Qfyilyi

I am struggling with finding a way to register log4net ILog within IServiceCollection services (.NET Core 2.1).

log4net LogManager provides a method that takes a Type as parameter so that it can be used when logging events. Here is an example call:

var log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

However when registering it with services at Startup method, I can use factory resolver, but still the type will be always the same. See the following excerpt:

private void SetServices(IServiceCollection services)

{

    services.AddTransient(svc => CreateLog(MethodBase.GetCurrentMethod().DeclaringType)).;

}



protected ILog CreateLog(Type type)

{

    return LogManager.GetLogger(type);

}

I was expecting that svc (IServiceProvider) will expose some ways to get to the type being actually resolved but there doesn't seem to be anything.
Also using reflection won't help (IMO, but I could be wrong) because ILog is activated prior to calling the resolved type ctor.

But maybe there is any extension on either MS side or log4net that would help resolving a named logger as explained on the beginning?

This is all to avoid having static members of ILog in any class that uses logging facility and use dependency injection instead.

Thanks, Radek

The way to do it is to implement and then register your own strongly typed Logger class that derives from ILogger.

.Net Core allows from to register generic type interface implementation with no type specified. In this case it would be:

services.Add(ServiceDescriptor.Singleton(typeof(ILogger<>), typeof(MyLogging.Logger<>)));

This allows all classes that require logging to use constructor injection as follows:

class A

{

    public A(Ilogger<A> logger) {...}

}

Implementation of ILogger which a wrapper to log4net should be rather simple. Please let me know if you need an example.

Radek