Troubles with dependency injection - entity-framework

Question

I am working on an ASP.NET WebAPI using OWIN. To manage the instances of DBContext (Entity Framework), I try to use Ninject. However, when I call a controller, the programm returns an error:
The controller cannot be created, missing constructor.
Could you tell me what is going wrong here?
My Controller Class:
public class Testcontroller
{
private IApplicationDbContext _context;
public Testcontroller(IApplicationDbContext context)
{
_context = context;
}
}
This is the Ninject-File:
public static class NinjectWebCommon
{
private static readonly Bootstrapper bootstrapper = new Bootstrapper();
public static void Start()
{
DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
bootstrapper.Initialize(CreateKernel);
}
public static void Stop()
{
bootstrapper.ShutDown();
}
private static IKernel CreateKernel()
{
var kernel = new StandardKernel();
try
{
kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();
kernel.Bind<IApplicationDbContext>().To<ApplicationDbContext>();
GlobalConfiguration.Configuration.DependencyResolver = new NinjectDependencyResolver(kernel);
RegisterServices(kernel);
return kernel;
}
catch
{
kernel.Dispose();
throw;
}
}
private static void RegisterServices(IKernel kernel)
{
}
}
Ninject Dependency Scope:
public class NinjectDependencyScope : IDependencyScope
{
IResolutionRoot resolver;
public NinjectDependencyScope(IResolutionRoot resolver)
{
this.resolver = resolver;
}
public object GetService(Type serviceType)
{
if (resolver == null)
throw new ObjectDisposedException("this", "This scope has been disposed");
return resolver.TryGet(serviceType);
}
public System.Collections.Generic.IEnumerable<object> GetServices(Type serviceType)
{
if (resolver == null)
throw new ObjectDisposedException("this", "This scope has been disposed");
return resolver.GetAll(serviceType);
}
public void Dispose()
{
IDisposable disposable = resolver as IDisposable;
if (disposable != null)
disposable.Dispose();
resolver = null;
}
}
// This class is the resolver, but it is also the global scope
// so we derive from NinjectScope.
public class NinjectDependencyResolver : NinjectDependencyScope, IDependencyResolver
{
IKernel kernel;
public NinjectDependencyResolver(IKernel kernel) : base(kernel)
{
this.kernel = kernel;
}
public IDependencyScope BeginScope()
{
return new NinjectDependencyScope(kernel.BeginBlock());
}
}
The Entity Framework DbContext-Class:
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>, IApplicationDbContext
{
public ApplicationDbContext()
: base("DefaultConnection", throwIfV1Schema: false)
{
Configuration.ProxyCreationEnabled = false;
Configuration.LazyLoadingEnabled = false;
}
public virtual DbSet<Models.Team> Teams { get; set; }
public static ApplicationDbContext Create()
{
return new ApplicationDbContext();
}
}
public interface IApplicationDbContext
{
DbSet<Models.Team> Teams { get; set; }
int SaveChanges();
Task<int> SaveChangesAsync(CancellationToken cancellationToken);
}
I tried to follow this tutorial: http://www.peterprovost.org/blog/2012/06/19/adding-ninject-to-web-api
What have I done wrong here?
Thanks in advance!

Answer 1

Unless there was a serious omission in you controller code, your controller is not inheriting from ApiController, as is expected with Web Api
public class TestController : ApiController {
private IApplicationDbContext _context;
public Testcontroller(IApplicationDbContext context) {
_context = context;
}
}

Answer 2

UPDATE
I tried to set up everything from scratch using this: http://www.alexzaitzev.pro/2014/11/webapi2-owin-and-ninject.html
For some reason, it now works out perfectly fine.
Thank you for your support!