设计模式学习摘要－抽象工厂

以日志记录实现为例：

具体实现日志类
1。定义一个抽象的日志Log
public abstract class Log
{
public abstract void Write();
}
2。定义两个具体的日志类
public class EventLog:Log
{
public override void Write()
{
Console.WriteLine("EventLog write sucess !");
}
}
public class FileLog:Log
{
public override void Write()
{
Console.WriteLine("FileLog write sucess !");
}
}
具体实现工厂类
1。定义一个抽象工厂类LogFactory
public abstract class LogFactory
{
public abstract Log Create();
}
2。定义两个具体的工厂类
public class EventFactory:LogFactory
{
public override EventLog Create()
{
return new EventLog();
}
}
public class FileFactory:LogFactory
{
public override FileLog Create()
{
return new FileLog();
}
}

应用程序中调用
public class App
{
public static void Main(string[] args)
{
LogFactory factory=new EventFactory();//
Log log=factory.Create();//
log.Write();
}
}
利用发射机制进一步修改
<appSettings>
add key="factoryName" value="EventFactory"></add>
</appSettings>

pubic class App
{
public static void Main(string[] args)
{
string strfactoryName = ConfigurationSettings.AppSettings["factoryName"];
LogFactory factory;
factory = (LogFactory)Assembly.Load("FactoryMethod").CreateInstance("FactoryMethod." + strfactoryName);
Log log = factory.Create();
log.Write();
}
}

参考资料：
http://terrylee.cnblogs.com/archive/2006/01/04/310716.html