DOTA版设计模式——享元

Dota中地图有那么多的树，为什么没有拖慢游戏速度那，在此就要讲讲享元模式了。
享元模式将类的粒度进一步细化，FlyWeight的意思是最轻量级选手，也称蝇量模式，对于大量数量的对象来说，类将内蕴状态和外蕴状态分开，内蕴只含最少的数据，剩下的交给外蕴。保证多对象内存消耗不会过大。
UML图：

测试代码：
DotaPatternLibrary.Flyweight.Trees trees = new DotaPatternLibrary.Flyweight.Trees();
            trees.Display();
            GetMemery();
            DotaPatternLibrary.Flyweight.NoFlyweightTrees noFlyweightTrees = new DotaPatternLibrary.Flyweight.NoFlyweightTrees();
            noFlyweightTrees.Display();
            GetMemery();
       public void GetMemery()
        {
            PerformanceCounter myMemory = new PerformanceCounter();
            myMemory.CategoryName = "Memory";
            myMemory.CounterName = "Available KBytes";

            string txtResult = "-->当前可用内存：" + myMemory.NextValue().ToString() + "KB";
            Graphics graphics = LandpyForm.Form.GetGraphics();
            graphics.DrawString(DateTime.Now.ToLongTimeString() + txtResult, new Font("宋体", 10f), new SolidBrush(Color.Red), 0, 0);
        }
完整代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Collections;

using DotaCommon;

namespace DotaPatternLibrary.Flyweight
{
    internal class Tree
    {
        private int _x;
        private int _y;
        private int _size;
        private Color _treeColor;

        public int X
        {
            get { return _x; }
            set { _x = value; }
        }

        public int Y
        {
            get { return _y; }
            set { _y = value; }
        }

        public int Size
        {
            get { return _size; }
            set { _size = value; }
        }

        public Color TreeColor
        {
            get { return _treeColor; }
            set { _treeColor = value; }
        }

        public Tree(int x, int y, int size, Color treeColor)
        {
            this._x = x;
            this._y = y;
            this._size = size;
            this._treeColor = treeColor;
        }

        public void Display()
        {
            Graphics graphic = LandpyForm.Form.GetGraphics();
            graphic.DrawEllipse(new Pen(new SolidBrush(this._treeColor)), _x, _y, _size, _size);
        }
    }

    public class NoFlyweightTrees
    {
        private Hashtable trees = new Hashtable();

        public NoFlyweightTrees()
        {
            for (int i = 0; i < 20000; i++)
            {
                Random random = new Random();
                int x = random.Next(0, LandpyForm.Form.PicWidth);
                int y = random.Next(0, LandpyForm.Form.PicHeight);
                int size = random.Next(3, 6);
                trees.Add("CasuarinaTree" + i, new Tree(x, y, size, Color.Brown));
                x = random.Next(0, LandpyForm.Form.PicWidth);
                y = random.Next(0, LandpyForm.Form.PicHeight);
                size = random.Next(3, 6);
                trees.Add("YoungTree" + i, new Tree(x, y, size, Color.Green));
            }
        }
        public void Display()
        {
            for (int i = 0; i < 20000; i++)
            {
                Tree tree = trees["CasuarinaTree" + i] as Tree;
                tree.Display();
                tree = trees["YoungTree" + i] as Tree;
                tree.Display();
            }
            Graphics graphic = LandpyForm.Form.GetGraphics();
            graphic.DrawString("OK", new Font("宋体", 12f), new SolidBrush(Color.Black), 0, 0);
        }
    }

    public class Trees
    {
        private Hashtable trees = new Hashtable();

        public Trees()
        {
            for (int i = 0; i < 20000; i++)
            {
                trees.Add("CasuarinaTree" + i, new CasuarinaTree());
                trees.Add("YoungTree" + i, new YoungTree());
            }
        }
        public void Display()
        {
            for (int i = 0; i < 20000; i++)
            {
                Random random = new Random();
                int x = random.Next(0, LandpyForm.Form.PicWidth);
                int y = random.Next(0, LandpyForm.Form.PicHeight);
                int size = random.Next(3, 6);
                IFlyweightTree tree = trees["CasuarinaTree" + i] as IFlyweightTree;
                tree.Display(x, y, size);
                x = random.Next(0, LandpyForm.Form.PicWidth);
                y = random.Next(0, LandpyForm.Form.PicHeight);
                size = random.Next(3, 6);
                tree = trees["YoungTree" + i] as IFlyweightTree;
                tree.Display(x, y, size);
            }
            Graphics graphic = LandpyForm.Form.GetGraphics();
            graphic.DrawString("OK", new Font("宋体", 12f), new SolidBrush(Color.Black), 0, 0);
        }
    }

    internal interface IFlyweightTree
    {
        void Display(int _x, int _y, int _size);
    }

    internal class CasuarinaTree : IFlyweightTree
    {
        public void Display(int _x, int _y, int _size)
        {
            Graphics graphic = LandpyForm.Form.GetGraphics();
            graphic.DrawEllipse(new Pen(new SolidBrush(Color.Brown)), _x, _y, _size, _size);
        }
    }

    internal class YoungTree : IFlyweightTree
    {
        #region IFlyweightTree 成员

        public void Display(int _x, int _y, int _size)
        {
            Graphics graphic = LandpyForm.Form.GetGraphics();
            graphic.DrawEllipse(new Pen(new SolidBrush(Color.Green)), _x, _y, _size, _size);
        }

        #endregion
    }
}