混合与否asp.net mvc应用程序和Web API

Question

I have an MVC application. I have build two layers BLL and DAL and it is ready to use.

I'd like to add a service layer: I learned about Asp.Net Web API and I'd like to use it to build this layer.

In the book of Adam Freeman ( Pro Asp.net MVC4) I read this

You can freely mix regular controllers and API controllers in a project. In fact, you will usually need to if you want to support HTML clients because API controllers will only return object data and will not render a view.

So, I'd like to know in which cases I have to use one of this solution :

1. Using Asp.Net MVC application and a web API ( as a service layer)
2. Mixing the two applications in a web API application

Answer 1

Yes it is fine to use WebAPI controllers and MVC controllers in the same project, or in separate projects, but WebAPI serves a completely separate duty.

WebAPI controllers cannot act as a "service layer" as such for your application, as it simply exposes portions of functionality as a RESTful service that can be called upon using HTTP requests (such as AJAX calls from the client).

You should use your service layer (business layer) within both your MVC and WebAPI controllers and only expose the data that you need through WebAPI. It is not possible to use the WebAPI methods in place of your business layer.