AbstractFactory抽象工厂(创建型模式)

动机：
　　在软件系统中，经常面临着“一系列相互依赖的对象”的创建工作；同时，由于需求的变化，往往存在更多系列对象的创建工作。
　　如何应对这种变化？如何绕过常规的对象创建方法(new)，提供一种“封装机制”来避免客房程序和这种“多系列具体对象创建工作”的支耦合？

意图：
　　提供一个接口，让该接口负责创建一系列“相关或者相互依赖的对象”，无需指定它们具体的类。
　　出自：《设计模式》GoF

Abstract Factory模式的几个要点：
　　１、如果没有应对“多系列对象构建”的需求变化，则没有必要使用Abstract Factroy模式，这里使用简单的静态工厂完全可以。
　　２、“系列对象”指的是这些对象之间有相互依赖、或作用的关系，例如游戏开发场景中的“道路”与“房屋”的依赖，“道路”与“地道”的依赖。
　　３、Abstract Factory模式主要在于应对“新系列”的需求变动。其缺点在于难以应用“新对象”的需求变动。
　　４、Abstract Factory模式经常和Factory Method模式共同组合来应对“对象创建”的需求变化。

稳定部分

 1using System;
 2using System.Drawing ;
 3namespace Gardener
 4{
 5    /**//// <summary>
 6    /// Summary description for Garden.
 7    /// </summary>
 8    public class Garden {
 9        protected Plant center, shade, border;
10        protected bool showCenter, showShade, showBorder;
11        //select which ones to display
12        public void setCenter() {showCenter = true;}
13        public void setBorder() {showBorder =true;}
14        public void setShade() {showShade =true;}
15        //draw each plant
16        public void draw(Graphics g) {
17            if (showCenter) center.draw (g, 100, 100);
18            if (showShade) shade.draw (g, 10, 50);
19            if (showBorder) border.draw (g, 50, 150);
20        }
21    }
22}
23

变化部分:

 1using System;
 2using System.Drawing ;
 3
 4namespace Gardener
 5{
 6    /**//// <summary>
 7    /// Summary description for AnnualGarden.
 8    /// </summary>
 9    public class AnnualGarden : Garden
10    {
11        public AnnualGarden () {
12            shade = new Plant("Coleus");
13            border = new Plant ("Alyssum");
14            center = new Plant ("Marigold");
15        }
16    }
17public class PerennialGarden : Garden
18    {
19        public PerennialGarden() {
20            shade = new Plant("Astilbe");
21            border = new Plant ("Dicentrum");
22            center = new Plant ("Sedum");
23        }
24    }
25public class VeggieGarden : Garden     {
26        public VeggieGarden() {
27            shade = new Plant("Broccoli");
28            border = new Plant ("Peas");
29            center = new Plant ("Corn");
30        }
31    }
32}
33

工厂:

 1using System;
 2using System.Collections;
 3using System.ComponentModel;
 4using System.Drawing;
 5using System.Data;
 6using System.Windows.Forms;
 7
 8namespace Gardener
 9{
10    /**//// <summary>
11    /// Summary description for GdPic.
12    /// </summary>
13    public class GdPic : System.Windows.Forms.PictureBox 
14    {
15        /**//// <summary> 
16        /// Required designer variable.
17        /// </summary>
18        private System.ComponentModel.Container components = null;
19        private Brush br;
20        private Garden gden;
21        private void init () {
22            br = new SolidBrush (Color.LightGray );
23        }
24        public GdPic()     {
25            // This call is required by the Windows.Forms Form Designer.
26            InitializeComponent();
27            init();
28        }
29        public void setGarden(Garden garden) {
30            gden = garden;
31        }
32        protected override void OnPaint ( PaintEventArgs pe ){
33            Graphics g = pe.Graphics;
34            g.FillEllipse (br, 5, 5, 100, 100);
35            if(gden != null)
36                gden.draw (g);    
37        }
38
39        /**//// <summary> 
40        /// Clean up any resources being used.
41        /// </summary>
42        protected override void Dispose( bool disposing )
43        {
44            if( disposing )
45            {
46                if(components != null)
47                {
48                    components.Dispose();
49                }
50            }
51            base.Dispose( disposing );
52        }
53
54        Component Designer generated code#region Component Designer generated code
55        /**//// <summary> 
56        /// Required method for Designer support - do not modify 
57        /// the contents of this method with the code editor.
58        /// </summary>
59        private void InitializeComponent()
60        {
61            // 
62            // GdPic
63            // 
64            
65        }
66        #endregion
67
68    }
69}
70

主程序:

  1using System;
  2using System.Drawing;
  3using System.Collections;
  4using System.ComponentModel;
  5using System.Windows.Forms;
  6using System.Data;
  7
  8namespace Gardener
  9{
 10    /**//// <summary>
 11    /// Summary description for Form1.
 12    /// </summary>
 13    public class Form1 : System.Windows.Forms.Form
 14    {
 15        private System.Windows.Forms.GroupBox groupBox1;
 16        private Gardener.GdPic gdPic1;
 17        private System.Windows.Forms.RadioButton opAnnual;
 18        private System.Windows.Forms.RadioButton opVegetable;
 19        private System.Windows.Forms.RadioButton opPerennial;
 20        private System.Windows.Forms.CheckBox ckCenter;
 21        private System.Windows.Forms.CheckBox ckBorder;
 22        private System.Windows.Forms.CheckBox ckShade;
 23        /**//// <summary>
 24        /// Required designer variable.
 25        /// </summary>
 26        private System.ComponentModel.Container components = null;
 27        private Garden garden;
 28        private void init() {
 29        }
 30        public Form1()
 31        {
 32            //
 33            // Required for Windows Form Designer support
 34            //
 35            InitializeComponent();
 36            init();
 37            //
 38            // TODO: Add any constructor code after InitializeComponent call
 39            //
 40        }
 41
 42        /**//// <summary>
 43        /// Clean up any resources being used.
 44        /// </summary>
 45        protected override void Dispose( bool disposing )
 46        {
 47            if( disposing )
 48            {
 49                if (components != null) 
 50                {
 51                    components.Dispose();
 52                }
 53            }
 54            base.Dispose( disposing );
 55        }
 56
 57        Windows Form Designer generated code#region Windows Form Designer generated code
 58        /**//// <summary>
 59        /// Required method for Designer support - do not modify
 60        /// the contents of this method with the code editor.
 61        /// </summary>
 62        private void InitializeComponent()
 63        {
 64            this.ckCenter = new System.Windows.Forms.CheckBox();
 65            this.gdPic1 = new Gardener.GdPic();
 66            this.opVegetable = new System.Windows.Forms.RadioButton();
 67            this.ckBorder = new System.Windows.Forms.CheckBox();
 68            this.ckShade = new System.Windows.Forms.CheckBox();
 69            this.groupBox1 = new System.Windows.Forms.GroupBox();
 70            this.opPerennial = new System.Windows.Forms.RadioButton();
 71            this.opAnnual = new System.Windows.Forms.RadioButton();
 72            this.groupBox1.SuspendLayout();
 73            this.SuspendLayout();
 74            // 
 75            // ckCenter
 76            // 
 77            this.ckCenter.Location = new System.Drawing.Point(160, 208);
 78            this.ckCenter.Name = "ckCenter";
 79            this.ckCenter.Size = new System.Drawing.Size(64, 16);
 80            this.ckCenter.TabIndex = 2;
 81            this.ckCenter.Text = "Center";
 82            this.ckCenter.CheckedChanged += new System.EventHandler(this.ckCenter_CheckedChanged);
 83            // 
 84            // gdPic1
 85            // 
 86            this.gdPic1.BackColor = System.Drawing.SystemColors.ActiveCaptionText;
 87            this.gdPic1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
 88            this.gdPic1.Location = new System.Drawing.Point(160, 8);
 89            this.gdPic1.Name = "gdPic1";
 90            this.gdPic1.Size = new System.Drawing.Size(184, 192);
 91            this.gdPic1.TabIndex = 1;
 92            this.gdPic1.TabStop = false;
 93            // 
 94            // opVegetable
 95            // 
 96            this.opVegetable.Location = new System.Drawing.Point(16, 48);
 97            this.opVegetable.Name = "opVegetable";
 98            this.opVegetable.Size = new System.Drawing.Size(80, 16);
 99            this.opVegetable.TabIndex = 1;
100            this.opVegetable.Text = "Vegetable";
101            this.opVegetable.CheckedChanged += new System.EventHandler(this.opVegetable_CheckedChanged);
102            // 
103            // ckBorder
104            // 
105            this.ckBorder.Location = new System.Drawing.Point(224, 208);
106            this.ckBorder.Name = "ckBorder";
107            this.ckBorder.Size = new System.Drawing.Size(64, 16);
108            this.ckBorder.TabIndex = 3;
109            this.ckBorder.Text = "Border";
110            this.ckBorder.CheckedChanged += new System.EventHandler(this.ckBorder_CheckedChanged);
111            // 
112            // ckShade
113            // 
114            this.ckShade.Location = new System.Drawing.Point(288, 208);
115            this.ckShade.Name = "ckShade";
116            this.ckShade.Size = new System.Drawing.Size(64, 16);
117            this.ckShade.TabIndex = 3;
118            this.ckShade.Text = "Shade";
119            this.ckShade.CheckedChanged += new System.EventHandler(this.ckShade_CheckedChanged);
120            // 
121            // groupBox1
122            // 
123            this.groupBox1.Controls.AddRange(new System.Windows.Forms.Control[] {
124                                                                                    this.opPerennial,
125                                                                                    this.opVegetable,
126                                                                                    this.opAnnual});
127            this.groupBox1.Location = new System.Drawing.Point(8, 40);
128            this.groupBox1.Name = "groupBox1";
129            this.groupBox1.Size = new System.Drawing.Size(120, 120);
130            this.groupBox1.TabIndex = 0;
131            this.groupBox1.TabStop = false;
132            this.groupBox1.Text = "Garden type";
133            // 
134            // opPerennial
135            // 
136            this.opPerennial.Location = new System.Drawing.Point(16, 72);
137            this.opPerennial.Name = "opPerennial";
138            this.opPerennial.Size = new System.Drawing.Size(80, 16);
139            this.opPerennial.TabIndex = 2;
140            this.opPerennial.Text = "Perennial";
141            this.opPerennial.CheckedChanged += new System.EventHandler(this.opPerennial_CheckedChanged);
142            // 
143            // opAnnual
144            // 
145            this.opAnnual.Location = new System.Drawing.Point(16, 24);
146            this.opAnnual.Name = "opAnnual";
147            this.opAnnual.Size = new System.Drawing.Size(88, 16);
148            this.opAnnual.TabIndex = 0;
149            this.opAnnual.Text = "Annual";
150            this.opAnnual.CheckedChanged += new System.EventHandler(this.opAnnual_CheckedChanged);
151            // 
152            // Form1
153            // 
154            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
155            this.ClientSize = new System.Drawing.Size(368, 237);
156            this.Controls.AddRange(new System.Windows.Forms.Control[] {
157                                                                          this.ckShade,
158                                                                          this.ckBorder,
159                                                                          this.ckCenter,
160                                                                          this.gdPic1,
161                                                                          this.groupBox1});
162            this.Name = "Form1";
163            this.Text = "Garden planner";
164            this.groupBox1.ResumeLayout(false);
165            this.ResumeLayout(false);
166
167        }
168        #endregion
169
170        /**//// <summary>
171        /// The main entry point for the application.
172        /// </summary>
173        [STAThread]
174        static void Main() 
175        {
176            Application.Run(new Form1());
177        }
178
179        
180        private void opAnnual_CheckedChanged(object sender, EventArgs e) {
181            setGarden( new AnnualGarden ());
182        }
183        //-----
184        private void opVegetable_CheckedChanged(object sender, EventArgs e) {
185            setGarden( new VeggieGarden ());
186        }
187        //-----
188        private void opPerennial_CheckedChanged(object sender, EventArgs e) {
189            setGarden( new PerennialGarden ());
190        }        
191        //-----
192        private void setGarden(Garden gd) {
193            garden = gd;            //save current garden
194            gdPic1.setGarden ( gd);    //tell picture bos
195            gdPic1.Refresh ();        //repaint it
196            ckCenter.Checked =false;    //clear all
197            ckBorder.Checked = false;    //check
198            ckShade.Checked = false;    //boxes
199        }
200        private void ckCenter_CheckedChanged(object sender, System.EventArgs e) {
201            garden.setCenter ();
202            gdPic1.Refresh ();
203        }
204        //-----
205        private void ckBorder_CheckedChanged(object sender, System.EventArgs e) {
206            garden.setBorder();
207            gdPic1.Refresh ();
208        }
209        //-----
210        private void ckShade_CheckedChanged(object sender, System.EventArgs e) {
211            garden.setShade ();
212            gdPic1.Refresh ();
213        }
214    }
215}
216