C# How to use interfaces

Question

This is a relatively straight forward question. But I was wondering what the correct usage is for accessing a method inside a separate project through the use of an interface.

Answer 1

First off, you need to have your Test class inherit/implement ITest.

class Test : ITest
{
    public string TestMethod() { return "test"; }
}

Then, in your controller class, you need to initialize test -- whether directly, or in the constructor.

public class HomeController : Controller
{
    public ITest test = new Test();
    public ActionResult Index()
    {
        return Content(test.TestMethod());
    }
}

Although in many cases, you should prefer to create the ITest outside of the constructor and pass it in or something.