Unable to resolve service for type 'System.Collections.Generic.List`1[Microsoft.Extensions.Logging.ILoggerProvider]'

Hi there!

First of all, thank you for developing this library. I’ve used it in many projects and it’s really convenient not having to register all services by hand.

In the current project, I am batteling a problem. I have a class which extends List<T>:

  public class PagedList<T> : List<T>
    {
        public int CurrentPage { get; }
        public int TotalPages { get; }
     // ...

Now whenever this class exists, I think what happens is, scrutor tries to register List<T> in the DI container. This is not my intention and it fails obviously. Here is the beginning of the (long) stacktrace:

Unhandled exception. System.AggregateException: Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: Microsoft.Extensions.Hosting.IHostApplicationLifetime Lifetime: Singleton ImplementationType: Microsoft.Extensions.Hosting.Internal.ApplicationLifetime': Unable to resolve service for type 'System.Collections.Generic.List`1[Microsoft.Extensions.Logging.ILoggerProvider]' while attempting to activate 'icpms.Shared.Pagination.PagedList`1[Microsoft.Extensions.Logging.ILoggerProvider]'.) (Error while validating the service descriptor 'ServiceType: Microsoft.Extensions.Hosting.IHostLifetime Lifetime: Singleton ImplementationType: Microsoft.Extensions.Hosting.Internal.ConsoleLifetime': Unable to resolve service for type 'System.Collections.Generic.List`1[Microsoft.Extensions.Options.IConfigureOptions`1[Microsoft.Extensions.Hosting.ConsoleLifetimeOptions]]' while attempting to activate 'icpms.Shared.Pagination.PagedList`1[Microsoft.Extensions.Options.IConfigureOptions`1[Microsoft.Extensions.Hosting.ConsoleLifetimeOptions]]'.) (Error while validating the service descriptor 'ServiceType: Microsoft.Extensions.Hosting.IHost Lifetime: Singleton ImplementationType: Microsoft.Extensions.Hosting.Internal.Host': Unable to resolve service for type 'System.Collections.Generic.List`1[Microsoft.Extensions.Logging.ILoggerProvider]' while attempting to activate 'icpms.Shared.Pagination.PagedList`1[Microsoft.Extensions.Logging.ILoggerProvider]'.) (Error while validating the service descriptor 'ServiceType: Microsoft.Extensions.Logging.ILoggerFactory Lifetime: Singleton ImplementationType: Microsoft.Extensions.Logging.LoggerFactory': Unable to resolve service for type 'System.Collections.Generic.List`1[Microsoft.Extensions.Logging.ILoggerProvider]' while attempting to activate 'icpms.Shared.Pagination.PagedList`1[Microsoft.Extensions.Logging.ILoggerProvider]'.) 
...

I am probably missing something obvoious here. How can I tell Scrutor to ignore PagedList<T> within my project?

[khellang]

First, I wouldn’t recommend using AddClasses without any filter. It will definitely register way more than you need, which will cost both in terms of CPU and memory. Especially when using publicOnly: false.

I’m not at a computer right now, so it’s a bit hard to write the code, but essentially you want to enumerate through the service collection and check if the ServiceType is assignable to IEnumerable.

[khellang]

Hi @riscie!

I’m not sure what your setup looks like, but it looks like it’s registering a bit too much, yes. We’ve talked about adding additional filters, like IEnumerable<T>, but because it’s a breaking change, we haven’t done it yet. See https://github.com/khellang/Scrutor/issues/65.

I suggest you supply a filter when calling AddClasses that will register only the types you’re after for now.