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配置文件中的DTD实体

config entity .net

ZaDDaZ · 技术社区 · 15 年前

我试图在配置文件中使用实体定义来简化开发、qa、uat和生产版本之间的差异。以下是配置文件开头的示例:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE configuration [
    <!ENTITY MyStorageLocation "\\MyServer\MyStorageFolder">
    <!ENTITY MyDatabaseServer "devdb01">
]>
<configuration>
    <configSections>
    <section name="MyCustomSection" type="MyCustomSectionHandler,MyAssembly"/>
        ...
    </configSections>
<connectionStrings>
    <add name="MyConnectionString" providerName="System.Data.SqlClient" connectionString="Server=&MyDatabaseServer;;Database=MyDatabase;"/>
</connectionStrings>
    ...
<MyCustomSection>&MyStorageLocation;</MyCustomSection>
</configuration>

这似乎工作得很好,既然它是完全有效的XML,那么为什么不呢?只要我在一个自定义配置节中不使用这些实体中的任何一个,最后我将在该节上调用configurationmanager.getSection()。在连接字符串中使用“mydatabaseserver”实体不会导致任何问题。在提供的示例中,只要我不在myCustomSection元素中使用“myStorageLocation”实体,然后只在调用configurationManager.getSection()请求自定义节时遇到错误,一切都将正常工作。

我最好的猜测是,configurationmanager类正在获取元素的原始源并尝试将其加载为xml,而忽略整个xml文件的声明实体。有没有更好的方法来做到这一点,不重新编码自定义配置节,以支持对设置的引用,而不是许多绝对设置?

我收到的错误是:

2009-01-27 14:00:53,474 [11936] ERROR MyCustomWindowsService [(null)] - Errors starting service -- shutting down
System.Configuration.ConfigurationErrorsException: Reference to undeclared entity 'MyStorageLocation'. Line 183, position 19. (D:\...\MyCustomWindowsService.exe.config line 183) ---> System.Xml.XmlException: Reference to undeclared entity 'MyStorageLocation'. Line 183, position 19.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.HandleGeneralEntityReference(String name, Boolean isInAttributeValue, Boolean pushFakeEntityIfNullResolver, Int32 entityStartLinePos)
   at System.Xml.XmlTextReaderImpl.ResolveEntity()
   at System.Xml.XmlTextReader.ResolveEntity()
   at System.Xml.XmlLoader.LoadEntityReferenceNode(Boolean direct)
   at System.Xml.XmlLoader.LoadNode(Boolean skipOverWhitespace)
   at System.Xml.XmlLoader.LoadDocSequence(XmlDocument parentDoc)
   at System.Xml.XmlLoader.Load(XmlDocument doc, XmlReader reader, Boolean preserveWhitespace)
   at System.Xml.XmlDocument.Load(XmlReader reader)
   at System.Configuration.ErrorInfoXmlDocument.LoadFromConfigXmlReader(ConfigXmlReader reader)
   at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory.CreateSectionImpl(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentConfig, ConfigXmlReader reader)
   at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory.CreateSectionWithRestrictedPermissions(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentConfig, ConfigXmlReader reader)
   at System.Configuration.RuntimeConfigurationRecord.CreateSection(Boolean inputIsTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentConfig, ConfigXmlReader reader)
   at System.Configuration.BaseConfigurationRecord.CallCreateSection(Boolean inputIsTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentConfig, ConfigXmlReader reader, String filename, Int32 line)
   --- End of inner exception stack trace ---
   at System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult)
   at System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object& result, Object& resultRuntimeObject)
   at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
   at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
   at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject)
   at System.Configuration.BaseConfigurationRecord.GetSection(String configKey, Boolean getLkg, Boolean checkPermission)
   at System.Configuration.BaseConfigurationRecord.GetSection(String configKey)
   at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName)
   at System.Configuration.ConfigurationManager.GetSection(String sectionName)
   at MyCustomWindowsService.Monitor() in D:\...\MyCustomWindowsService.cs:line 207
   at MyCustomWindowsService.Start() in D:\...\MyCustomWindowsService.cs:line 178

在配置管理器的内部深处…

1 回复 | 直到 14 年前

kmcorbett 15 年前

也许您的XML处理器忽略了!实体声明,因为它们包含在否则为空的DTD中。

您有可以用来验证此文档的DTD吗?如果缺少DTD或模式,就不能说文档是有效的。尝试通过在线XML验证服务运行它,如URL上的服务: http://www.validome.org/xml/validate/

这是你的文件的修订版,上面有我加上去的DTD。看看这是否有用。

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE configuration [
    <!ELEMENT configuration (configSections+, connectionStrings+, MyCustomSection)>

    <!ELEMENT configSections (section+)>

    <!ELEMENT section EMPTY>
    <!ATTLIST section name CDATA #REQUIRED>
    <!ATTLIST section type CDATA #REQUIRED>

    <!ELEMENT connectionStrings (add+)>

    <!ELEMENT add EMPTY>
    <!ATTLIST add name CDATA #REQUIRED>
    <!ATTLIST add providerName CDATA #REQUIRED>
    <!ATTLIST add connectionString CDATA #REQUIRED>

    <!ELEMENT MyCustomSection (#PCDATA)>

    <!ENTITY MyStorageLocation "\\MyServer\MyStorageFolder">
    <!ENTITY MyDatabaseServer "devdb01">
]>
<configuration>
  <configSections>
    <section name="MyCustomSection" type="MyCustomSectionHandler,MyAssembly"/>
  </configSections>
  <connectionStrings>
    <add name="MyConnectionString" providerName="System.Data.SqlClient" connectionString="Server=&MyDatabaseServer;;Database=MyDatabase;"/>
  </connectionStrings>
  <MyCustomSection>&MyStorageLocation;</MyCustomSection>
</configuration>