摘要:从本文开始,我们将逐一实践Castle IOC中的Facility,在前面我们说过,Facility它是带有注入性质的。有时我们会遇到这样的问题,当一个组件满足一定的依赖关系之后,让它自动运行,比如说启动一个窗体或者启动某种服务,本文我们就来看如何使用Startable Facility让一个实现了接口IStartable的组件自动运行,以及不实现IStartable接口的组件如何在满足依赖后自动运行。
主要内容
1.Startable Facility概述
2.实现IStartable接口使用详解
3.不实现IStartable接口使用
一.Startable Facility概述
在开始使用Startable Facility之前,我们先了解一下它做了什么事情,它可以让一个组件在满足依赖关系之后自动启动或者停止。官方网站中提供的Startable Facility的有关信息:
Facility Information
|
Uses Proxy
|
No
|
Requires Configuration
|
No
|
Uses Attributes
|
No
|
Version
|
Beta 2
|
二.实现IStartable接口使用详解
Startable Facility的使用可以说是非常地简单,只要我们的组件实现了IStartable接口就可以了。现在我们还有一个Program类,它专门控制Server的启动和停止,我们希望在它的依赖关系满足后,让Server自动启动。很简单,我们让Program类实现IStartable接口:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
/**//// <summary>
![](/Images/OutliningIndicators/InBlock.gif)
/// Author:Terrylee
![](/Images/OutliningIndicators/InBlock.gif)
/// Date:2006年4月28日
![](/Images/OutliningIndicators/InBlock.gif)
/// From:http://terrylee.cnblogs.com
![](/Images/OutliningIndicators/InBlock.gif)
/// </summary>![](/Images/OutliningIndicators/None.gif)
public class Program : IStartable
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ContractedBlock.gif)
{
private Server _server;
![](/Images/OutliningIndicators/InBlock.gif)
public Program(Server server)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
this._server = server;
}
![](/Images/OutliningIndicators/InBlock.gif)
public void Start()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
_server.Start();
}
![](/Images/OutliningIndicators/InBlock.gif)
public void Stop()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
_server.Stop();
}
}
注意这个里面的Start()和Stop()方法就是要实现接口中的方法,我们在Start()方法中启动服务器,在Stop()方法中停止服务器。并且这个类依赖于Server类,也就是要满足它的依赖关系,还需要有一个Server组件。服务器Server,它需要一个Host和Port:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
/**//// <summary>
![](/Images/OutliningIndicators/InBlock.gif)
/// Author:Terrylee
![](/Images/OutliningIndicators/InBlock.gif)
/// Date:2006年4月28日
![](/Images/OutliningIndicators/InBlock.gif)
/// From:http://terrylee.cnblogs.com
![](/Images/OutliningIndicators/InBlock.gif)
/// </summary>![](/Images/OutliningIndicators/None.gif)
public class Server
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ContractedBlock.gif)
{
private string _host;
![](/Images/OutliningIndicators/InBlock.gif)
private int _port;
![](/Images/OutliningIndicators/InBlock.gif)
public Server(string host,int port)
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
this._host = host;
![](/Images/OutliningIndicators/InBlock.gif)
this._port = port;
}
![](/Images/OutliningIndicators/InBlock.gif)
public void Start()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
Console.WriteLine("Server {0}:{1} Start
",_host,_port);
![](/Images/OutliningIndicators/InBlock.gif)
Console.ReadLine();
}
![](/Images/OutliningIndicators/InBlock.gif)
public void Stop()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
Console.WriteLine("Server {0}:{1} Stop
",_host,_port);
![](/Images/OutliningIndicators/InBlock.gif)
Console.ReadLine();
}
}
同时对于这个Server类来说,它需要一个配置文件:
<!--From:http://terrylee.cnblogs.com-->
![](/Images/OutliningIndicators/None.gif)
<?xml version="1.0" encoding="utf-8" ?>
![](/Images/OutliningIndicators/None.gif)
<configuration>
![](/Images/OutliningIndicators/None.gif)
<components>
![](/Images/OutliningIndicators/None.gif)
<component id="server">
![](/Images/OutliningIndicators/None.gif)
<parameters>
![](/Images/OutliningIndicators/None.gif)
<host>localhost</host>
![](/Images/OutliningIndicators/None.gif)
<port>110</port>
![](/Images/OutliningIndicators/None.gif)
</parameters>
![](/Images/OutliningIndicators/None.gif)
</component>
![](/Images/OutliningIndicators/None.gif)
</components>
![](/Images/OutliningIndicators/None.gif)
</configuration>
需要注意的是这个配置文件跟Startable Facility没有任何关系,我们在配置文件中看不到任何和Startable Facility有关的代码。它只是一个普通的Castle IOC配置文件,因为我们在概述中已经说过了,Startable Facility是不需要配置文件的。好了,现在我们来看客户程序的使用:
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
/**//// <summary>
![](/Images/OutliningIndicators/InBlock.gif)
/// Author:Terrylee
![](/Images/OutliningIndicators/InBlock.gif)
/// Date:2006年4月28日
![](/Images/OutliningIndicators/InBlock.gif)
/// From:http://terrylee.cnblogs.com
![](/Images/OutliningIndicators/InBlock.gif)
/// </summary>![](/Images/OutliningIndicators/None.gif)
public class App
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ContractedBlock.gif)
{
public static void Main()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
//创建Windsor容器
![](/Images/OutliningIndicators/InBlock.gif)
IWindsorContainer container = new WindsorContainer(new XmlInterpreter("http://www.cnblogs.com/BasicUsage.xml"));
![](/Images/OutliningIndicators/InBlock.gif)
//添加Facility
![](/Images/OutliningIndicators/InBlock.gif)
container.AddFacility("startable", new StartableFacility());
![](/Images/OutliningIndicators/InBlock.gif)
//添加Program组件 (A)
![](/Images/OutliningIndicators/InBlock.gif)
container.AddComponent("program", typeof(Program));
![](/Images/OutliningIndicators/InBlock.gif)
//添加Server组件(B)
![](/Images/OutliningIndicators/InBlock.gif)
container.AddComponent("server", typeof(Server));
}
}
可以看到,在这个过程中,没有一点多余的代码,首先添加Startable Facility到容器中,然后添加Program组件,即执行到上面的A句的时候,因为还没有添加Server组件,不满足它的依赖关系,所以它无法启动,当添加完Server组件后,即执行了B句后,满足了它的依赖关系,这个它才会自动执行。
三.不实现IStartable接口使用
这是个很多人都忽略的问题,开始时我一直认为只有实现了IStartable接口才能使用Startable Facility,后来我在读它的源码时发现了一个问题,它不仅仅是判断组件是否实现了这个接口,如果组件有Startable特性也可以在满足依赖性后自动启动,这个在下一篇原理分析篇中我会介绍到。然后我就去查找这方面的资料,很可惜的网上从来没有介绍这种使用方法,我从它的TestCase找到了一点下面的代码,供有兴趣的朋友参考一下:
没有实现IStartable接口的组件:
[Transient]
![](/Images/OutliningIndicators/None.gif)
public class NoInterfaceStartableComponent
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ContractedBlock.gif)
{
private bool _Started = false;
![](/Images/OutliningIndicators/InBlock.gif)
private bool _Stopped = false;
![](/Images/OutliningIndicators/InBlock.gif)
public void Start()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
_Started = true;
}
![](/Images/OutliningIndicators/InBlock.gif)
public void Stop()
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
_Stopped = true;
}
![](/Images/OutliningIndicators/InBlock.gif)
public bool Started
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
get
{ return _Started; }
}
![](/Images/OutliningIndicators/InBlock.gif)
public bool Stopped
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
![](/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
get
{ return _Stopped; }
}
}
测试代码:
[Test]
![](/Images/OutliningIndicators/None.gif)
public void TestComponentWithNoInterface()
![](/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](/Images/OutliningIndicators/ContractedBlock.gif)
{
IKernel kernel = new DefaultKernel();
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
MutableConfiguration compNode = new MutableConfiguration("component");
![](/Images/OutliningIndicators/InBlock.gif)
compNode.Attributes["id"] = "b";
![](/Images/OutliningIndicators/InBlock.gif)
compNode.Attributes["startable"] = "true";
![](/Images/OutliningIndicators/InBlock.gif)
compNode.Attributes["startMethod"] = "Start";
![](/Images/OutliningIndicators/InBlock.gif)
compNode.Attributes["stopMethod"] = "Stop";
![](/Images/OutliningIndicators/InBlock.gif)
kernel.ConfigurationStore.AddComponentConfiguration("b", compNode);
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
kernel.AddFacility( "startable", new StartableFacility() );
![](/Images/OutliningIndicators/InBlock.gif)
kernel.AddComponent( "b", typeof(NoInterfaceStartableComponent) );
![](/Images/OutliningIndicators/InBlock.gif)
NoInterfaceStartableComponent component = kernel["b"] as NoInterfaceStartableComponent;
![](/Images/OutliningIndicators/InBlock.gif)
![](/Images/OutliningIndicators/InBlock.gif)
Assert.IsNotNull(component);
![](/Images/OutliningIndicators/InBlock.gif)
Assert.IsTrue( component.Started );
![](/Images/OutliningIndicators/InBlock.gif)
Assert.IsFalse( component.Stopped );
![](/Images/OutliningIndicators/InBlock.gif)
kernel.ReleaseComponent(component);
![](/Images/OutliningIndicators/InBlock.gif)
Assert.IsTrue( component.Stopped );
![](/Images/OutliningIndicators/InBlock.gif)
}
对于IKrnel大家可以自行修改为Castle.Windsor,这样也不失为一种使用Startable Facility的方法。
下篇:Castle IOC容器实践之Startable Facility(二)
参考资料
Castle的官方网站http://www.castleproject.org