如何在配置文件中注册自定义Log4Net对象呈现程序

我正在尝试使用自定义渲染器在log4net中记录一个对象。我的配置文件有以下行:

  <renderer renderingClass="LogLibrary.Log4NetObjRenderers.PdaLogObjRenderer" renderedClass="LogLibrary.TranferObjects.PdaLogObj" />

但是在加载配置文件时,我得到一个TypeLoadException,log4net内部调试给出了以下详细信息:

log4net:ERROR OptionConverter: Could not instantiate class [LogLibrary.Log4NetObjRenderers.PdaLogObjRenderer].
System.TypeLoadException: Could not load type [LogLibrary.Log4NetObjRenderers.PdaLogObjRenderer]. Tried assembly [log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=1b44e1d426115821] and all loaded assemblies
   at log4net.Util.SystemInfo.GetTypeFromString(Assembly relativeAssembly, String typeName, Boolean throwOnError, Boolean ignoreCase) in c:\work\svn_root\apache\log4net\tags\log4net-1.2.10-rc2\build\package\log4net-1.2.10\src\Util\SystemInfo.cs:line 671
   at log4net.Util.SystemInfo.GetTypeFromString(String typeName, Boolean throwOnError, Boolean ignoreCase) in c:\work\svn_root\apache\log4net\tags\log4net-1.2.10-rc2\build\package\log4net-1.2.10\src\Util\SystemInfo.cs:line 602
   at log4net.Util.OptionConverter.InstantiateByClassName(String className, Type superClass, Object defaultValue) in c:\work\svn_root\apache\log4net\tags\log4net-1.2.10-rc2\build\package\log4net-1.2.10\src\Util\OptionConverter.cs:line 477
log4net:ERROR XmlHierarchyConfigurator: Could not instantiate renderer [LogLibrary.Log4NetObjRenderers.PdaLogObjRenderer].

对象和呈现程序的命名空间是正确的。

有什么想法吗?

编辑:这就是我在Global.asax中设置log4net的方式

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
    // Fires when the application is started

    Dim logfile As String = "C:\Applications\LoggerWebService\Config\logConfig.xml"
    log4net.GlobalContext.Properties("Application") = My.Application.Info.ProductName
    log4net.GlobalContext.Properties("Version") = My.Application.Info.Version.ToString

    log4net.Config.XmlConfigurator.ConfigureAndWatch(New IO.FileInfo(logfile))

    Dim logger As log4net.ILog = log4net.LogManager.GetLogger(GetType(Global_asax))
    logger.Info("Started")

End Sub