Ninject: entity object cannot be referenced by multiple instances of IEntityChangeTracker

Question

I am starting to use Ninject in my MVC5 code-first app. Here\'s my NinjectWebCommon.cs:

private static IKernel CreateKernel()
    {
        var kernel = new Stan         


        

Answer 1

You should be using NUGET package Ninject.Web.Mvc if you aren't already. This configures your application ready to use Ninject, other than your bindings. It looks like you are reasonably familiar with the bindings side of things already from what I can see in your CreateKernel() method.

Once your bindings are in place, you should not be creating Kernels in your controllers, this is because the Ninject.Web.Mvc library configures Ninject to create your controllers for you under the hood. Therefore any dependencies that you add to them should be automatically resolved.

So, you can use constructor injection to resolve your dependencies:

public class ExecutiveController : Controller
{
    private IExecutiveRepository ExecutiveRepository;
    private IUserRepository UserRepository;
    private IExecutiveSectionRepository ExecutiveSectionRepository;
    private IExecutiveSectionMappingRepository ExecutiveSectionMappingRepository;
    private IContentRepository ContentRepository;

    public ExecutiveController(
         IExecutiveRepository executiveRepository,
         IUserRepository userRepository,
         IExecutiveSectionRepository executiveSectionRepository,
         IExecutiveSectionMappingRepository executiveSectionMappingRepository,
         IContentRepository contentRepository)
    {

         // Set the field values
         this.ExecutiveRepository = executiveRepository,
         this.UserRepository = userRepository,
         this.ExecutiveSectionRepository = executiveSectionRepository,
         this.ExecutiveSectionMappingRepository = executiveSectionMappingRepository,
         this.ContentRepository = contentRepository;
    }

    public ActionResult Index(int id)
    {
        // Use one of your dependencies...
        var executive = this.executiveRepository.GetExecutiveById(id);
    }
}

Or you can use the [Inject] attribute which has the same effect:

public class ExecutiveController : Controller
{
    [Inject]
    public IExecutiveRepository executiveRepository { get; set; }

    [Inject]
    public IUserRepository userRepository { get; set; }

    [Inject]
    public IExecutiveSectionRepository executiveSectionRepository { get; set; }

    [Inject]
    public IExecutiveSectionMappingRepository executiveSectionMappingRepository { get; set; }

    [Inject]
    public IContentRepository contentRepository { get; set; }

    public ExecutiveController()
    {

    }

    public ActionResult Index(int id)
    {
        // Use one of your dependencies...
        var executive = this.executiveRepository.GetExecutiveById(id);
    }
}