integration asp.net web api with autofac and owin

There is an example project showing Web API in conjunction with OWIN self hosting

https://github.com/autofac/Examples/tree/master/src/WebApiExample.OwinSelfHost

https://github.com/autofac/Examples/blob/master/src/WebApiExample.OwinSelfHost/Startup.cs

Owin

https://autofaccn.readthedocs.io/en/latest/integration/owin.html

OWIN (Open Web Interface for .NET) is a simpler model for composing web-based applications without tying the application to the web server. To do this, a concept of “middleware” is used to create a pipeline through which requests travel.

Due to the differences in the way OWIN handles the application pipeline (detecting when a request starts/ends, etc.) integrating Autofac into an OWIN application is slightly different than the way it gets integrated into more “standard” ASP.NET apps. You can read about OWIN and how it works on this overview.

The important thing to remember is that order of OWIN middleware registration matters. Middleware gets processed in order of registration, like a chain, so you need to register foundational things (like Autofac middleware) first.

Quick Start

To take advantage of Autofac in your OWIN pipeline:

• Reference the Autofac.Owin package from NuGet.
• Build your Autofac container.
• Register the Autofac middleware with OWIN and pass it the container.

Web api integration with owin

https://autofaccn.readthedocs.io/en/latest/integration/webapi.html#owin-integration

If you are using Web API as part of an OWIN application, you need to:

• Do all the stuff for standard Web API integration - register controllers, set the dependency resolver, etc.
• Set up your app with the base Autofac OWIN integration.
• Add a reference to the Autofac.WebApi2.Owin NuGet package.
• In your application startup class, register the Autofac Web API middleware after registering the base Autofac middleware.

A common error in OWIN integration is use of the GlobalConfiguration.Configuration.

In OWIN you create the configuration from scratch.

You should not reference GlobalConfiguration.Configuration anywhere when using the OWIN integration.