    }
}

class FlyweightFactory {
    private Hashtable flyweights = new Hashtable();

    public FlyweightFactory() {
        flyweights.Add("X", new ConcreteFlyweight());
        flyweights.Add("Y", new ConcreteFlyweight());
        flyweights.Add("Z", new ConcreteFlyweight());
    }

    publiuc Flyweight GetFlyweight(string key) {
        return ((Flyweight)flyweights[key]);
    }
}