Design Pattern【2.3】抽象工厂模式

参考http://www.cnblogs.com/yuyijq/archive/2007/10/06/915185.html

　　http://www.cnblogs.com/zhenyulu/articles/36885.html

 

//抽象工厂类
namespace WindowsFormsApplication4
{
    public abstract class ComputerOperation
    {
        public abstract XP CreateXP();
        public abstract Linux CreateLinux();
    }
}

 

//具体工厂类Windows.cs
namespace WindowsFormsApplication4
{
    public class Windows:ComputerOperation
    {
        public override XP CreateXP()
        {
            return new WindowsXP();
        }
        public override Linux CreateLinux()
        {
            return new WindowsLinux();
        }
    }
}

 

namespace WindowsFormsApplication4
{
    //具体工厂类Mac.cs
    public class Mac:ComputerOperation
    {
        public override XP CreateXP()
        {
            return new MacXP();
        }
        public override Linux CreateLinux()
        {
            return new MacLinux();
        }
    }
}

 

//基类XP.cs
namespace WindowsFormsApplication4
{
    public abstract class XP
    {
        public abstract string showxp();
    }
}
//基类Linux.cs
namespace WindowsFormsApplication4
{
    public abstract class Linux
    {
        public abstract string linuxshow();
    }
}

 

//具体工厂类
namespace WindowsFormsApplication4
{
    public class WindowsXP:XP
    {
        public override string showxp()
        {
            return "u r using Windows XP Operation!";
        }
    }
}
namespace WindowsFormsApplication4
{
    class WindowsLinux : Linux
    {
        public override string linuxshow()
        {
            return "u r using Windows Linux Operation!";
        }
    }
}
namespace WindowsFormsApplication4
{
    public class MacXP : XP
    {
        public override string showxp()
        {
            return "u r using Mac XP Operation!";
        }
    }
}
namespace WindowsFormsApplication4
{
    public class MacLinux : Linux
    {
        public override string linuxshow()
        {
            return "u r using Mac Linux Operation!";
        }
    }
}

客户端代码：

private void button1_Click(object sender, EventArgs e)
        {
            string str = "";
            ComputerOperation co = new Windows();
            XP xp = co.CreateXP();
            str += xp.showxp();
            MessageBox.Show(str);
        }

 

改为以反射为手段的抽象工厂模式..

//抽象工厂类
namespace WindowsFormsApplication4
{
    public class ComputerOperation
    {
        //public abstract XP CreateXP();
       // public abstract Linux CreateLinux();
        private string _xp;
        private string _linux;
        public ComputerOperation(string type)
        {
            _xp = string.Format("WindowsFormsApplication4.{0}XP", type);
            _linux = string.Format("WindowsFormsApplication4.{0}Linux", type);
        }
        public XP CreateXP()
        {
            return (XP)helper(_xp);
        }
        public Linux CreateLinux()
        {
            return (Linux)helper(_linux);
        }
        private object helper( string classname)
        {
            return Assembly.Load("WindowsFormsApplication4").CreateInstance(classname);
        }
    }
    
}

除去了Window.cs和Mac.cs类

客户端代码变为：

private void button1_Click(object sender, EventArgs e)
        {
            string str = "";
            //ComputerOperation co = new Windows();
            //XP xp = co.CreateXP();
            //str += xp.showxp();
            ComputerOperation co = new ComputerOperation("Windows");
            str = co.CreateXP().show();
            MessageBox.Show(str);
        }

抽象工厂模式比较适用于后台数据库的切换，如从Orcal到SQL Server的切换，如果适用配置文件和反射的话，只需要更改配置文件即可！