Develop Reference

Cannot get log4net to write a log for a browser helper object (BHO) dll

I'm at my wits end, is it even possible to use log4net with an internet explorer browser helper object (BHO). I've tried just about everything I can find on the web and still no logfile.
My configuration is a separate log4net.config file and a bho that is designed to secure the browser for test takers. The log4net.config file is being picked up by the app and seems to be working, even to the point of an 'IsDebugEnabled' query. It seems to execute the write but nothing results.
My log4net.config
enter code here
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<log4net>
<appender name="FileAppender" type="log4net.Appender.FileAppender">
<file value="c:\Logs\lockdown.txt" />
<appendToFile value="true" />
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<!--<filter type="log4net.Filter.LevelRangeFilter">
<levelMin value="DEBUG" />
<levelMax value="FATAL" />
</filter>-->
<layout type="log4net.Layout.PatternLayout">
<param name="ConversionPattern" value="%-5p %d %-22.22c{1} %-25.25M - %m%n" />
</layout>
</appender>
<root>
<level value="ALL"/>
<appender-ref ref="FileAppender" />
</root>
</log4net>
</configuration>
public BHO()
{
LoadLogging();
_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
if (_log.IsDebugEnabled)
_log.Debug("************** Browser session started *************");
}
public void LoadLogging()
{
Debugger.Launch();
if (!log4net.LogManager.GetRepository().Configured)
{
var codeBase = Assembly.GetExecutingAssembly().CodeBase;
var uri = new UriBuilder(codeBase);
var pathDataString = Uri.UnescapeDataString(uri.Path);
var path = Path.GetDirectoryName(pathDataString);
var configFile = new FileInfo(path + "\\log4net.config");
if (!configFile.Exists)
{
throw new FileLoadException($"The configuration file {configFile} does not exist.");
}
log4net.Config.XmlConfigurator.Configure(configFile);
}
}
Any help would be appreciated ...

Whilst it may be possible (but unlikely) that BHOs are blocked from writing to a file, I doubt it would be blocked from writing to the debug window.
Try configuring log4net to write to the debug window:
<log4net>
<root>
<level value="ALL" />
<appender-ref ref="DebugAppender"/>
</root>
<appender name="DebugAppender" type="log4net.Appender.DebugAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date{dd.MM.yyyy HH:mm:ss.ffff} [%thread] %level %logger%exception - %message%newline" />
</layout>
</appender>
</log4net>

log4net enabled, but not creating any files

I've been shown how to use log4net and got a config file to use. I lost this config file and now I cant get it to work. For some reason the guy who configured it could not get it to work while having the configuration info in app.config so he placed it in log4net.config in the output folder.
He then called this when the program started up:
var logConfig = Path.Combine(Path.GetDirectoryName(typeof(App).Assembly.Location), "log4net.config");
var configStream = new FileInfo(logConfig);
log4net.Config.XmlConfigurator.Configure(configStream);
And it worked flawlessly.
Now I got it to work perfectly in a new console project. However allmost all of my projects are addons to another application so my project types are class libraries loaded by this other application (called Revit).
Anyway, so I know that I can log, but just cant get it to work...
This is log4net.config that I use:
<?xml version="1.0" encoding="utf-8" ?>
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
<file value="logs\" />
<datePattern value="dd.MM.yyyy'.log'" />
<staticLogFileName value="false" />
<appendToFile value="true" />
<rollingStyle value="Composite" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="5MB" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
<root>
<level value="ALL" />
<appender-ref ref="RollingFileAppender"/>
</root>
</log4net>
Each class that I want to log stuff from declares the an ILog instance on the class level.
Like this:
static private ILog _logger = LogManager.GetLogger(typeof(Program));
The ILog instance reports that all logging is enabled (debug and so on), but there are no files created.
Do I need to do anything else?
Im going nuts here!
Thanks for any help!

It seems you tried a few different ways to configure log4net. If one fails, the best option is to enable log4net debugging to see if your logger is working/crashed. In your app.config:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="log4net.Internal.Debug" value="true"/>
</appSettings>
...
<system.diagnostics>
<trace autoflush="true">
<listeners>
<add
name="textWriterTraceListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="C:\tmp\log4net.txt" />
</listeners>
</trace>
</system.diagnostics>
</configuration>
Log4net FAQ

In App.config file you should add this code in order to register the log4net section handler and the log will be generated
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
......
</configuration>
or Check if your AssemblyInfo.cs file has this code :
[assembly: log4net.Config.XmlConfigurator(ConfigFile = "Log4Net.config", Watch = true)]

Not able to get log4net working to write to file

I am using sharpdevelop to create a console application in C#. I have added in the reference for log4net and I added my logging statements while I was writing the code but I never looked at the log file. Now I am done with the code I need to get the log file working. My program runs fine, even the logging statements, but I can't find the log file.
I have tried to cobble together a couple of examples on getting log4net working. I have the lines to read from the configuration and then to instantiate the object, these are the first lines in my program to run:
log4net.Config.XmlConfigurator.Configure();
ILog datalogger = LogManager.GetLogger("myLog"); //initiate the data logger
Then in various places throughout the code I have this:
datalogger.Info(DateTime.Now.ToString() + ": using file: " + ProDirectory.ToString() + #"\" + myProFile.ToString());
I have also put the following in my app.config file:
<appender name="myLogAppender" type="log4net.Appender.RollingFileAppender" >
<file value="myLog.log" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level - %message%n" />
</layout>
</appender>
<logger name="myLog">
<level value="All"></level>
<appender-ref ref="myLogAppender" />
</logger>
No matter what I do, I can't see the log file being produced. I have changed the directory and even paused the program to see if I could find a handle open to the log file. Each time I come up empty. Not sure what I could be doing wrong.

not sure if this will help. I also had hard times making log4net work in different scenarios.
I use log4net root xml node to specify the appender. hope it will help.
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="log.txt" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="250KB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
<root>
<level value="DEBUG" />
<appender-ref ref="RollingFileAppender" />
</root>
UPDATE
You might also want to check Visual Studio output log. First setup the output log to log "ALL" (somewhere in VS settings). Then you should see exact error message of log4net in the output window of Visual Studio.

Whenever I have had issues with log4net creating the log file, it usually wound up being a file / directory permissions issue.
Change your <file value="log.txt" /> to something that you know will be accessible by the current user / process running devhost.
For example: <file value="%USERPROFILE%\Documents\log.txt" /> will create a log file in the user's My Documents folder. This is a folder that the user has permissions to write data to, and shouldn't give you any troubles with.
For more information on special folder values, see this link.

Looks like I just had to clean up my XML a little, after I did the log file is working fine:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections> <!-- Level 1 -->
<section name="log4net"
type="log4net.Config.Log4NetConfigurationSectionHandler,
log4net"/> <!-- Level 2 -->
</configSections>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
</startup>
<log4net>
<appender name="myLogAppender" type="log4net.Appender.RollingFileAppender" >
<file value="myLog.log" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level - %message%n" />
</layout>
</appender>
<logger name="myLog">
<level value="All"></level>
<appender-ref ref="myLogAppender" />
</logger>
</log4net>
</configuration>

Application crashes at modifying my App.config for Log4net

This is my first time ever using Log4Net so I'm sure I'm doing something really dumb.
In App.config, inside the <configuration> tag, I have the following:
<log4net>
<appender name="LogFileAppender" type="log4net.Appender.FileAppender">
<param name="File" value="log-file.txt" />
<param name="AppendToFile" value="true" />
<layout type="log4net.Layout.PatternLayout">
<param name="Header" value="[Header]\r\n" />
<param name="Footer" value="[Footer]\r\n" />
<param name="ConversionPattern" value="%d [%t] %-5p %c [%x] <%X{auth}> - %m%n" />
</layout>
</appender>
<root>
<level value="WARN" />
<appender-ref ref="LogFileAppender" />
</root>
</log4net>
In my Program.cs file I catch a ConfigurationException:
Message: Configuration system failed to initialize
InnerException: Unrecognized configuration section log4net.
But I copy-pasted the configuration code straight out of the .NET example they provide on their website. I read over their documentation but it's pretty confusing for someone who has never used any sort of logging framework before. I also found a few tutorials on CodeProject that hold your hand better but can't piece out what I've done wrong. I tried putting the <root> element before the <appender> element and that gives me the same ConfigException. And yes I've added a reference to the DLL to the project.

Sounds like you just forgot to include the configSection entry for log4net:
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
</configSections>
<!-- other configurations, such as appSettings and whatnot -->
<log4net>
<!-- log4net configuration that you already have -->
</log4net>
</configuration>
In order to use the log4net config node the system needs to be told how to interpret that node, which is handled in the log4net.Config.Log4NetConfigurationSectionHandler class.

log4net fails to log

So for some reason our logger has stopped logging and I am at a complete loss as to why.
What I'm using in my project is the following:
The log4net configuration:
<?xml version="1.0" encoding="utf-8"?>
<log4net>
<root>
<level value="DEBUG" />
<appender-ref ref="UdpAppender" />
<appender-ref ref="RollingFile" />
</root>
<appender name="UdpAppender" type="log4net.Appender.UdpAppender">
<remoteAddress value="127.0.0.1" />
<remotePort value="8180" />
<layout type="log4net.Layout.XmlLayoutSchemaLog4j">
<locationInfo value="true" />
</layout>
</appender>
<appender name="RollingFile" type="log4net.Appender.RollingFileAppender">
<file value="Logs/DA.RA.log"/>
<lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
<appendToFile value="true"/>
<maxSizeRollBackups value="10"/>
<maximumFileSize value="10MB"/>
<rollingStyle value="Size"/>
<staticLogFileName value="true"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%-5level %date %logger - %message%newline"/>
</layout>
</appender>
</log4net>
In my web.config I have the following line:
<section name="log4net"
type="log4net.Config.Log4NetConfigurationSectionHandler,log4net, Version=1.2.11.0, Culture=neutral, PublicKeyToken=a3d255455d3dcb36"
requirePermission="false"/>
In my global.asax I have the following line in the application_start method:
string filename = Server.MapPath( #"~\XML\log4net.xml" );
log4net.Config.XmlConfigurator.ConfigureAndWatch( new System.IO.FileInfo( filename ) );
and when I call the logger in any of my pages I use:
private static readonly ILog logger = LogManager.GetLogger(typeof(ReportParameters));
I have tried many different things I found online. These include:
adding the following line to the assembly in my project
[assembly: log4net.Config.XmlConfigurator(Watch=true)]
I tried:
[assembly: log4net.Config.XmlConfigurator()]
I've upgraded the version of my log4net.dll from 1.2.10.0 to 1.2.11.0.
I tried adding the log4net appenders to the web.config file instead of in it's own file, and I still get nothing out of the logging.

Try opening internal debugging of log4net and check or share the result:
Note: I made a sample app and used your same log4net.xml file and ConfigureAndWatch statement and it worked without a problem. I think you are having a filename path resolution problem or permission to write problem. Create log folder If you didn't.
You need to add to web.config
<appSettings>
<add key="log4net.Internal.Debug" value="true" />
</appSettings>
<system.diagnostics>
<trace autoflush="true">
<listeners>
<add
name="textWriterTraceListener"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="c:\\inetpub\\wwwroot\\log4net.txt" />
</listeners>
</trace>
</system.diagnostics>

Other than a possible file permission issue, I have found that when using
[assembly: log4net.Config.XmlConfigurator()]
in ASP.NET projects, that it would never actually do anything (I was using the debug string appender).
The solution for me was to start up log4net within the Application_Start even in global.asax.
protected void Application_Start()
{
log4net.Config.XmlConfigurator.Configure();
}

Replace this:
<section name="log4net"
type="log4net.Config.Log4NetConfigurationSectionHandler,log4net, Version=1.2.11.0, Culture=neutral, PublicKeyToken=a3d255455d3dcb36"
requirePermission="false"/>
For this:
<section name="log4net"
type="log4net.Config.Log4NetConfigurationSectionHandler,log4net"
requirePermission="false"/>
And instead of
log4net.Config.XmlConfigurator.ConfigureAndWatch()
Call
log4net.Config.XmlConfigurator.Configure();
Let me know if it works that way