How to access IServiceCollection and/or IServiceProvider outside of Startup class?

Question

I am using Microsoft.Extensions.DependencyInjection in .Net Farmework 4.6.2 class libraries. How to access IServiceCollection and/or IServiceProvider from outside the source code where they are instantiated, Main(), for instance? I could create a static class exposing this property in a separate class library and referenced it but I am wondering if there is any other better way of achieving this objective. .Net Framework has ServiceLocator.Current.GetInstance. Is there any similar thing in Microsoft.Extensions.DependencyInjection? Any advice and insight is appreciated.

Answer 1

Different from the IServiceProvider, the IServiceCollection can't be injected into a class constructor.

As many have already said, you should avoid using them directly. But if you really need to do so for the IServiceCollection, you can create a "Provider", such as:

    public interface IServiceCollectionProvider 
    {
        IServiceCollection ServiceCollection { get; }
    }

    public sealed class ServiceCollectionProvider: IServiceCollectionProvider
    {
        public ServiceCollectionProvider(IServiceCollection serviceCollection)
        {
            ServiceCollection = serviceCollection;
        }

        public IServiceCollection ServiceCollection { get; }
    }

Registering:

services.AddSingleton<IServiceCollectionProvider>(new ServiceCollectionProvider(services));

Using:

    public class YourController : Controller
    {
        private readonly IServiceProvider _provider;
        private readonly IServiceCollection _services;

        public YourController (IServiceProvider provider, IServiceCollectionProvider serviceCollectionProvider)
        {
            _provider = provider;
            _services = serviceCollectionProvider.ServiceCollection;
        }
    }