Adding Web API and API documentation to an existing MVC project

Question

I have successfully added a web api controller to an existing MVC4 application.

I would like to have the api documentation functionality as is

Answer 1

I just ran into this issue. Here's what it was for me.

I'd had the Help pages working on a previous project (w/ MVC 5 and Web API 2) so I knew it was something different in my new project. Turned out in the old (working) project I was only doing DI in the WebApi controllers, not the MVC controllers. I didn't need DI in the MVC controllers, so I simply commented out the code bootstrapping the UnityDependencyResolver as the MVC dependency resolver (in my case the UnityMvcActivator class).

Obviously this won't be an option for everyone, but where not, @Adrian Brown's answer looks like your best bet until this is fixed.