享元模式
作者:互联网
概述
运用共享技术有效地支持大量细粒度的对象
结构图
代码实现
享元
/// <summary> /// 享元抽象 /// </summary> public abstract class Flyweight { public abstract void Operation(int extrinsicstate); }
/// <summary> /// 具体享元 /// </summary> public class ConcreteFlyweight : Flyweight { public override void Operation(int extrinsicstate) { Console.WriteLine("具体Flyweight:" + extrinsicstate); } }
/// <summary> /// 非享元 /// </summary> public class UnsharedConcreteFlyweight : Flyweight { public override void Operation(int extrinsicstate) { Console.WriteLine("不共享的具体Flyweight:" + extrinsicstate); } }
享元工厂
/// <summary> /// 享元工厂 /// </summary> public class FlyweightFactory { private Hashtable flyweights = new Hashtable(); public FlyweightFactory() { flyweights.Add("X", new ConcreteFlyweight()); flyweights.Add("Y", new ConcreteFlyweight()); flyweights.Add("Z", new ConcreteFlyweight()); } public Flyweight GetFlyweight(string key) { return ((Flyweight)flyweights[key]); } }
客户端
class Program { static void Main(string[] args) { int extrinsicstate = 22; FlyweightFactory f = new FlyweightFactory(); Flyweight fx = f.GetFlyweight("X"); fx.Operation(--extrinsicstate); Flyweight fy = f.GetFlyweight("Y"); fy.Operation(--extrinsicstate); Flyweight fz = f.GetFlyweight("Z"); fz.Operation(--extrinsicstate); UnsharedConcreteFlyweight uf = new UnsharedConcreteFlyweight(); uf.Operation(--extrinsicstate); Console.Read(); } }
运行结果
优势
相同对象只要保存一份,这降低了系统中对象的数量,从而降低了系统中细粒度对象给内存带来的压力。
使用场景
系统中有大量对象。
这些对象消耗大量内存。
这些对象的状态大部分可以外部化。
缺陷
为了使对象可以共享,需要将一些不能共享的状态外部化,这将增加程序的复杂性。
读取享元模式的外部状态会使得运行时间稍微变长。
标签:享元,extrinsicstate,模式,Flyweight,new,Operation,public 来源: https://www.cnblogs.com/netcjl/p/15421359.html