I could not find an example showing how to use Microsoft.Extensions.DependencyInjection as IoC in OWIN Self-Hosted WebApi, as a result here is this blog post.

Let’s imagine that you have WebApi that you intend to Self-Host using OWIN. This is fairly easy to do. All you will need to do is to use Microsoft.Owin.Hosting.WebApp.Start method and then have a bit of configuration on IAppBuilder (check out ServiceHost.cs and WebApiStartup.cs in the gist below).

It becomes a bit more complicated when you want to use an IoC container, as OWIN’s implementation takes care of creating Controller instances. To use another container you will need to tell the configuration to use implementation of IDependencyResolver (see WebApiStartup.cs and DefaultDependencyResolver.cs). DefaultDependencyResolver.cs is a very simple implementation of the resolver.

In case you are wondering what Microsoft.Extensions.DependencyInjection is. It is nothing more than a lightweight DI abstractions and basic implementation (github page). It is currently used in ASP.NET Core and EF Core, but nothing prevents you from using it in “normal” .NET. You can integrate it with more feature-rich IoC frameworks. At the moment it looks like Autofac has the best integration and nice documentation in place. See OWIN integration.

Rest is just usual IoC clutter. See the gist

I hope this blog post helps you with integrating Microsoft.Extensions.DependencyInjection in WebApi hosted via OWIN.