问题
I extended AppenderSkeleton to create a custom appender called HTTPAppender, but something is up with the reference to it in the xml file. Log4Net is clearly unable to find my custom appender. Is there a way to reference it from the xml file to point to my project, or would I have to add my custom appender's source code to log4net's so it's packaged in log4net.dll?
I get the following error in the Immediate window when debugging:
log4net:ERROR XmlHierarchyConfigurator: Could not create Appender [HTTPAppender] of type [HTTPAppender.HTTPAppender,HTTPAppender]. Reported error follows. System.IO.FileNotFoundException: Could not load file or assembly 'HTTPAppender' or one of its dependencies. The system cannot find the file specified. File name: 'HTTPAppender' at System.RuntimeTypeHandle._GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, Boolean loadTypeFromPartialName) at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark) ...etc
Here's the log4net section of the xml file:
<log4net>
<appender name="HTTPAppender" type="HTTPAppender.HTTPAppender,HTTPAppender">
<evaluator type="log4net.Core.LevelEvaluator,log4net">
<threshold value="WARN"/>
</evaluator>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="#%level - %message" />
</layout>
</appender>
<root>
<level value="ALL" />
<appender-ref ref="HTTPAppender" />
</root>
<logger name="log4netErrorLog" >
<level value="DEBUG" />
<appender-ref ref="HTTPAppender" />
</logger>
</log4net>
回答1:
If you are using any non standard assemblies, put them in the application directory together with your assembly. If that doesn't help, try giving your assembly a strong name and using the full name in the log4net config file. you can also try putting it into GAC.
回答2:
i think this will help you
http://weblogs.asp.net/tgraham/archive/2007/05/02/loading-the-assembly-for-a-custom-log4net-appender.aspx
回答3:
I would assume that the assembly cannot be found. Is the name of the assembly indeed 'HTTPAppender' and is it in the same path as the calling assembly?
回答4:
I've had the same issue. If your custom appender project uses a certain log4net.dll, and your project that's going to use your custom appender uses a different log4net.dll, it will not be able to find it.
回答5:
I was also stuck in that issue finally I fixed it.
The solution is HTTPAppender class should have a Default contructor.
I am confident about that this error "Could not create Appender" is come because doesn't have default constructor
回答6:
I run into the same issue recently. I fixed it by adding the assembly name after the fully qualified name of the type with a comma in the type attribute. Please see below.
<log4net>
<appender name="LogFileAppender" type="TestHarness.Model.CustomRollingFileAppender, TestHarness.Model">
</log4net>
来源：https://stackoverflow.com/questions/2115037/log4net-error-on-loading-custom-appender