How To Do Logging with Caliburn.Micro

DebugLogger.cs

class DebugLogger : ILog
{
  #region Fields
  private readonly Type _type;
  #endregion
  
  #region Constructors
  public DebugLogger(Type type)
  {
    _type = type;
  }
  #endregion
  
  #region Helper Methods
  private string CreateLogMessage(string format, params object[] args)
  {
    return string.Format("[{0}] {1}", 
    DateTime.Now.ToString("o"),
    string.Format(format, args));
  }
  #endregion
  
  #region ILog Members
  public void Error(Exception exception)
  {
    Debug.WriteLine(CreateLogMessage(exception.ToString()), "ERROR");
  }
  
  public void Info(string format, params object[] args)
  {
    Debug.WriteLine(CreateLogMessage(format, args), "INFO");
  }
  
  public void Warn(string format, params object[] args)
  {
    Debug.WriteLine(CreateLogMessage(format, args), "WARN");
  }
  #endregion
}

ILog.cs

/// <summary>
// A logger.
// </summary>
public interface ILog
{
  /// <summary>
  /// Logs the message as info.
  /// </summary>
  /// <param name="format">A formatted message.</param>
  /// <param name="args">Parameters to be injected into the formatted message.</param>
  void Info(string format, params object[] args);

  /// <summary>
  /// Logs the message as a warning.
  /// </summary>
  /// <param name="format">A formatted message.</param>
  /// <param name="args">Parameters to be injected into the formatted message.</param>
  void Warn(string format, params object[] args);
 
  /// <summary>
  /// Logs the exception.
  /// </summary>
  /// <param name="exception">The exception.</param>
  void Error(Exception exception);
}

log4net_app.config

<configSections>
  <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>

<log4net>
  <appender name="TraceAppender" type="log4net.Appender.TraceAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level - %message%newline" />
    </layout>
  </appender>
  <appender name="OutputDebugStringAppender" type="log4net.Appender.OutputDebugStringAppender" >
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
  </appender>
  <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender" >
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger [%ndc] - %message%newline" />
    </layout>
  </appender>
  <root>
    <level value="DEBUG" />
    <appender-ref ref="TraceAppender" />
  </root>
</log4net>

Log4netLogger.cs

class Log4netLogger : ILog
{
  #region Fields
  private readonly log4net.ILog _innerLogger;
  #endregion
  
  #region Constructors
  public Log4netLogger(Type type)
  {
    _innerLogger = log4net.LogManager.GetLogger(type);
  }
  #endregion
 
  #region ILog Members
  public void Error(Exception exception)
  {
    _innerLogger.Error(exception.Message, exception);
  }
  public void Info(string format, params object[] args)
  {
    _innerLogger.InfoFormat(format, args);
  }
  public void Warn(string format, params object[] args)
  {
    _innerLogger.WarnFormat(format, args);
  }
  #endregion
}

LogManager.cs

/// <summary>
/// Used to manage logging.
/// </summary>
public static class LogManager
{
  static readonly ILog NullLogInstance = new NullLog();

  /// <summary>
  /// Creates an <see cref="ILog"/> for the provided type.
  /// </summary>
  public static Func<Type, ILog> GetLog = type => NullLogInstance;

  private class NullLog : ILog
  {
    public void Info(string format, params object[] args) { }
    public void Warn(string format, params object[] args) { }
    public void Error(Exception exception) { }
  }
}

MyBootStrapper.cs

public class MyBootStrapper : Bootstrapper<ShellViewModel>
{
  static MyBootStrapper()
  {
    LogManager.GetLog = type => new DebugLogger(type);
  }
}

nlog_app.config

<configSections>
  <section name="nlog" type="NLog.Config.ConfigSectionHandler, NLog"/>
</configSections>

<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <targets>
    <target name="tr" xsi:type="Trace"/>
  </targets>
  <rules>
    <logger name="*" writeTo="tr" />
  </rules>
</nlog>

NLogLogger.cs

class NLogLogger : ILog
{
  #region Fields
  private readonly NLog.Logger _innerLogger;
  #endregion
  
  #region Constructors
  public NLogLogger(Type type)
  {
    _innerLogger = NLog.LogManager.GetLogger(type.Name);
  }
  #endregion
  
  #region ILog Members
  public void Error(Exception exception)
  {
    _innerLogger.ErrorException(exception.Message, exception);
  }
  public void Info(string format, params object[] args)
  {
    _innerLogger.Info(format, args);
  }
  public void Warn(string format, params object[] args)
  {
    _innerLogger.Warn(format, args);
  }
  #endregion
}