In our project we use MefControllerFactory, these are the codes which we set at application_start in global.asax as ControllerBuilder.Current.SetControllerFactory(new Project.Helper.MefControllerFactory(container));
The problem is when we run .NET Profiler in result, it gives memory leak problem even we dispose controllers in "ReleaseController" method. The original message is "An instance is disposed but still reachable from one or more roots. Since a disposed instance should normally no longer be used, this can indicate a memory leak. Investigate the instance to find out whether the instance is unintentionally kept alive, or if the issue can be ignored."
Is there any solution for this problem ?
The second message is:
"Disposed instance with direct EventHandler roots
A disposed instance is directly rooted by an EventHandler, i.e., the instance is only used as the target of an EventHandler and it cannot be reached from any other root without passing through a delegate. Since a disposed instance should no longer be used and EventHandlers are a common cause of memory leaks, this issue is a strong indication of a memory leak."
public class MefControllerFactory : IControllerFactory
{
private CompositionContainer _container;
private DefaultControllerFactory defaultControllerFactory;
public MefControllerFactory(CompositionContainer container)
{
_container = container;
this.defaultControllerFactory = new DefaultControllerFactory();
}
#region IControllerFactory Members
public IController CreateController(System.Web.Routing.RequestContext requestContext, string controllerName)
{
IController controller = null;
controller = _container.GetExportedValueOrDefault<IController>(controllerName);
if (controller == null)
return this.defaultControllerFactory.CreateController(requestContext, controllerName);
return controller;
}
public void ReleaseController(IController controller)
{
IDisposable disposable = controller as IDisposable;
if (disposable != null)
disposable.Dispose();
}
#endregion
public System.Web.SessionState.SessionStateBehavior GetControllerSessionBehavior(System.Web.Routing.RequestContext requestContext, string controllerName)
{
return System.Web.SessionState.SessionStateBehavior.Default;
}
}
Thanks...
Here's the MEF-based Controller Factory I created for the code samples for my book:
public class MefControllerFactory : DefaultControllerFactory
{
private readonly CompositionContainer container;
private readonly Dictionary<IController, Lazy<object, object>> exports;
private readonly object syncRoot;
public MefControllerFactory(CompositionContainer container)
{
if (container == null)
{
throw new ArgumentNullException("container");
}
this.container = container;
this.exports = new Dictionary<IController, Lazy<object, object>>();
this.syncRoot = new object();
}
protected override IController GetControllerInstance(
RequestContext requestContext, Type controllerType)
{
var export = this.container.GetExports(
controllerType, null, null).Single();
var controller = (IController)export.Value;
lock (this.syncRoot)
{
this.exports.Add(controller, export);
}
return controller;
}
public override void ReleaseController(IController controller)
{
lock (this.syncRoot)
{
var export = this.exports[controller];
this.exports.Remove(controller);
this.container.ReleaseExport(export);
}
base.ReleaseController(controller);
}
}
In MEF, you can only Release object graphs by releasing the Export - not the exported value.
Related
For MVC app using MEF, sometimes I get the erorr ""
I have a .NET solution with
One MVC Web application project and,
Many class libraries projects which take care of authentication, getting configurations, making external API calls etc.
I have configured the MEF as shown below through the code and deployed this on Web Server using IIS. Observed the below error couple of times, after which I tried to load the page multiple times but it still throws the same error.
Once I refreshed the application pool, then only the error disappears. I had been trying hard to debug and understand the error, but with no success. Am I misconfiguring MEF anywhere?
Global.asax:
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
AreaRegistration.RegisterAllAreas();
GlobalConfiguration.Configure(WebApiConfig.Register);
RouteConfig.RegisterRoutes(RouteTable.Routes);
var pluginFolders = LoadMefComponents();
Bootstrapper.Compose(pluginFolders);
IControllerFactory mefControllerFactory = new MefControllerFactory(Bootstrapper.Container);
ControllerBuilder.Current.SetControllerFactory(mefControllerFactory);
}
protected List<string> LoadMefComponents()
{
var pluginFolders = new List<string>();
string ModulesPath = CommonUtility.GetApplicationDirectory();
var plugins = Directory.GetDirectories(ModulesPath).ToList();
plugins.ForEach(path =>
{
var directoryInfo = new DirectoryInfo(path);
pluginFolders.Add(directoryInfo.Name);
});
return pluginFolders;
}
}
MEFControllerFactory.cs: This file resides in App_Start
public class MefControllerFactory : DefaultControllerFactory
{
private readonly CompositionContainer _container;
private readonly Dictionary<IController, Lazy<object, object>> exports;
private readonly object syncRoot;
public MefControllerFactory(CompositionContainer container)
{
if (container == null)
{
throw new ArgumentNullException("container");
}
this._container = container;
this.exports = new Dictionary<IController, Lazy<object, object>>();
this.syncRoot = new object();
}
protected override IController GetControllerInstance(System.Web.Routing.RequestContext requestContext, Type controllerType)
{
Lazy<object, object> export = _container.GetExports(controllerType, null, null).FirstOrDefault();
var controller = null == export ? base.GetControllerInstance(requestContext, controllerType)
: (IController)export.Value;
lock (this.syncRoot)
{
this.exports.Add(controller, export);
}
return controller;
}
public override void ReleaseController(IController controller)
{
lock (this.syncRoot)
{
var export = this.exports[controller];
this.exports.Remove(controller);
// this._container.ReleaseExport(export);
}
((IDisposable)controller).Dispose();
}
}
Bootstrapper.cs: This file resides in App_Start
public class Bootstrapper
{
private static CompositionContainer compositionContainer;
private static bool IsLoaded = false;
public static CompositionContainer Container
{
get { return compositionContainer; }
set { compositionContainer = value; }
}
public static void Compose(List<string> pluginFolders)
{
if (IsLoaded) return;
var catalog = new AggregateCatalog();
catalog.Catalogs.Add(new AssemblyCatalog(Assembly.GetExecutingAssembly()));
catalog.Catalogs.Add(new DirectoryCatalog(CommonUtility.GetApplicationDirectory()));
compositionContainer = new CompositionContainer(catalog);
compositionContainer.ComposeParts();
IsLoaded = true;
}
public static T GetInstance<T>(string contractName = null)
{
var type = default(T);
if (compositionContainer == null) return type;
if (!string.IsNullOrWhiteSpace(contractName))
type = compositionContainer.GetExportedValue<T>(contractName);
else
type = compositionContainer.GetExportedValue<T>();
return type;
}
}
CommonUtility.cs: This file resides in App_Start
public class CommonUtility
{
public static string GetApplicationDirectory()
{
string codeBase = Assembly.GetExecutingAssembly().CodeBase;
UriBuilder uri = new UriBuilder(codeBase);
string path = Uri.UnescapeDataString(uri.Path);
return Path.GetDirectoryName(path);
}
}
HomeController.cs:
[CommonExceptionFilter]
public class HomeController : Controller
{
private IConfigurationManager _configurationManager;
[ImportingConstructor]
public HomeController()
{
_configurationManager = Bootstrapper.GetInstance<IConfigurationManager>();
}
public async Task<ActionResult> Index()
{
//Business Logic
return View()
}
}
IConfigurationManager.cs
[InheritedExport]
public interface IConfigurationManager
{
string GetConfigurationValue(string keyName)
}
ConfigurationManager.cs
[PartCreationPolicy(CreationPolicy.Shared)]
public class ConfigurationManager: IConfigurationManager
{
[ImportingConstructor]
public ConfigurationManager()
{
}
public string GetConfigurationValue(string keyName)
{
return "";
}
}
IHttpHandlers Used In The MVC Project:
public class CommonServiceHandler : HttpTaskAsyncHandler, IRequiresSessionState
{
private ICommonServiceHandlerManager _commonServiceHandlerManager;
public CommonServiceHandler()
{
_commonServiceHandlerManager = Bootstrapper.GetInstance<ICommonServiceHandlerManager>();
}
public override bool IsReusable
{
get
{
return false;
}
}
}
This error indicates that at least one controller exists that its constructor parameters are not resolved.
Every controller needs a constructor to be resolved at run-time. By default every c# class has a default (parameter-less) constructor that can be called when an instance of the class is needed to be created.
However, after defining an explicit constructor, you lose the default constructor, therefore, you need to make sure that all your controllers have either a parameter-less constructor or if instead they have a parametric constructor the parameters need to be registered through dependency injection.
I'm buold MVC4 C# website.
I have base controller with constructor
public BaseController(IUnityContainer container, SessionContext context)
The problem is that container is shared globally and when i try to resolve or register objects they are shared through sessions. On the other hand SessionContext (parameter) comes only is unique to user session. I want container to be unique for user sessions (to be able resolve unique objects for user sessions), but i don't know how to implement it.
I have UnityControllerFactory as follows:
public class UnityControllerFactory : DefaultControllerFactory
{
private IUnityContainer container;
public UnityControllerFactory(IUnityContainer container){
this.container = container;
this.RegisterTypes();
}
protected override IController GetControllerInstance(RequestContext context, Type controllerType)
{
if (controllerType != null)
{
return this.container.Resolve(controllerType) as IController;
}
return null;
}
private void RegisterTypes(){
container.RegisterType<SessionContext>(new UnityPerSessionLifetimeManager("private.SessionContext"));
container.RegisterType<DataService>(new UnityPerSessionLifetimeManager("private.Service"));
}
}
and lifetime manager
public class UnityPerSessionLifetimeManager : LifetimeManager
{
private string sessionKey;
public UnityPerSessionLifetimeManager(string sessionKey)
{
this.sessionKey = sessionKey;
}
public override object GetValue()
{
return HttpContext.Current.Session[this.sessionKey];
}
public override void RemoveValue()
{
HttpContext.Current.Session.Remove(this.sessionKey);
}
public override void SetValue(object newValue)
{
HttpContext.Current.Session[this.sessionKey] = newValue;
}
}
Ok, after searching Google, here and several ASP/MVC forums I am bound to have to ask what the hell I am doing wrong here.
I have a good start to my application, an ok understanding of DI, IoC and am using the Repository, Service and UnitOfWork patterns. When I attempt to load a controller that needs the DI from Unity, it's as if unity is not resolving any of the registered items, or that I have done it poorly. From all the examples I can see for this version (not the version that creates the Bootstrap.cs file that is then called from Global.asax) I am doing what others have done with no love from Unity.
My core question is: Have I setup/configured Unity to inject the items into the controller constructor as needed or not. If I have, any ideas why it's not working like examples I have seen?
I keep getting the error that the AssetController needs to have a parameterless public constructor. If I add one, then it uses it without the DI and if I don't add one, then it yells about not having it.
Thanks, code below.
UnityConfig.cs
namespace CARS.web.App_Start
{
/// <summary>
/// Specifies the Unity configuration for the main container.
/// </summary>
public class UnityConfig
{
#region Unity Container
private static Lazy<IUnityContainer> container = new Lazy<IUnityContainer>(() =>
{
var container = new UnityContainer();
RegisterTypes(container);
return container;
});
/// <summary>
/// Gets the configured Unity container.
/// </summary>
public static IUnityContainer GetConfiguredContainer()
{
return container.Value;
}
#endregion
/// <summary>Registers the type mappings with the Unity container.</summary>
/// <param name="container">The unity container to configure.</param>
/// <remarks>There is no need to register concrete types such as controllers or API controllers (unless you want to
/// change the defaults), as Unity allows resolving a concrete type even if it was not previously registered.</remarks>
public static void RegisterTypes(IUnityContainer container)
{
// NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
// container.LoadConfiguration();
// TODO: Register your types here
// container.RegisterType<IProductRepository, ProductRepository>();
container.RegisterType<IDataContext, CARSDEMOContext>(new PerRequestLifetimeManager())
.RegisterType<IAssetService, AssetService>()
.RegisterType<IUnitOfWork, UnitOfWork>()
.RegisterType<IRepository<Asset>, Repository<Asset>>();
//.RegisterType<AssetController>(new InjectionConstructor(typeof(IAssetService), typeof(IUnitOfWork)));
}
}
}
AssetController.cs (constructor portion where I am doing the injection params)
namespace CARS.web.Controllers
{
public class AssetController : Controller
{
private readonly IAssetService _assetService;
private readonly IUnitOfWork _unitOfWork;
public AssetController(IAssetService assetService, IUnitOfWork unitOfWork)
{
_assetService = assetService;
_unitOfWork = unitOfWork;
}
//other methods for CRUD etc stripped for brevity
}
}
IAssetService.cs (first param is the assetService )
namespace CARS.service
{
public interface IAssetService : IService<Asset>
{
Task<IEnumerable<Asset>> GetAsync();
Task<Asset> FindAsync(Guid id);
Asset Add(Asset asset);
Asset Update(Asset asset);
void Remove(Guid id);
}
}
AssetService.cs (concrete implementation for IAssetService interaction)
namespace CARS.service
{
public class AssetService : Service<Asset>, IAssetService
{
private readonly IRepositoryAsync<Asset> _repository;
public AssetService(IRepositoryAsync<Asset> repository) : base(repository)
{
_repository = repository;
}
public Task<IEnumerable<Asset>> GetAsync()
{
//return _repository.Query().SelectAsync();
return _repository.Query().SelectAsync();
}
public Task<Asset> FindAsync(Guid id)
{
return _repository.FindAsync(id);
}
public Asset Add(Asset asset)
{
_repository.Insert(asset);
return asset;
}
public Asset Update(Asset asset)
{
_repository.Update(asset);
return asset;
}
public void Remove(Guid id)
{
_repository.Delete(id);
}
}
}
IUnitOfWork.cs (this is from Long Le's Generic UofW and Repository - http://genericunitofworkandrepositories.codeplex.com/)
namespace Repository.Pattern.UnitOfWork
{
public interface IUnitOfWork : IDisposable
{
int SaveChanges();
Task<int> SaveChangesAsync();
void Dispose(bool disposing);
IRepository<TEntity> Repository<TEntity>() where TEntity : IObjectState;
void BeginTransaction();
bool Commit();
void Rollback();
}
}
UnitOfWork.cs (again from Long Le's framework)
namespace Repository.Pattern.Ef6
{
public class UnitOfWork : IUnitOfWork, IUnitOfWorkAsync
{
#region Private Fields
private readonly IDataContextAsync _dataContext;
private bool _disposed;
private ObjectContext _objectContext;
private Dictionary<string, object> _repositories;
private DbTransaction _transaction;
#endregion Private Fields
#region Constuctor/Dispose
public UnitOfWork(IDataContextAsync dataContext)
{
_dataContext = dataContext;
}
public void Dispose()
{
if (_objectContext != null && _objectContext.Connection.State == ConnectionState.Open)
_objectContext.Connection.Close();
Dispose(true);
GC.SuppressFinalize(this);
}
public virtual void Dispose(bool disposing)
{
if (!_disposed && disposing)
_dataContext.Dispose();
_disposed = true;
}
#endregion Constuctor/Dispose
public int SaveChanges()
{
return _dataContext.SaveChanges();
}
public IRepository<TEntity> Repository<TEntity>() where TEntity : IObjectState
{
return RepositoryAsync<TEntity>();
}
public Task<int> SaveChangesAsync()
{
return _dataContext.SaveChangesAsync();
}
public Task<int> SaveChangesAsync(CancellationToken cancellationToken)
{
return _dataContext.SaveChangesAsync(cancellationToken);
}
public IRepositoryAsync<TEntity> RepositoryAsync<TEntity>() where TEntity : IObjectState
{
if (_repositories == null)
_repositories = new Dictionary<string, object>();
var type = typeof (TEntity).Name;
if (_repositories.ContainsKey(type))
return (IRepositoryAsync<TEntity>) _repositories[type];
var repositoryType = typeof (Repository<>);
_repositories.Add(type, Activator.CreateInstance(repositoryType.MakeGenericType(typeof (TEntity)), _dataContext, this));
return (IRepositoryAsync<TEntity>) _repositories[type];
}
#region Unit of Work Transactions
public void BeginTransaction()
{
_objectContext = ((IObjectContextAdapter) _dataContext).ObjectContext;
if (_objectContext.Connection.State != ConnectionState.Open)
{
_objectContext.Connection.Open();
_transaction = _objectContext.Connection.BeginTransaction();
}
}
public bool Commit()
{
_transaction.Commit();
return true;
}
public void Rollback()
{
_transaction.Rollback();
((DataContext)_dataContext).SyncObjectsStatePostCommit();
}
#endregion
// Uncomment, if rather have IRepositoryAsync<TEntity> IoC vs. Reflection Activation
//public IRepositoryAsync<TEntity> RepositoryAsync<TEntity>() where TEntity : EntityBase
//{
// return ServiceLocator.Current.GetInstance<IRepositoryAsync<TEntity>>();
//}
}
}
Updated to include the SetResolver info from UnityMvcActivator.cs
using System.Linq;
using System.Web.Mvc;
using Microsoft.Practices.Unity.Mvc;
[assembly: WebActivatorEx.PreApplicationStartMethod(typeof(CARS.web.App_Start.UnityWebActivator), "Start")]
namespace CARS.web.App_Start
{
/// <summary>Provides the bootstrapping for integrating Unity with ASP.NET MVC.</summary>
public static class UnityWebActivator
{
/// <summary>Integrates Unity when the application starts.</summary>
public static void Start()
{
var container = UnityConfig.GetConfiguredContainer();
FilterProviders.Providers.Remove(FilterProviders.Providers.OfType<FilterAttributeFilterProvider>().First());
FilterProviders.Providers.Add(new UnityFilterAttributeFilterProvider(container));
DependencyResolver.SetResolver(new UnityDependencyResolver(container));
// TODO: Uncomment if you want to use PerRequestLifetimeManager
Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(UnityPerRequestHttpModule));
}
}
}
I have read/tried the following info/data and nothing has fixed it:
The type IUserStore`1 does not have an accessible constructor
How to add MVC 5 authentication to Unity IoC?
Types not resolving with Unity [MVC 5]
I have ready where one must write a ControllerFactory for Unity to be able to do this, but that seems quite a bit of work when all the examples I have found simply have the config registered, and the injection apparently happening on the controllers and other classes as need.
And finally the error:
The following server error was encountered:
An error occurred when trying to create a controller of type 'CARS.web.Controllers.AssetController'. Make sure that the controller has a parameterless public constructor.Details are:
at System.Web.Mvc.DefaultControllerFactory.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) at System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName) at System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory) at System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionSte p.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Thanks
You need to set the DependencyResolver. I cant see the code in the example you provided where this is done.
Once setting up your UnityContainer and registering your types, you need to set the System.Web.MVC.DependencyResolver.
DependencyResolver.SetResolver(new UnityDependencyResolver(container));
You may have missed (like I did) to register the async types in UnityConfig.cs
Check if you have this:
container.RegisterType<IUnitOfWork, UnitOfWork>(new PerRequestLifetimeManager())
.RegisterType<IUnitOfWorkAsync, UnitOfWork>(new PerRequestLifetimeManager())
.RegisterType<IDataContextAsync, SomeDBContext>(new PerRequestLifetimeManager())
.RegisterType<IDataContext, SomeDBContext>(new PerRequestLifetimeManager())
.RegisterType<ISomeService, SomeService>(new PerRequestLifetimeManager())
.RegisterType<IRepositoryAsync<Some>, Repository<Some>>(new PerRequestLifetimeManager());
1:
Uncomment in file UnityMvcActivator this line:
Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(UnityPerRequestHttpModule));
2:
Basic registration with Unity + UnitOfwork + Repository
this must exists in file: UnityConfig:
container.RegisterType<IDataContextAsync, KlussendirectContext>(new PerRequestLifetimeManager());
container.RegisterType<IDataContext, KlussendirectContext>(new PerRequestLifetimeManager());
container.RegisterType<IUnitOfWork, UnitOfWork>(new PerRequestLifetimeManager());
container.RegisterType<IUnitOfWorkAsync, UnitOfWork>(new PerRequestLifetimeManager());
3:
When you use Dependency Injection in a controller(api) then a parameter less constructor should exists:
e.g.
public MyNameController() : base(){}
If followed those steps, it should work (Edit, Insert, Delete, etc..)
This is my controller
public class SuggestionController : ApiController
{
public ISuggestionRepository Repository { get; private set; }
public SuggestionController(ISuggestionRepository repository)
{
this.Repository = repository;
}
// to post suggestion
[HttpPost]
[ActionName("PostSuggestion")]
public HttpResponseMessage PostSuggestion(Suggestion suggestion)
{
var answerCorrect = this.Repository.CreateSuggestion(suggestion);
if (answerCorrect == true)
return Request.CreateResponse(HttpStatusCode.OK);
else
return Request.CreateResponse(HttpStatusCode.Conflict);
}
}
and this is my RegisterServices method in NinjectWebCommon.cs
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<ICompetitionRepository>().To(typeof(CompetitionRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<Competition>());
kernel.Bind<ISubmissionRepository>().To(typeof(SubmissionRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<Submission>());
kernel.Bind<IUserRepository>().To(typeof(UserRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<User>());
kernel.Bind<ISuggestionRepository>().To(typeof(SuggestionRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<Suggestion>());
}
But am getting an exception that my suggestion controller does not have a default constructor and its showing a 500 internal server when am hitting the controller from a client app
I know that we get the exception of controller not having default constructor if the ninject dependency is not working properly but the below is another controller i have implemeneted similar to suggestion controller and its working absolutely fine.
public IUserRepository Repository { get; private set; }
public SSOController(IUserRepository repository)
{
this.Repository = repository;
}
[HttpPost]
[ActionName("PostUser")]
public HttpResponseMessage PostUser([FromBody]string id)
{
var accessToken = id;
var client = new FacebookClient(accessToken);
dynamic result = client.Get("me", new { fields = "name,email" });
string name = result.name;
string email = result.email;
var existingUser = this.Repository.FindByUserIdentity(name);
if (existingUser == null)
{
var newUser = new User
{
Username = name,
Email = email,
};
var success = this.Repository.CreateAccount(newUser);
if (!success)
{
return Request.CreateResponse(HttpStatusCode.InternalServerError);
}
//return created status code as we created the user
return Request.CreateResponse<User>(HttpStatusCode.Created, newUser);
}
return Request.CreateResponse(HttpStatusCode.OK);
}
}
I have no idea where am going wrong. Please let me know if u have any suggestions.
EDIT:
my Global.asax
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
AuthConfig.RegisterAuth();
GlobalConfiguration.Configuration.IncludeErrorDetailPolicy =
IncludeErrorDetailPolicy.Always;
}
Dependency resolver am using
// Provides a Ninject implementation of IDependencyScope
// which resolves services using the Ninject container.
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());
}
}
and calling it in CreateKernel() method in NinjectWebCommon
private static IKernel CreateKernel()
{
var kernel = new StandardKernel();
kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();
RegisterServices(kernel);
// Install our Ninject-based IDependencyResolver into the Web API config
GlobalConfiguration.Configuration.DependencyResolver = new NinjectDependencyResolver(kernel);
return kernel;
}
Suggestion Repository
public class SuggestionRepository : Repository<Suggestion>, ISuggestionRepository
{
public SuggestionRepository(IServiceContext<Suggestion> servicecontext)
: base(servicecontext)
{ }
public bool CreateSuggestion(Suggestion suggestion)
{
this.ServiceContext.Create(suggestion);
this.ServiceContext.Save();
return true;
}
}
ISuggestionRepository
public interface ISuggestionRepository
{
bool CreateSuggestion(Suggestion suggestion);
}
Repository
public abstract class Repository<T>
{
public IServiceContext<T> ServiceContext { get; private set; }
public Repository(IServiceContext<T> serviceContext)
{
this.ServiceContext = serviceContext;
}
}
IserviceContext
public interface IServiceContext<T>
{
IQueryable<T> QueryableEntities { get; }
void Create(T entity);
void Update(T entity);
void Delete(T entity);
void Save();
}
Since you're using WebApi, you will need to use the WebApi extension for Ninject. Unfortunately, the current Ninject.WebApi nuget package is out of date, and doesn't work with the released version of WebApi.
Temporarily, until Remo gets around to updating Ninject.WebApi to the release version, you can use Ninject.WebApi-RC http://nuget.org/packages/Ninject.Web.WebApi-RC
http://www.eyecatch.no/blog/2012/06/using-ninject-with-webapi-rc/
EDIT:
To recap the information discussed in comments, Here are the recommendations:
1) Use Ninject.MVC3 and Ninject.Web.WebApi (but use Ninject.Web.WebApi-RC until the official is updated) as discussed above. Do not use a custom DependencyResolver, and let Ninject.Web.Mvc and .WebApi do their job.
2) Change your bindings to this:
kernel.Bind<ICompetitionRepository>().To<CompetitionRepository>();
... similar bindings
3) Add a generic binding for your ServiceContext
kernel.Bind(typeof(IServiceContext<>)).To(typeof(InMemoryDataContext<>));
I think the problem is you're using the ApiController.
Controllers and apiControllers are using a different dependancy injection container.
Both of them however expose the same methods.
If the working controller is inheriting the Controller class then that's your cause.
For a work around take a look at
this topic
I have faced the same issue.
This is how I rectified:
I created a WebContainerManager which is just a static wrapper around container.
Static container wrappers useful when you don't control instantiation and can't rely on injection - e.g. action filter attributes
public static class WebContainerManager
{
public static IKernel GetContainer()
{
var resolver = GlobalConfiguration.Configuration.DependencyResolver as NinjectDependencyResolver;
if (resolver != null)
{
return resolver.Container;
}
throw new InvalidOperationException("NinjectDependencyResolver not being used as the MVC dependency resolver");
}
public static T Get<T>()
{
return GetContainer().Get<T>();
}
}
Inside your controller, call your empty constructor like this with no parameters:
public SuggestionController() : this(WebContainerManager.Get<ISuggestionRepository>())
{
}
This should work.
This technique i got from the book on MVC4 by Jamie Kurtz #jakurtz.
You probably need to do some dependency injection so you can inject the ISuggestionRepository parameter on your SuggestionController constructor. To do that you need to override methods in the DefaultControllerFactory class to customize the creation of controllers. Since you are using NInject, you can have something like:
public class NInjectControllerFactory : DefaultControllerFactory
{
private IKernel kernel = new StandardKernel(new CustomModule());
protected override IController GetControllerInstance(System.Web.Routing.RequestContext requestContext, Type controllerType)
{
return controllerType == null ? null : (IController)kernel.Get(controllerType);
}
public class CustomModule : NinjectModule
{
public override void Load()
{
this.Bind<ICompetitionRepository>().To(typeof(CompetitionRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<Competition>());
this.Bind<ISubmissionRepository>().To(typeof(SubmissionRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<Submission>());
this.Bind<IUserRepository>().To(typeof(UserRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<User>());
this.Bind<ISuggestionRepository>().To(typeof(SuggestionRepository))
.WithConstructorArgument("serviceContext", new InMemoryDataContext<Suggestion>());
}
}
}
Then in your Global.asax.cs, you can add a line to swap out the controller factory
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterRoutes(RouteTable.Routes);
ControllerBuilder.Current.SetControllerFactory(new NInjectControllerFactory());
}
In mvc asp.net, I can override a factory to create my controllers, and so put a reference to my IOC just here. Doing So every interface needed by the constructor of my controllers will be feeded by my IOC .
Is there some common way to do it using Silverlight?
At the moment I only found to use the kernel of Ninject everywhere :
public partial class MyUserControlSL
{
public MyUserControlSL()
{
DataContext = new MyViewModel(Kernel.Get<IMyRepository>());
InitializeComponent();
}
}
eg using StructureMap and MVC:
public class ControllerFactory : DefaultControllerFactory
{
protected override IController GetControllerInstance(
RequestContext requestContext, Type controllerType)
{
IController result = null;
try
{
if (controllerType != null)
{
result = ObjectFactory.GetInstance(controllerType)
as Controller;
}
else
{
return base.GetControllerInstance(
requestContext, controllerType);
}
}
catch (StructureMapException)
{
System.Diagnostics.Debug.WriteLine(
ObjectFactory.WhatDoIHave());
throw;
}
return result;
}
}
public AController(IServiceA serviceA)
{
if (serviceA == null)
{
throw new Exception("IServiceA cannot be null");
}
_ServiceA = serviceA;
}
public ServiceA(IRepositoryA repository)
{
if (repository == null)
{
throw new Exception(
"the repository IRepositoryA cannot be null");
}
_Repository = repository;
}
Thanks for your help, please ask if it is not clear..
In Silverlight you should use a bootstrapper at composition root to wire up your entire object graph. It could be the Application class app.xml.cs and look similar to
public partial class App : Application
{
private void Application_Startup(object sender, StartupEventArgs e)
{
Bootstrapper bootstrapper = new Bootstrapper();
bootstrapper.Run();
}
}
In general this should be sufficant but if you need a separate Factory class for your views, take a look at
Keeping the DI-container usage in the composition root in Silverlight and MVVM.
For Silverlight you may use PRISM framework with custom IoC container.
Autofac has built in support for silverlight: http://weblogs.asp.net/dwahlin/archive/2010/01/03/using-autofac-as-an-ioc-container-in-silverlight-applications.aspx