c# - How exactly IAppBuilder.CreatePerOwinContext<T> should be used?

Question

I'm confused on how the OWIN CreatePerOwinContext method is to be used. As far as I can see it's a poor mans DI mechanism. Yet, I fail to see how to use it.

We can register a type/implementation at the Startup sequence like:

app.CreatePerOwinContext<IUserService>(() => {
     return new UserService() as IUserService;
});

Then how do we resolve to that later on. Documentation says it can be retrieved via Get method. But Get<T> expects a string parameter, which is the key to that entry in the Enviornment IDictionary? How can I know the key in this case?

IUserService userService = context.Get<IUserService>(???);

Answer 1

You can use typeof to get the key parameter:

HttpContext.GetOwinContext().Get<ApplicationDbContext>(typeof(ApplicationDbContext).ToString());

Also, Microsoft.AspNet.Identity.Owin assembly contains the parameterless version of Get<T>() method, so you can use it if you already have ASP.NET Identity in your project.