Question

I want to inject a type-information to the log-call, like

public sealed class Logger
{
    private readonly log4net.ILog _logger;

    public Logger()
    {
        // somehow assing this._logger ... doesn't matter actually
    }

    public void Info<T>(string message)
    {
        if (!this._logger.IsInfoEnabled)
        {
            return;
        }

        var typeOfT = typeof (T);
        var typeName = typeOfT.FullName;

        // how to set a property here, only for this one single call
        // which i can reference in the config

        this._logger.Info(message);
    }
}

The comment makes it clear: at some point I’d like to inject the FullName of my generic-parameter only for this one specific call.

I am using log4net 1.2.11.0

Answer 1

Actually it’s pretty simple:

public class Foo : log4net.Core.LogImpl
{
    private static readonly Type DeclaringType = typeof (Foo);

    public Foo(log4net.Core.ILoggerWrapper loggerWrapper)
        : this(loggerWrapper.Logger) {}

    public Foo(log4net.Core.ILogger logger)
        : base(logger) {}

    protected LoggingEvent GetLoggingEvent<T>(Level level, string message, Exception exception = null)
    {
        var loggingEvent = new LoggingEvent(DeclaringType, this.Logger.Repository, this.Logger.Name, level, message, exception);
        loggingEvent.Properties["type"] = typeof (T).FullName;

        return loggingEvent;
    }

    public void Info<T>(string message)
    {
        if (!this.IsInfoEnabled)
        {
            return;
        }

        var loggingEvent = this.GetLoggingEvent<T>(Level.Info, message);

        this.Logger.Log(loggingEvent);
    }

    public void Info<T>(string message, params object[] args)
    {
        if (!this.IsInfoEnabled)
        {
            return;
        }

        message = string.Format(message, args);

        var loggingEvent = this.GetLoggingEvent<T>(Level.Info, message);

        this.Logger.Log(loggingEvent);
    }
}