Log4Net，如何向我的日志添加自定义字段

1) Modify the command text: INSERT INTO Log4Net ([Date],[Thread],[Level],[Logger],[Message],[Exception],[MyColumn]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception, @CustomColumn)

2) Add the parameter definition for the custom column:

<parameter>
<parameterName value="@CustomColumn"/>
<dbType value="String" />
<size value="255" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%property{CustomColumn}" />
</layout>
</parameter>

3) Then use one of log4net’s contexts to transfer values to the parameter:

// thread properties...
log4net.LogicalThreadContext.Properties["CustomColumn"] = "Custom value";
log.Info("Message");


// ...or global properties
log4net.GlobalContext.Properties["CustomColumn"] = "Custom value";

Here is a working version with some personalized preferences. I added a custom column for storing a generated exception code.

1) Add your custom column(exceptionCode here) to Log4net config:

<commandText value="INSERT INTO Log([Date],[Thread],[Level],[Logger],[Message],[Exception],[ExceptionCode])
VALUES (@log_date, @thread, @log_level, @logger, @message, @exception,@exceptionCode)" />


<parameter>
<parameterName value="@exceptionCode" />
<dbType value="String" />
<size value="11" />
<layout type="Common.Utils.LogHelper.Log4NetExtentedLoggingPatternLayout">
<conversionPattern value="%exceptionCode{Code}" />
</layout>
</parameter>

2) Log4NetExtentedLoggingCustomParameters.cs

namespace Common.Utils.LogHelper
{
public class Log4NetExtentedLoggingCustomParameters
{
public string ExceptionCode { get; set; }


public string Message { get; set; }


public override string ToString()
{
return Message;
}
}
}

3) Log4NetExtentedLoggingPatternConverter.cs

namespace Common.Utils.LogHelper
{
public class Log4NetExtentedLoggingPatternConverter : PatternConverter
{
protected override void Convert(TextWriter writer, object state)
{
if (state == null)
{
writer.Write(SystemInfo.NullText);
return;
}


var loggingEvent = state as LoggingEvent;
var messageObj = loggingEvent.MessageObject as Log4NetExtentedLoggingCustomParameters;


if (messageObj == null)
{
writer.Write(SystemInfo.NullText);
}
else
{
switch (this.Option.ToLower()) //this.Option = "Code"
{
case "code": //config conversionPattern parameter -> %exceptionCode{Code}
writer.Write(messageObj.ExceptionCode);
break;
default:
writer.Write(SystemInfo.NullText);
break;
}
}
}
}
}

4) Log4NetExtentedLoggingPatternLayout.cs

namespace Common.Utils.LogHelper
{
public class Log4NetExtentedLoggingPatternLayout : PatternLayout
{
public Log4NetExtentedLoggingPatternLayout()
{
var customConverter = new log4net.Util.ConverterInfo()
{
Name = "exceptionCode",
Type = typeof(Log4NetExtentedLoggingPatternConverter)
};


AddConverter(customConverter);
}
}
}

5) Logger.cs // Enjoy your logger with new column! :)

namespace Common.Utils.LogHelper
{
public class Logger
{
static ILog Logger = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);


public static string LogError(string message, Exception exception = null)
{
var logWithErrCode = GetLogWithErrorCode(message);
Logger.Error(logWithErrCode, exception);
return logWithErrCode.ExceptionCode;
}


private static Log4NetExtentedLoggingCustomParameters GetLogWithErrorCode(string message)
{
var logWithErrCode = new Log4NetExtentedLoggingCustomParameters();
logWithErrCode.ExceptionCode = GenerateErrorCode(); //this method is absent for simplicity. Use your own implementation
logWithErrCode.Message = message;
return logWithErrCode;
}
}
}

references:

http://blog.stvjam.es/2014/01/logging-custom-objects-and-fields-with

Three types of logging context available in Log4Net.

1. Log4Net.GlobalContext :- This context shared across all application threads and domains.If two threads set the same property on GlobalContext, One Value will override the other.

2. Log4Net.ThreadContext :- This context scope limited to calling thread. Here two threads can set same property to different values without overriding to each other.

3. Log4Net.ThreadLogicalContext :- This context behaves similarly to the ThreadContext. if you're working with a custom thread pool algorithm or hosting the CLR, you may find some use for this one.

Add the following code to your program.cs file:

static void Main( string[] args )
{
log4net.Config.XmlConfigurator.Configure();
log4net.ThreadContext.Properties[ "myContext" ] = "Logging from Main";
Log.Info( "this is an info message" );
Console.ReadLine();
}

2) Add the parameter definition for the custom column:

  <log4net>
<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%logger (%property{myContext}) [%level]- %message%newline" />
</layout>
</appender>
</log4net>