Csharp/CSharp Tutorial/Design Patterns/Factory Pattern

Abstract Factory

<source lang="csharp">using System;

 public class AComputer: Computer
 {
   public override void ComputerBrand()
   {
     Console.WriteLine ("A Computer.");
   }
   public AComputer(){;}
 }
 public class AComputerDesk: ComputerDesk
 {
   public override void ComputerDeskBrand()
   {
     Console.WriteLine("A Computer cap.");
   }
   public AComputerDesk(){;}
 }
 public class AComputerFactory: ComputerFactory
 {
   public override Computer BuildComputer()
   {
     Computer rad = new AComputer();
     rad.ruputerBrand();
     return rad;
   }
   public override ComputerDesk BuildComputerDesk()
   {
     ComputerDesk cap = new AComputerDesk();
     cap.ruputerDeskBrand();
     return cap;
   }
       
   public AComputerFactory(){;}
 }
 public class BComputer:Computer
 {
   public override void ComputerBrand()
   {
     Console.WriteLine ("B Computer.");
   }
   
   
   public BComputer(){;}
 }
 public class BComputerDesk: ComputerDesk
 {
     
   public override void ComputerDeskBrand()
   {
     Console.WriteLine("B Computer cap.");
   }
   public BComputerDesk(){;}
 }
 public class BComputerFactory: ComputerFactory
 {
   
   public override Computer BuildComputer()
   {
     Computer rad = new  BComputer();
     rad.ruputerBrand();
     return rad;
   }
   public override ComputerDesk BuildComputerDesk()
   {
     ComputerDesk cap = new BComputerDesk();
     cap.ruputerDeskBrand();
     return cap;
   }
   
   public BComputerFactory(){;}
 }
 public class CComputer: Computer
 {
   
   public override void ComputerBrand()
   {
     Console.WriteLine ("C Computer.");
   }
 
   public CComputer() {;}
 }
 public class CComputerDesk: ComputerDesk
 {
   
   public override void ComputerDeskBrand()
   {
     Console.WriteLine("C Computer cap.");
   }
   
   public CComputerDesk(){;}
 }
   public class CComputerFactory : ComputerFactory
 {
   
   public override Computer BuildComputer()
   {
     Computer rad = new  CComputer();
     rad.ruputerBrand();
     return rad;
   }
   public override ComputerDesk BuildComputerDesk()
   {
     ComputerDesk cap = new CComputerDesk();
     cap.ruputerDeskBrand();
     return cap;
   }
   
   public CComputerFactory(){;}
 }
 public abstract class Computer
 {
   public abstract void ComputerBrand();
 }
 public abstract class ComputerDesk
 {
   public abstract void ComputerDeskBrand();
 }
 public abstract class ComputerFactory
 {
       public abstract Computer BuildComputer();
   public abstract ComputerDesk BuildComputerDesk();
 }
 public class WorkOrder
 {
       public void AssembleComputer(ComputerFactory fact)
   {
     Computer rad = fact.BuildComputer();
     ComputerDesk cap = fact.BuildComputerDesk();
     this.Assemble();
   }
   
   private void Assemble()
   {
     Console.WriteLine ("Assembling Computer and cap.");
     Console.WriteLine();
   }
   
   public WorkOrder(){;}
 }
 class Client
 {
   
   static void Main(string[] args)
   {
           ComputerFactory factoryOne = new AComputerFactory();
     WorkOrder workOne = new WorkOrder();
     workOne.AssembleComputer(factoryOne);
       
           ComputerFactory factoryTwo = new BComputerFactory();
     WorkOrder workTwo = new WorkOrder();
     workTwo.AssembleComputer(factoryTwo);
           ComputerFactory factoryThree = new CComputerFactory();
     WorkOrder workThree = new WorkOrder();
     workThree.AssembleComputer(factoryThree);
   }
   
 }</source>

Factory Method Patterns

<source lang="csharp">using System; using System.Collections;

 public abstract class Section
 {
   public abstract void SomeSection();
 }
 public class TitleSection: Section
 {
   
   public override void SomeSection()
   {
     Console.WriteLine("title.");
   }  
       
   public TitleSection(){;}
   
 }
 public class HeaderSection: Section
 {
   public override void SomeSection()
   {
     Console.WriteLine("header.");
   }
   public HeaderSection(){;}
 }
 public class FooterSection: Section
 {
       public override void SomeSection()
       {
           Console.WriteLine("footer.");
       }
   public FooterSection(){;}
 }
 public class MenuSection: Section
 {
   public override void SomeSection()
   {
     Console.WriteLine("menu.");
       }
           
   public MenuSection(){;}
 }
 public class CatalogPage: Page
 {
   public override void AddSection(){
     this.pageCompositor.Clear();
     this.pageCompositor.Add(new TitleSection());
     this.pageCompositor.Add(new FooterSection());
   }
   public override void DisplayPage(){
     Console.WriteLine("Catalog page contains:");
     foreach(Section c in this.pageCompositor)
       c.SomeSection();
   }
   public CatalogPage()
   {
     this.AddSection();
   }
 }
 public class ManualPage: Page
 {
   public override void AddSection()
   {
     this.pageCompositor.Clear();
     this.pageCompositor.Add(new MenuSection());
     this.pageCompositor.Add(new FooterSection());
     this.pageCompositor.Add(new HeaderSection());
   }
   public override void DisplayPage()
   {
     Console.WriteLine("Manual page contains:");
       foreach(Section c in this.pageCompositor)
       c.SomeSection();
     Console.WriteLine();
   }
   public ManualPage(){;}
 }
 public abstract class Page
 {
   protected ArrayList pageCompositor = new ArrayList();
   public abstract void AddSection();
   public abstract void DisplayPage();
 }  
 class Client
 {
   static void Main(string[] args)
   {
     Page p = new  CatalogPage();
     p.AddSection();
     p.DisplayPage();
 
     p = new ManualPage();
     p.AddSection();
     p.DisplayPage();
     
   }
 }</source>

Use a static class factory

<source lang="csharp">using System;

class MyClass {

 int a, b; 

 // Create a class factory for MyClass. 
 static public MyClass factory(int i, int j) { 
   MyClass t = new MyClass(); 
   
   t.a = i; 
   t.b = j; 

   return t; // return an object 
 } 

 public void show() { 
   Console.WriteLine("a and b: " + a + " " + b); 
 } 

}

class MainClass {

 public static void Main() {   
   int i, j; 

   // generate objects using the factory 
   for(i=0, j=10; i < 10; i++, j--) { 
     MyClass ob = MyClass.factory(i, j); // get an object 
     ob.show(); 
   } 
      
   Console.WriteLine();    
 } 

}</source>

a and b: 0 10
a and b: 1 9
a and b: 2 8
a and b: 3 7
a and b: 4 6
a and b: 5 5
a and b: 6 4
a and b: 7 3
a and b: 8 2
a and b: 9 1