How to Use Ninject as Dependency Injection with ASP.NET MVC

Table of Contents

1. Introduction
2. About Ninject
3. Get Ninject Library
4. Interface
5. Class
6. Dependency Resolve Class in Ninject
7. Set Up Ninject Dependency in Application Global Class
8. Setup Ninject Dependency in Ninject Module
9. Use Ninject Dependency in ASP.NET MVC Controller
10. Unit Test in Ninject + ASP.NET MVC App
11. Mocking Data in Unit Test - Ninject + Moq
12. Conclusion
13. Other Choices for Dependency Injection in .NET

Introduction

This post demonstrates how to use Ninject as a dependency injection framework in an ASP.NET MVC application, including setup, unit testing, and mocking with Moq.

About Ninject

• NuGet Ninject

• Ninject.org

• Blog - About Ninject in C#

• Code Project - Ninject Example

Get Ninject Library

Install-Package Ninject -Version 3.2.2

Interface

In C#, for using Dependency Injection you'll define your interface and a class that implements this interface. Once you define the interface and bind the relation via Ninject, you can use this interface at other layers without knowing the detail implementation.

namespace NinjectConstructorInjectionWeb
{
    public interface ISamurai
    {
        string GetData();
    }
}

Class

namespace NinjectConstructorInjectionWeb
{
    public class Samurai : ISamurai
    {
        public string GetData()
        {
            return "my data";
        }
    }
}

Dependency Resolve Class in Ninject

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Mvc;
using Ninject.Syntax;
using Ninject;

namespace NinjectConstructorInjectionWeb
{
    public class NinjectDependencyResolver : IDependencyResolver
    {
        private readonly IResolutionRoot _resolutionRoot;

        public NinjectDependencyResolver(IResolutionRoot kernel)
        {
            _resolutionRoot = kernel;
        }

        public object GetService(Type serviceType)
        {
            return _resolutionRoot.TryGet(serviceType);
        }

        public IEnumerable GetServices(Type serviceType)
        {
            return _resolutionRoot.GetAll(serviceType);
        }
    }
}

Set Up Ninject Dependency in Application Global Class

With Ninject, you can either set up binding as follows, or set up binding as individual modules by inheriting from the NinjectModule class.

protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            RegisterGlobalFilters(GlobalFilters.Filters);
            RegisterRoutes(RouteTable.Routes);


            // setting for Ninject
            IKernel kernel = new StandardKernel();

            kernel.Bind().To();

            DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
        }

Setup Ninject Dependency in Ninject Module

public  class  MyModule  : NinjectModule
     {
         public  override  void  Load()
         {
             Bind().To()
                 .WithConstructorArgument("kernel" , this .Kernel);
         }
     }

Use Ninject Dependency in ASP.NET MVC Controller

The beauty of doing dependency injection in an ASP.NET MVC controller is passing the interface to the constructor. The user/client doesn't need to know about the interface's implementation logic.

private readonly ISamurai _samurai;
public HomeController(ISamurai samurai)
{
    _samurai = samurai;
}

public ActionResult Test()
{
    // you should see "my data" here.
    ViewBag.Hi = _samurai.Attach();
    return View();
}

Unit Test in Ninject + ASP.NET MVC App

Another important benefit of dependency injection with Ninject is unit testing. Because everything is interface-based, you can set up different data in unit tests to test your actual logic.

[TestMethod ]
         public  void  Product()
         {
 			  ISamurai  testService = new  Samurai();

 			  HomeController  controller = new  HomeController (testService);

            controller.Product();
         }

Mocking Data in Unit Test - Ninject + Moq

Use Ninject + Moq + Unit Test so you can mock temporary data for the interface and pass it to your controller.

public  static  IProductBzService  GetProductService()
         {
             Mock  mock = new  Mock ();
             mock.SetupGet(x => x.Id).Returns(1);
             mock.SetupGet(x => x.Name).Returns("test name" );
             mock.SetupGet(x => x.Price).Returns(11.11m);
             mock.SetupGet(x => x.Unit).Returns(2);
             mock.Setup(x => x.Total()).Returns(999.999m);

             return  mock.Object;
         }

Conclusion

Ninject is a useful C# .NET library for dependency injection. However, it appears that it is no longer actively maintained, so it may become a legacy dependency injection library in the future.

Other Choices for Dependency Injection in .NET

I would recommend using Autofac. It is well documented and supports different .NET libraries, such as ASP.NET Web Forms, MVC, WebAPI 1, WebAPI 2, SignalR, RIA, OWIN, WCF, MEF, NHibernate, and Moq.

1. Autofac

2. Castle Windsor

3. StructureMap

4. Spring.NET

5. Unity

6. Puzzle.NFactory

7. Ninject

8. S2Container.NET

9. PicoContainer.NET

10. LinFu