Inside ObjectBuilder Part 4

发布时间:2016-12-6 20:06:17 编辑:www.fx114.net 分享查询网我要评论
本篇文章主要介绍了"Inside ObjectBuilder Part 4",主要涉及到Inside ObjectBuilder Part 4方面的内容,对于Inside ObjectBuilder Part 4感兴趣的同学可以参考一下。

ObjectBuilderApplicationBlock文/黄忠成2006/9/21 八、ObjectBuilder实务 8-1、ObjectBuilderWithConfiguration截至目前为止,本文一直以程序方式来配置ObjectBuidler建立对象所需的各种对象,但在实务上,这些动作应该是交由配置文件来负责,这样才能在不重新编译应用程序的情况下,改变其行为或增加其功能。很幸运的,Microsoft于ObjectBuilder的范例中提供了一个途径来达到此目的,该范例定义了一个.xsd文件,其内定义了ConstructorInjection、SetterInjection、Singleton、TypeMapping所需要的schema,当然!这个xsd中也定义了Strategy的schema,允许设计者通过配置文件来添加对象建立时所需使用的Strategys。 ConsturctorInjectionWithConfiguration我将Microsoft所提供可配置ObjectBuidler的范例中关于处理配置文件时的.xsd及相关文件提取出来,并添加MethodInjection时所需要的schema及程序代码,放置于本文的范例程序档中,当读者们需要使用配置文件这个功能时,可以将Config目录中的ObjectBuilderXmlConfig.xsd、ObjectBuilderXmlConfig.xsx、ObjectBuilderXmlConfig.cs、ObjectBuilderXmlConfig.Generate.cs等文件复制到项目目录中,并将ObjectBuilderXmlConfig.xsd、ObjectBuilderXmlConfig.Generate.cs加入到项目中,完成后再将ObjectBuilderXmlConfig.xsd设置成EmbeddedResource,如图10所示。图10接着将修改ObjectBuilderXmlConfig.cs中关于由Resource中取得.xsd内容的程序代码,修正namespace为项目的默认namespace即可。程序44 privatestaticObjectBuilderXmlConfigParseXmlConfiguration(stringconfig) { XmlSerializerser=newXmlSerializer(typeof(ObjectBuilderXmlConfig)); StringReaderstringReader=newStringReader(config); XmlSchemaschema= XmlSchema.Read( Assembly.GetExecutingAssembly().GetManifestResourceStream( "OB_CSConfigurationTest.ObjectBuilderXmlConfig.xsd"),null); XmlReaderSettingssettings=newXmlReaderSettings(); settings.ValidationType=ValidationType.Schema; settings.Schemas.Add(schema); XmlReaderreader=XmlReader.Create(stringReader,settings); ObjectBuilderXmlConfigconfigData=(ObjectBuilderXmlConfig)ser.Deserialize(reader); returnconfigData; }  要使用配置文件来完成ConstructorInjection,我们必须在项目中新增一个xml文件,内容如下所示。  object-builder-configxmlns="pag-object-builder"> build-rules> build-rule type="OB_ConfigurationTest.InputAccept,OB_CSConfigurationTest"mode="Instance"> constructor-params> ref-param type="OB_ConfigurationTest.PromptDataProcessor,OB_CSConfigurationTest"/> constructor-params> build-rule> build-rules> object-builder-config>  在ObjectBuilderXmlConfig.xsd定义中,build-rules代表着此BuilderContext中所有的对象建立规则,每个build-rule对应着一个“类型/id”,类型格式为,id部份则可通过添加name这个attribute来设置,未指定时就以null为默认值,如下。  build-rule type="OB_ConfigurationTest.InputAccept,OB_CSConfigurationTest" name=”id1”mode="Instance">  每个build-rule可以拥有一个constructor-params区段,设计者可以在这个区段中添加value-param或是ref-param定义,前者是直接设置该参数的值,后者是通过reference方式来设值,本例中是将InputAccept建构子的第一个参数值指定为PromptDataProcessor。程序45是使用这个配置文件的程序列表。 程序45 usingSystem; usingSystem.Collections.Generic; usingSystem.Text; usingSystem.IO; usingSystem.Configuration; usingMicrosoft.Practices.ObjectBuilder; usingMicrosoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder; usingMicrosoft.Practices.EnterpriseLibrary.Common.Configuration;   namespaceOB_ConfigurationTest { classProgram { staticvoidMain(string[]args) { using(FileStreamfs=newFileStream("XmlFile1.xml",FileMode.Open,FileAccess.Read)) { using(StreamReadersr=newStreamReader(fs)) { Builderbuilder=newBuilder(ObjectBuilderXmlConfig.FromXml(sr.ReadToEnd())); InputAcceptaccept=builder.BuildUpInputAccept>(newLocator(),null,null); accept.Execute(); Console.Read(); } } } }   publicclassInputAccept { privateIDataProcessor_dataProcessor;   publicvoidExecute() { Console.Write("PleaseInputsomewords:"); stringinput=Console.ReadLine(); input=_dataProcessor.ProcessData(input); Console.WriteLine(input); }   publicInputAccept([Dependency(Name="dataProcessor")]IDataProcessordataProcessor) { _dataProcessor=dataProcessor; } }   publicinterfaceIDataProcessor { stringProcessData(stringinput); }   publicclassDummyDataProcessor:IDataProcessor {   #regionIDataProcessorMembers   publicstringProcessData(stringinput) { returninput; }   #endregion }   publicclassPromptDataProcessor:IDataProcessor { #regionIDataProcessorMembers   publicstringProcessData(stringinput) { return"yourinputis:"+input; }   #endregion } }  SetterInjectionWithConfiguration 同样的,我们也可以通过配置文件来完成SetterInjection,此范例所使用的配置文件如下。  object-builder-configxmlns="pag-object-builder"> build-rules> build-rule type="OB_CSPropertyInjectionTest.InputAccept,OB_CSPropertyInjectionTest"mode="Instance"> propertyname="DataProcessor"> ref-param type="OB_CSPropertyInjectionTest.PromptDataProcessor,OB_CSPropertyInjectionTest"/> property> build-rule> build-rules> object-builder-config>  设计者必须将要设置的属性定义放置于build-rule区段中的property,property有一个nameattribute,代表着欲设置属性的名称,如要设置一个以上的属性,只需添加多个property区段即可,程序46是使用此配置文件的程序代码。 程序46 usingSystem; usingSystem.Collections.Generic; usingSystem.Text; usingSystem.IO; usingSystem.Configuration; usingMicrosoft.Practices.ObjectBuilder; usingMicrosoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder; usingMicrosoft.Practices.EnterpriseLibrary.Common.Configuration;   namespaceOB_CSPropertyInjectionTest { classProgram { staticvoidMain(string[]args) { using(FileStreamfs=newFileStream("XmlFile1.xml",FileMode.Open,FileAccess.Read)) { using(StreamReadersr=newStreamReader(fs)) { Builderbuilder=newBuilder(ObjectBuilderXmlConfig.FromXml(sr.ReadToEnd())); InputAcceptaccept=builder.BuildUpInputAccept>(newLocator(),null,null); accept.Execute(); Console.Read(); } } } }   publicclassInputAccept { privateIDataProcessor_dataProcessor;   [Dependency(Name="DataProcessor")] publicIDataProcessorDataProcessor { get { return_dataProcessor; } set { _dataProcessor=value; } }   publicvoidExecute() { Console.Write("PleaseInputsomewords:"); stringinput=Console.ReadLine(); input=_dataProcessor.ProcessData(input); Console.WriteLine(input); } }   publicinterfaceIDataProcessor { stringProcessData(stringinput); }   publicclassDummyDataProcessor:IDataProcessor {   #regionIDataProcessorMembers   publicstringProcessData(stringinput) { returninput; }   #endregion }   publicclassPromptDataProcessor:IDataProcessor { #regionIDataProcessorMembers   publicstringProcessData(stringinput) { return"yourinputis:"+input; }   #endregion } }  MethodInjectionWithConfiguration Microsoft所提供的配置文件机制并未定义MethodInjection的功能,我将其稍微修改来支援此功能,下面是MethodInjection时所用的配置文件。  object-builder-configxmlns="pag-object-builder"> build-rules> build-rule type="OB_CSMethodInjectionTest.InputAccept,OB_CSMethodInjectionTest"mode="Instance"> methodname="SetDataProcessor"> ref-param type="OB_CSMethodInjectionTest.PromptDataProcessor,OB_CSMethodInjectionTest"/> method> build-rule> build-rules> object-builder-config>  用法与property大致相同,程序47是程序代码列表。 程序47 usingSystem; usingSystem.Collections.Generic; usingSystem.Text; usingSystem.IO; usingMicrosoft.Practices.ObjectBuilder;   namespaceOB_CSMethodInjectionTest { classProgram { staticvoidMain(string[]args) { using(FileStreamfs=newFileStream("XmlFile1.xml",FileMode.Open,FileAccess.Read)) { using(StreamReadersr=newStreamReader(fs)) { Builderbuilder=newBuilder(ObjectBuilderXmlConfig.FromXml(sr.ReadToEnd())); InputAcceptaccept=builder.BuildUpInputAccept>(newLocator(),null,null); accept.Execute(); Console.Read(); } } } }   publicclassInputAccept { privateIDataProcessor_dataProcessor;   publicvoidSetDataProcessor([Dependency(Name="dataProcessor")]IDataProcessordataProcessor) { _dataProcessor=dataProcessor; }   publicvoidExecute() { Console.Write("PleaseInputsomewords:"); stringinput=Console.ReadLine(); input=_dataProcessor.ProcessData(input); Console.WriteLine(input); } }   publicinterfaceIDataProcessor { stringProcessData(stringinput); }   publicclassDummyDataProcessor:IDataProcessor {   #regionIDataProcessorMembers   publicstringProcessData(stringinput) { returninput; }   #endregion }   publicclassPromptDataProcessor:IDataProcessor { #regionIDataProcessorMembers   publicstringProcessData(stringinput) { return"yourinputis:"+input; }   #endregion } }  SingletonWithConfiguration 通过配置文件,也可以定义那个“类型/id”的对象是使用Singleton模式,如下所示。  build-ruletype="OB_CSMethodInjectionTest.PromptDataProcessor,OB_CSMethodInjectionTest"mode="Singleton"/>  TypeMappingWithConfiguration 我们也可以在配置文件中定义TypeMapping,如下所示。  build-rule type="OB_CSMethodInjectionTest.IDataProcessor,OB_CSMethodInjectionTest"mode="Instance"> mapped-type type="OB_CSMethodInjectionTest.PromptDataProcessor,OB_CSMethodInjectionTest"/> build-rule>  CustomizeStrategys 通过配置文件,也可以定义建立对象时所需要的Strategys,如下所示。  object-builder-configxmlns="pag-object-builder"> strategiesinclude-default="false"> strategy type="Microsoft.Practices.ObjectBuilder.TypeMappingStrategy,Microsoft.Practices.ObjectBuilder"/> strategy type="Microsoft.Practices.ObjectBuilder.CreationStrategy,Microsoft.Practices.ObjectBuilder"/> strategy type="Microsoft.Practices.ObjectBuilder.MethodExecutionStrategy,Microsoft.Practices.ObjectBuilder"/> ....................... object-builder-config>  include-default属性决定是否包含Builder对象所内建的Strategys。 九、后记ObjectBuilder是一个相当不错的DependencyInjection实作体,虽然相对于Spring、Avalon,ObjectBuilder并不是相当的完整,例如没有完整的配置文件驱动特色,但她所具备的高度延展性,可以让我们轻易的达到这个需求,且日后相信ObjectBuilder也会内建这些功能的。Trackback: http://tb.blog.csdn.net/TrackBack.aspx?PostId=1282167

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