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();
}
}
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();

}
}
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();
}
}
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
>
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();

}
}
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());
使用配置文件:
<
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
>
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
>
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; }
}
}
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
>
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();
}
}
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
>
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);
}
}
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
>
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);
}
}
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
>
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);

}
好了,关于
FactorySupport Facility就介绍到这儿,更多
Castle的文章您可以访问《
Castle 开发系列文章》。
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