建造者模式

在软件系统中，有时候面临着“一个复杂对象”的创建工作，其通常由各个部分的子对象用一定的算法构成；由于需求的变化，这个复杂对象的各个部分经常面临着剧烈的变化，但是将它们组合在一起的算法确相对稳定。如何应对这种变化？如何提供一种“封装机制”来隔离出“复杂对象的各个部分”的变化，从而保持系统中的“稳定构建算法”不随着需求改变而改变？这就是要说的建造者模式。

using System;

namespace MyApp

{

class Program

{

static void Main()

{

Animal person = new Person();

CreateAnimal createAnimal = new CreateAnimal(person);

createAnimal.Create();

Console.WriteLine();

Animal monkey = new Monkey();

createAnimal = new CreateAnimal(monkey);

createAnimal.Create();

Console.ReadKey();

}

}

abstract class Animal

{

public abstract void AddBody();

public abstract void AddHand();

public abstract void AddLeg();

public abstract void AddHead();

}

class Person : Animal

{

public override void AddBody()

{

Console.WriteLine("Person's body was created...");

}

public override void AddHand()

{

Console.WriteLine("Person's hands were created...");

}

public override void AddLeg()

{

Console.WriteLine("Person's legs were created...");

}

public override void AddHead()

{

Console.WriteLine("Person's head was created...");

}

}

class Monkey : Animal

{

public override void AddBody()

{

Console.WriteLine("Monkey's body was created...");

}

public override void AddHand()

{

Console.WriteLine("Monkey's hands were created...");

}

public override void AddLeg()

{

Console.WriteLine("Monkey's legs were created...");

}

public override void AddHead()

{

Console.WriteLine("Monkey's head was created...");

}

}

class CreateAnimal

{

Animal animal;

public CreateAnimal(Animal theAnimalInstance)

{

animal = theAnimalInstance;

}

public void Create()

{

animal.AddBody();

animal.AddHand();

animal.AddLeg();

animal.AddHead();

}

}

}