C# Ninject binding results in empty repository in standard MVC class AccountController

Question

I'm making an application using the MVC framework in C#. We want to make a repository 'uitlenerRepository' which contains all of our users.

I bound the repository using Ninject in NinjectWebCommon in the RegisterServices class:

public static class NinjectWebCommon 
{
    private static readonly Bootstrapper bootstrapper = new Bootstrapper();

    /// <summary>
    /// Starts the application
    /// </summary>
    public static void Start() 
    {
        DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
        DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
        bootstrapper.Initialize(CreateKernel);
    }

    /// <summary>
    /// Stops the application.
    /// </summary>
    public static void Stop()
    {
        bootstrapper.ShutDown();
    }

    /// <summary>
    /// Creates the kernel that will manage your application.
    /// </summary>
    /// <returns>The created kernel.</returns>
    private static IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        try
        {
            kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
            kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();

            RegisterServices(kernel);
            return kernel;
        }
        catch
        {
            kernel.Dispose();
            throw;
        }
    }

    /// <summary>
    /// Load your modules or register your services here!
    /// </summary>
    /// <param name="kernel">The kernel.</param>
    private static void RegisterServices(IKernel kernel)
    {

        kernel.Bind<IMateriaalRepository>().To<MateriaalRepository>().InRequestScope();
        kernel.Bind<IReservatieRepository>().To<ReservatieRepository>().InRequestScope();
        kernel.Bind<IUitlenerRepository>().To<UitlenerRepository>();
        kernel.Bind<UitleenAppContext>().ToSelf().InRequestScope();
    }        
}

As you can see I tried the same method with other repositories, which were successfull. The only difference between the other repositories is that I make a new one in the predefined class 'AccountController'. Because in that class, I'm able to easily add new users. In this class I made an empty constructor and added it as a third parameter.

public class AccountController : Controller
    {
        private ApplicationSignInManager _signInManager;
        private ApplicationUserManager _userManager;
        private IUitlenerRepository uitlenerRepository;

    public AccountController()
    {
    }

    public AccountController(ApplicationUserManager userManager, ApplicationSignInManager signInManager, IUitlenerRepository uitlenerRepository)
    {
        UserManager = userManager;
        SignInManager = signInManager;
        this.uitlenerRepository = uitlenerRepository;
    }

We can't add new users to the repository. When debugging, I found out that the value of the repository is null, inidcating that the binding is not working properly.

Picture of debugging

Does anyone know how to resolve this problem?

Your controller has multiple constructors: this is an anti-pattern. — Steven

BatteryBackupUnit BatteryBackupUnit · Accepted Answer · 2016-04-01T16:41:57

The AccountController() ctor is being used, that's why it's null. Ninject will choose the constructor with the most parameters it can resolve. I suspect that either ApplicationUserManager or ApplicationSignInManager need a binding. I suggest you remove the AccountController() ctor - the one without any parameters - then ninject will throw an exception and tell you exactly why it can't use the other ctor.

C# Ninject binding results in empty repository in standard MVC class AccountController

1 Answers