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Posts Tagged ‘logging’

log4net with Compact Framework

October 13th, 2009 robber.baron 1 comment

My favorite logging library log4net work not only on desktop and web applications but can be used on mobile devices with the compact framework.

Granted not all of the Appenders make sense within the compact framework. Since mobile devices have neither a system log nor a console it doesn’t make much sense to have these appenders. For a complete list of supported frameworks and appenders see here.

Applications written in the compact framework don’t have app.config files.  This presents an issue when attempting to create an ILog.  Here is my work around.

First create an XML that will be copied to source on deployment.  Here is an example:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <log4net debug="false">
    <appender name="logger" type="log4net.Appender.RollingFileAppender">
      <file value="\SD Card\Assessment\DamageAssessmentLog.txt" />
      <appendToFile value="true" />
      <maxSizeRollBackups value="2" />
      <maximumFileSize value="1048576" />
      <rollingStyle value="Composite" />
      <staticLogFileName value="false" />
      <layout type="log4net.Layout.PatternLayout">
        <header value="[Header]&#13;&#10;"/>
        <footer value="[Footer]&#13;&#10;"/>
        <conversionPattern value="%newline Date: %date ,Application: %a ,Logger: %logger ,Thread: [%thread] ,Level: %level %newline Message: %message%newline Exception: %exception%newline" />
      </layout>
      </appender>
      <!-- Setup the root category, add the appenders and set the default level -->
      <root>
        <level value="DEBUG" />
        <appender-ref ref="logger" />
      </root>
    </log4net>
</configuration>

This should all be familiar so far. Basically whatever was going to go into app.config will now be in this file.

Then within your application’s startup you need to explicitly point log4net to that configuration file.

Shared Sub Main()
        Try
            Dim logconfig = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase), "logging.config")
 
            log4net.Config.XmlConfigurator.Configure(New FileInfo(logconfig))
 
            Dim logger As ILog = log4net.LogManager.GetLogger("logger")
 
            Using map As formMap = New formMap()
                logger.Debug("Staring application")
                map.ShowDialog()
                logger.Debug("Application closed")
            End Using
            AssessmentConnector.Instance.CloseConnection()
        Catch ex As Exception
            MessageBox.Show(ex.ToString)
        Finally
            log4net.LogManager.Shutdown()
        End Try
    End Sub

Here you can see that I get the application’s executing path and append the xml file’s name. Then I call the log4net.Config.XmlConfigurator to initialize the logging service from the provided xml file.

Note: Due to limitations of the compact framework it is important that you call log4net.LogManager.Shutdown() to explicitly close your log files. Otherwise you’ll end up with a hanging process and open log files.

Categories: Compact Framework, Programming Tags: , ,