At the moment I am working on challenging project that is powered by Sitecore 8.2and follows Helix principles.
Last week I implemented a Feature, that has an MVC form posting back to its controller (here I mean native MVC, not Web Forms for Marketers) module. "Not a big deal" - I thought initially... and spent more time that positively expected until finally got it implemented.
The difference between Helix project and more traditional Sitecore MVC application is that in Helix your assets - controllers, views, statics etc. are kept within an individual project for a particular Feature (or Foundation, or Project - depending on what functionality you're implementing).
Prerequisites.
I assume you already have your Helix solution ready (you may use Habitat, as an "instance" of Helix). So let's start with Sitecore.
I create a page called Test under website root using one of page templates. Next, a rendering is required to be assigned into a placeholder on a page. I create a controller rendering named Test and put it under this feature folder (also called Test). Please notice, that I have to specify controller with fully qualified name with a name of assembly where this controller resides.
Tip: do not forget to publish your items, unless you're working in a live mode from Master DB directly.
Next, let's create a project structure in Solution Explorer. As we're building a Feature, create a solution folder under Feature folder in Visual Studio and name it Test (as a feature name). Create a class library project within that folder following Helix naming conventions YourSolution.Feature.Test with the same namespace and assembly name. The easiest probably would be simply to copy project folder from an existing feature and change namespace / types there.
You need to have Web config to the project root. Please ensure you are referencing the same .NET version as set in Target Framework of the project, in my example it is 4.5.2:
Also you need to have web.config within the /Views folder to make IntelliSense work properly
Below is the minimum references you'll need to have. DataAnnotations library is not essential, for sure, but is included because it'll be needed at step 3):
At this stage we're set. Let's mote to the next step - creating and wiring up a MVC form on a rendering.
References:
Sitecore Helix Documentation