有一个比较好理解的例子,在这跟大家介绍下:
1.如果一个后花园只种蔬菜类,那么就用简单工厂就可以了.
2.如果后花园蔬菜品种繁多.得用工厂方法才可以,把共有的东西抽象出来.
3.如果要扩大后花园的规模,比如一个在北方,一个在南方,这样工厂方法就无法实现了,就应当用抽象工厂,把各种各样的植物,又组成一个后花园.
所以我个人认为,简单工厂是一个工厂只生产一类的产品,面对的是具体的类,工厂方法是可以生产不同的产品,把公共的方法抽象出来,然后进行创建各种各样的产品.抽象工厂把几种产品划出共同的东西,把相互依赖的对象抽象出来,只要实现这些接口就可以得到不同的产品.
具体例子:
1.简单工厂:
using System;
public interface ICar
{
void run();
}
public class BMWCar : ICar
{
public void run()
{
Console.WriteLine("BMWCar run");
}
}
public class BenzCar : ICar
{
public void run()
{
Console.WriteLine("BenzCar run");
}
}
public class Driver
{
public static ICar DriverCar(string carType)
{
switch (carType)
{
case "BMWCar": return new BMWCar();
case "BenzCar": return new BenzCar();
default: throw new Exception();
}
}
}
public class Client
{
public static void Main()
{
ICar myCar = Driver.DriverCar("BenzCar");
myCar.run();
Console.Read();
}
}
心得:优点是只要实现共有的接口就可以实现不同车跑的方式.但缺点就是要判断哪一种车,造成要修改Driver 类
2.工厂方法:
using System;
public interface ICar
{
void run();
}
public class BMWCar : ICar
{
public void run()
{
Console.WriteLine("BMWCar run");
}
}
public class BenzCar : ICar
{
public void run()
{
Console.WriteLine("BenzCar run");
}
}
public abstract class Driver
{
public abstract ICar DriverCar();
}
public class BMWDriver : Driver
{
public override ICar DriverCar()
{
return new BMWCar();
}
}
public class BenzDriver : Driver
{
public override ICar DriverCar()
{
return new BenzCar();
}
}
class Client
{
public static void Main()
{
Driver myDriver = new BenzDriver();
ICar myCar = myDriver.DriverCar();
myCar.run();
Console.Read();
}
}
心得:优点是符合了开放-封闭原则(OCP),从整体上还看不出什么缺点.
3.抽象工厂:
using System;
public interface IBusinessCar
{
void run();
}
public interface ISportCar
{
void run();
}
public class BMWBusinessCar : IBusinessCar
{
public void run()
{
Console.WriteLine("BMWCar run");
}
}
public class BenzBusinessCar : IBusinessCar
{
public void run()
{
Console.WriteLine("BenzBusinessCar run");
}
}
public class BMWSportCar:ISportCar
{
public void run()
{
Console.WriteLine("BMWSportCar run");
}
}
public class BenzSportCar:ISportCar
{
public void run()
{
Console.WriteLine("BenzSportCar run");
}
}
public interface IDriver
{
IBusinessCar BusinessCarDriver();
ISportCar SportCarDriver();
}
public class BMWDriver:IDriver
{
public IBusinessCar BusinessCarDriver()
{
return new BMWBusinessCar();
}
public ISportCar SportCarDriver()
{
return new BMWSportCar();
}
}
public class BenzDriver:IDriver
{
public IBusinessCar BusinessCarDriver()
{
return new BenzBusinessCar();
}
public ISportCar SportCarDriver()
{
return new BenzSportCar();
}
}
class Client
{
public static void Main()
{
IDriver myDriver =new BenzDriver();
ISportCar myCar = myDriver.SportCarDriver();
myCar.run();
Console.Read();
}
}
心得:抽象方法似乎达到了完美境界.把开奔驰的司机和开宝马的司机的公共方法抽象出来,并对不同的司机创建不同的类,到时候不管是开什么车的司机随你添加.它们唯一的共同点都是开车.