目录
- 定义
- UML
- 参与者
- 示例
定义：
定义一个创建对象的接口,但是让子类来决定哪个类将被实例化。工厂方法让一个类实例化推迟到子类。
UML:
参与者：
产品(Project)角色:定义一个产品的接口。
具体产品(ConcreteProduct)角色： 实现这个产品角色接口的具体类。
工厂(Factory)角色：定义一个接口，用来创建产品。
具体工厂(ConcreteFactory)角色：实现工厂角色接口的具体类。
示例
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using System;
namespace DoFactory.GangOfFour.Factory.Structural
{
/// <summary>
/// MainApp startup class for Structural
/// Factory Method Design Pattern.
/// </summary>
class MainApp
{
/// <summary>
/// Entry point into console application.
/// </summary>
static void Main()
{
// An array of creators
Creator[] creators =
new Creator[2];
creators[0] =
new ConcreteCreatorA();
creators[1] =
new ConcreteCreatorB();
// Iterate over creators and create products
foreach (Creator creator
in creators)
{
Product product = creator.FactoryMethod();
Console.WriteLine("
Created {0}",
product.GetType().Name);
}
// Wait for user
Console.ReadKey();
}
}
/// <summary>
/// The 'Product' abstract class
/// </summary>
abstract class Product
{
}
/// <summary>
/// A 'ConcreteProduct' class
/// </summary>
class ConcreteProductA : Product
{
}
/// <summary>
/// A 'ConcreteProduct' class
/// </summary>
class ConcreteProductB : Product
{
}
/// <summary>
/// The 'Creator' abstract class
/// </summary>
abstract class Creator
{
public abstract Product FactoryMethod();
}
/// <summary>
/// A 'ConcreteCreator' class
/// </summary>
class ConcreteCreatorA : Creator
{
public override Product FactoryMethod()
{
return new ConcreteProductA();
}
}
/// <summary>
/// A 'ConcreteCreator' class
/// </summary>
class ConcreteCreatorB : Creator
{
public override Product FactoryMethod()
{
return new ConcreteProductB();
}
}
}
Output：
Created ConcreteProductA
Created ConcreteProductB
实际运用：
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/// <summary>
/// 产品接口
/// </summary>
public interface ICar
{
void OpenDoor();
}
/// <summary>
/// 宝马车
/// </summary>
public class BaoMaCar : ICar
{
public void OpenDoor()
{
Console.WriteLine("
打开宝马车门");
}
}
/// <summary>
/// 奥迪车
/// </summary>
public class AodiCar : ICar
{
public void OpenDoor()
{
Console.WriteLine("
打开奥迪车门");
}
}
/// <summary>
/// 工厂接口，用来创建哪个车
/// </summary>
public interface IFactory
{
ICar Create();
}
/// <summary>
/// 宝马工厂
/// </summary>
public class BaoMaFactory : IFactory
{
public ICar Create()
{
return new BaoMaCar();
}
}
/// <summary>
/// 奥迪工厂
/// </summary>
public class AoDiFactory : IFactory
{
public ICar Create()
{
return new AodiCar();
}
}
static void Main(
string[] args)
{
IFactory factory =
new AoDiFactory();
ICar car = factory.Create();
car.OpenDoor();
Console.Read();
}
OutPut:
打开奥迪车门