c# – 这是表示抽象工厂模式的一个很好的例子

想检查这是否是表示抽象工厂模式的好例子.
这是主题
戴尔(工厂)生产xps(产品)
戴尔(工厂)生产inspiron(产品)
惠普(工厂)使特使(产品)
hp(工厂)制造presario(产品)

BestBuy销售电脑.

//Abstract factory
abstract class ComputerFactory
{
    public abstract Computer BuildComputer(Computer.ComputerType compType);
}

//Concrete factory
class Dell : ComputerFactory
{
    public override Computer BuildComputer(Computer.ComputerType compType)
    {
        if (compType == Computer.ComputerType.xps)
            return (new xps());
        else if (compType == Computer.ComputerType.inspiron)
            return new inspiron();
        else
            return null;
    }
}

//Concrete factory
class Hp : ComputerFactory
{
    public override Computer BuildComputer(Computer.ComputerType compType)
    {
        if (compType == Computer.ComputerType.envoy)
            return (new envoy());
        else if (compType == Computer.ComputerType.presario)
            return new presario();
        else
            return null;
    }
}

//Abstract product
public abstract class Computer
{
    public abstract string Mhz { get; set; }
    public enum ComputerType
    {
        xps,inspiron,envoy,presario
    }
}

//Concrete product for DELL
public class xps : Computer
{
    string _mhz = string.Empty;

    public override string Mhz
    {
        get
        {
            return _mhz;
        }
        set
        {
            _mhz = value;
        }
    }
}

//Concrete product for DELL
public class inspiron : Computer
{
    string _mhz = string.Empty;

    public override string Mhz
    {
        get
        {
            return _mhz;
        }
        set
        {
            _mhz = value;
        }
    }
}

//Concrete product for HP
public class envoy : Computer
{
    string _mhz = string.Empty;

    public override string Mhz
    {
        get
        {
            return _mhz;
        }
        set
        {
            _mhz = value;
        }
    }
}

//Concrete product for HP
public class presario : Computer
{
    string _mhz = string.Empty;

    public override string Mhz
    {
        get
        {
            return _mhz;
        }
        set
        {
            _mhz = value;
        }
    }
}

public class BestBuy
{
    ComputerFactory compFactory;
    Computer comp;
    public BestBuy(Computer.ComputerType compType)
    {
        if (compType == Computer.ComputerType.xps || compType == Computer.ComputerType.inspiron)
            compFactory = new Dell();
        else
            compFactory = new Hp();

        comp = compFactory.BuildComputer(compType);
    }

    public Computer Sell()
    {
        return comp;
    }
}

提前致谢.

解决方法

这是模式部分的一个很好的例子.对象的基本构造是一个不错的例子,但逻辑依赖于单个Computer.ComputerType枚举.这个枚举需要事先知道每个工厂暴露的每种类型的计算机.

通常,使用抽象工厂的动机是从图片中抽象出这种类型的硬编码要求.最好不要使用单个枚举,而是添加ComputerType类,并允许工厂返回可用类型的集合.然后,您可以使用返回的ComputerType来构建新系统.

这允许您在不更改API的情况下添加其他工厂,这是抽象工厂模式的主要优点之一.阅读Abstract Factory Pattern – 其中一个要点是：

The client does not know (or care) which concrete objects it gets from each of these internal factories since it uses only the generic interfaces of their products.

在这种情况下,您将已知类型“硬编码”到枚举中,这违反了模式的这一部分.

c# – 这是表示抽象工厂模式的一个很好的例子

解决方法

猜你在找的C#相关文章