How to Inject Log4Net ILog implementations using Unity 2.0

Question

Ultimately this has to do with setting up log4Net but generically the problem is not logging specific.

Generically what I am trying to figure out is how to do, in Microsoft Unity 2.0, something equivalent to what one gets with the Castle.Facilities.Logging.LoggingFacility. Namely the ability to declare a dependency on a logger and have the logger initialized with the Type of the object into which it is being injected.

In the spirit of a test is worth a thousand words, here is what I need:

class Logger_IOC_Tests {     //[Test]      public void Logger_should_be_initialized_with_the_type_of_the_object_that_is_using_it()     {         var container = new UnityContainer();         /* Configuration Magic probably involiving registering either              * a custom IDependencyResolverPolicy or BuilderStrategy             * goes here...             */         container.RegisterType<LoggerUser>(new ContainerControlledLifetimeManager());          var user = container.Resolve<LoggerUser>();          Assert.True(user.Logger.GetUserType() == user.GetType());     } }  interface ILogger {     Type GetUserType(); }  class Logger : ILogger {     private readonly Type _type;      public Logger(Type type)     {         _type = type;     }      public Type GetUserType()     {         return _type;     } }  class LoggerUser {     public readonly ILogger Logger;      public LoggerUser(ILogger logger)     {         Logger = logger;     } } 

Answer 1

I don't know if this what you are looking for, but I saw it a few months ago and was reminded of it when I saw your question. I have not used Unity, so I can't really compare what you have posted with what is at the link. Hopefully it will be useful to you:

http://davidkeaveny.blogspot.com/2011/03/unity-and-log4net.html

Answer 2

I've been trying to achieve the same result of being able to insert correctly configured ILog instances into a dependency using constructor injection with Unity.

In the end, I wrote my own "log4net" unity extension to do exactly this (in part inspired by a blog post that another answerer, Kenneth Baltrinic, wrote).

This allows you to register the extension once with Unity:

var container = new UnityContainer(); container.AddNewExtension<Log4NetExtension>(); 

and then have the correct ILog logger instance passed in:

public class MyClass {     private readonly ILog logger;      public MyClass(ILog logger)     {         this.logger = logger;     } } 

The extension can be found here:

https://github.com/roblevine/UnityLoggingExtensions

More info here: http://blog.roblevine.co.uk/net/using-log4net-with-unity/

EDIT this is now available as a NuGet package