摘要:FactorySupport Facility允许我们使用已经存在的工厂来创建组件的实例,可以把已经存在的对象模型加入到容器中,以便它能够使用自动装配。它使用了以下两种处理策略:
1
.使用访问器来访问组件的实例
2
.使用静态方法或者实例方式来访问组件的实例
主要内容
1
.概述
2
.为什么需要FactorySupport Facility
3
.如何使用
4
.常见的配置示例
5
.实现原理浅析
一.概述
FactorySupport Facility
允许我们使用已经存在的工厂来创建组件的实例,可以把已经存在的对象模型加入到容器中,以便它能够使用自动装配。它使用了以下两种处理策略:
1
.通过访问器来访问组件的实例
2
.通过静态方法或者实例方式来访问组件的实例
二.为什么需要FactorySupport Facility
为了回答这个问题,我们先来看一个简单的使用工厂的例子,如下代码所示:
public
interface
IComponent
{
void Display();
}
public class MyComponent : IComponent
{
public MyComponent()
{
}
public void Display()
{
Console.WriteLine("MyComponent");
}
}
public class MyFactory
{
public MyFactory()
{
}
public IComponent Create()
{
return new MyComponent();
}
}
{
void Display();
}
public class MyComponent : IComponent
{
public MyComponent()
{
}
public void Display()
{
Console.WriteLine("MyComponent");
}
}
public class MyFactory
{
public MyFactory()
{
}
public IComponent Create()
{
return new MyComponent();
}
}
现在要在程序中使用
MyComponent的实例,简单一点会这样去写:
public
class
App
{
static void Main()
{
MyFactory factory = new MyFactory();
IComponent comp = factory.Create();
comp.Display();
}
}
{
static void Main()
{
MyFactory factory = new MyFactory();
IComponent comp = factory.Create();
comp.Display();
}
}
正如你所看到的,在程序中使用
new关键字创建了一个工厂的实例,再由工厂得到组件的实例。现在我们看使用
FactorySupport Facility后带来了什么好处。工厂和组件的代码不变,仍然是:
public
interface
IComponent
{
void Display();
}
public class MyComponent : IComponent
{
public MyComponent()
{
}
public void Display()
{
Console.WriteLine("MyComponent");
}
}
public class MyFactory
{
public MyFactory()
{
}
public IComponent Create()
{
return new MyComponent();
}
}
{
void Display();
}
public class MyComponent : IComponent
{
public MyComponent()
{
}
public void Display()
{
Console.WriteLine("MyComponent");
}
}
public class MyFactory
{
public MyFactory()
{
}
public IComponent Create()
{
return new MyComponent();
}
}
配置文件,现在你可以不用理解怎么去配置,后面会讲到。
<?
xml version="1.0" encoding="utf-8"
?>
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="myfactory" type ="FactorySupportDemo.MyFactory,FactorySupportDemo" />
< component id ="mycomp" type ="FactorySupportDemo.MyComponent,FactorySupportDemo"
factoryId ="myfactory" factoryCreate ="Create" ></ component >
</ components >
</ configuration >
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="myfactory" type ="FactorySupportDemo.MyFactory,FactorySupportDemo" />
< component id ="mycomp" type ="FactorySupportDemo.MyComponent,FactorySupportDemo"
factoryId ="myfactory" factoryCreate ="Create" ></ component >
</ components >
</ configuration >
使用组件的实例
public
class
App
{
static void Main()
{
IWindsorContainer container = new WindsorContainer("../../Basic.xml");
IComponent instance = (IComponent) container["mycomp"];
instance.Display();
}
}
{
static void Main()
{
IWindsorContainer container = new WindsorContainer("../../Basic.xml");
IComponent instance = (IComponent) container["mycomp"];
instance.Display();
}
}
看到了吗?我们并没有使用
new关键字创建任何对象,只是把工厂、组件等通过配置文件抛给了
IOC容器,再从容器中往外取的时候,就可以直接取到组件的实例,这些实例是由工厂自动创建的,这正是
FactorySupport Facility的作用。
三.如何使用
知道了为什么需要FactorySupport Facility之后,下面就来看如何使用Facility。在前面的代码中大家都已经看到了,使用FactorySupport Facility是非常的简单。
1
.加入FactorySupport Facility到容器中,可以使用代码加入也可以使用配置文件。
使用代码加入:
IWindsorContainer container
=
new
WindsorContainer(
"
../../Basic.xml
"
);
container.AddFacility( " factorysupport " , new Castle.Facilities.FactorySupport.FactorySupportFacility());
container.AddFacility( " factorysupport " , new Castle.Facilities.FactorySupport.FactorySupportFacility());
使用配置文件:
<
facilities
>
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
2
.加入组件时指定使用的是哪种方式
如果使用访问器只需要指定访问器的名称就可以了:
<
component
id
="accessor.comp"
type ="Castle.Facilities.FactorySupport.Tests.Components.SingletonWithAccessor, Castle.Facilities.FactorySupport.Tests"
instance-accessor ="Instance" >
</ component >
type ="Castle.Facilities.FactorySupport.Tests.Components.SingletonWithAccessor, Castle.Facilities.FactorySupport.Tests"
instance-accessor ="Instance" >
</ component >
如果使用工厂方法,需要指定工厂
ID和工厂方法:
<
component
id
="mycomp"
type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" >
</ component >
type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" >
</ component >
四.常见的配置示例
这是一些常见的配置示例,来自于Castle自带的测试代码中。
1
.访问器配置示例
有这样一个单件类
public
class
SingletonWithAccessor
{
private static readonly SingletonWithAccessor instance = new SingletonWithAccessor();
private SingletonWithAccessor()
{
}
public static SingletonWithAccessor Instance
{
get { return instance; }
}
}
{
private static readonly SingletonWithAccessor instance = new SingletonWithAccessor();
private SingletonWithAccessor()
{
}
public static SingletonWithAccessor Instance
{
get { return instance; }
}
}
配置文件如下:
<?
xml version="1.0" encoding="utf-8"
?>
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="accessor.comp" type ="Castle.Facilities.FactorySupport.Tests.Components.SingletonWithAccessor, Castle.Facilities.FactorySupport.Tests"
instance-accessor ="Instance" ></ component >
</ components >
</ configuration >
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="accessor.comp" type ="Castle.Facilities.FactorySupport.Tests.Components.SingletonWithAccessor, Castle.Facilities.FactorySupport.Tests"
instance-accessor ="Instance" ></ component >
</ components >
</ configuration >
2
.普通工厂配置示例
组件类和工厂类如下
public
class
MyComp
{
public MyComp()
{
}
}
public class MyCompFactory
{
public MyComp Create()
{
return new MyComp();
}
}
{
public MyComp()
{
}
}
public class MyCompFactory
{
public MyComp Create()
{
return new MyComp();
}
}
配置文件如下:
<?
xml version="1.0" encoding="utf-8"
?>
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="mycompfactory" type ="Castle.Facilities.FactorySupport.Tests.Components.MyCompFactory, Castle.Facilities.FactorySupport.Tests" />
< component id ="mycomp" type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" ></ component >
</ components >
</ configuration >
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="mycompfactory" type ="Castle.Facilities.FactorySupport.Tests.Components.MyCompFactory, Castle.Facilities.FactorySupport.Tests" />
< component id ="mycomp" type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" ></ component >
</ components >
</ configuration >
3
.带参工厂配置示例
组件类和工厂类如下:
public
class
MyComp
{
private string storeName;
private IDictionary props;
internal MyComp()
{
}
internal MyComp(String storeName, IDictionary props)
{
this.storeName = storeName;
this.props = props;
}
public string StoreName
{
get { return storeName; }
}
public IDictionary Props
{
get { return props; }
}
}
public class MyCompFactory2
{
public MyCompFactory2()
{
}
public MyComp Create(String storeName, IDictionary props)
{
return new MyComp(storeName, props);
}
}
{
private string storeName;
private IDictionary props;
internal MyComp()
{
}
internal MyComp(String storeName, IDictionary props)
{
this.storeName = storeName;
this.props = props;
}
public string StoreName
{
get { return storeName; }
}
public IDictionary Props
{
get { return props; }
}
}
public class MyCompFactory2
{
public MyCompFactory2()
{
}
public MyComp Create(String storeName, IDictionary props)
{
return new MyComp(storeName, props);
}
}
配置文件如下:
<?
xml version="1.0" encoding="utf-8"
?>
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="mycompfactory" type ="Castle.Facilities.FactorySupport.Tests.Components.MyCompFactory2, Castle.Facilities.FactorySupport.Tests" ></ component >
< component id ="mycomp" type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" >
< parameters >
< storeName > MyStore </ storeName >
< props >
< dictionary >
< entry key ="key1" > item1 </ entry >
< entry key ="key2" > item2 </ entry >
</ dictionary >
</ props >
</ parameters >
</ component >
</ components >
</ configuration >
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="mycompfactory" type ="Castle.Facilities.FactorySupport.Tests.Components.MyCompFactory2, Castle.Facilities.FactorySupport.Tests" ></ component >
< component id ="mycomp" type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" >
< parameters >
< storeName > MyStore </ storeName >
< props >
< dictionary >
< entry key ="key1" > item1 </ entry >
< entry key ="key2" > item2 </ entry >
</ dictionary >
</ props >
</ parameters >
</ component >
</ components >
</ configuration >
4
.使用自动装配工厂配置示例
组件类和工厂类如下:
public
interface
IMyService
{
}
public class MyComp
{
private IMyService serv;
internal MyComp()
{
}
internal MyComp(IMyService serv)
{
this.serv = serv;
}
public IMyService Service
{
get { return serv; }
}
}
public class MyCompFactory3
{
public MyCompFactory3()
{
}
public MyComp Create(IMyService serv)
{
return new MyComp(serv);
}
}
{
}
public class MyComp
{
private IMyService serv;
internal MyComp()
{
}
internal MyComp(IMyService serv)
{
this.serv = serv;
}
public IMyService Service
{
get { return serv; }
}
}
public class MyCompFactory3
{
public MyCompFactory3()
{
}
public MyComp Create(IMyService serv)
{
return new MyComp(serv);
}
}
配置文件如下:
<?
xml version="1.0" encoding="utf-8"
?>
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="myserv" service ="Castle.Facilities.FactorySupport.Tests.Components.IMyService, Castle.Facilities.FactorySupport.Tests"
type ="Castle.Facilities.FactorySupport.Tests.Components.DefaultMyService, Castle.Facilities.FactorySupport.Tests" />
< component id ="mycompfactory" type ="Castle.Facilities.FactorySupport.Tests.Components.MyCompFactory3, Castle.Facilities.FactorySupport.Tests" ></ component >
< component id ="mycomp" type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" >
<!-- parameters is not necessary_u97 ?s it will auto wire --> </ component >
</ components >
</ configuration >
< configuration >
< facilities >
< facility id ="factorysupport" type ="Castle.Facilities.FactorySupport.FactorySupportFacility, Castle.MicroKernel" />
</ facilities >
< components >
< component id ="myserv" service ="Castle.Facilities.FactorySupport.Tests.Components.IMyService, Castle.Facilities.FactorySupport.Tests"
type ="Castle.Facilities.FactorySupport.Tests.Components.DefaultMyService, Castle.Facilities.FactorySupport.Tests" />
< component id ="mycompfactory" type ="Castle.Facilities.FactorySupport.Tests.Components.MyCompFactory3, Castle.Facilities.FactorySupport.Tests" ></ component >
< component id ="mycomp" type ="Castle.Facilities.FactorySupport.Tests.Components.MyComp, Castle.Facilities.FactorySupport.Tests"
factoryId ="mycompfactory" factoryCreate ="Create" >
<!-- parameters is not necessary_u97 ?s it will auto wire --> </ component >
</ components >
</ configuration >
五.实现原理浅析
FactorySupport Facility
的实现也是非常的简单,主要是通过两个
ComponentActivator
来实现,分别为AccessorActivator和FactoryActivator,根据配置文件的不同调用不同的Activator。
String instanceAccessor
=
model.Configuration.Attributes[
"
instance-accessor
"
];
String factoryId = model.Configuration.Attributes[ " factoryId " ];
String factoryCreate = model.Configuration.Attributes[ " factoryCreate " ];
if (instanceAccessor != null )
{
model.ExtendedProperties.Add( "instance.accessor", instanceAccessor );
model.CustomComponentActivator = typeof(AccessorActivator);
}
else if (factoryId != null )
{
model.ExtendedProperties.Add( "factoryId", factoryId );
model.ExtendedProperties.Add( "factoryCreate", factoryCreate );
model.CustomComponentActivator = typeof(FactoryActivator);
}
String factoryId = model.Configuration.Attributes[ " factoryId " ];
String factoryCreate = model.Configuration.Attributes[ " factoryCreate " ];
if (instanceAccessor != null )
{
model.ExtendedProperties.Add( "instance.accessor", instanceAccessor );
model.CustomComponentActivator = typeof(AccessorActivator);
}
else if (factoryId != null )
{
model.ExtendedProperties.Add( "factoryId", factoryId );
model.ExtendedProperties.Add( "factoryCreate", factoryCreate );
model.CustomComponentActivator = typeof(FactoryActivator);
}
本文转自lihuijun51CTO博客,原文链接:
http://blog.51cto.com/terrylee/67692
,如需转载请自行联系原作者