InvalidOperationException in EF Repository with Ninject - c#

I make custom authentication for my ASP.NET MVC project and I use EF 6.1.3 and Ninject.MVC 3.2.1. I use repositories and unit of work patterns.
I want validate unique username at registration in my view model with custom ValidationAttribute.
Sometimes my repository throw InvalidOperationException with description:
the operation cannot be completed because the dbcontext has been disposed.
This is my Ninject configuration:
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<DbContext>().To<MyPortfolioDbContext>().InRequestScope();
kernel.Bind(typeof(IDbRepository<>)).To(typeof(EfRepository<>));
kernel.Bind<Func<IUnitOfWork>>().ToMethod(ctx => () => ctx.Kernel.Get<EfUnitOfWork>());
kernel.Bind<IUnitOfWork>().To<EfUnitOfWork>();
kernel.Bind<IAuthenticationManager>().To<AuthenticationManager>();
kernel.Bind(k => k
.From("MyPortfolio.Services.Authentication", "MyPortfolio.Services.Data")
.SelectAllClasses()
.BindDefaultInterface());
}
This is my ValidationAttribute:
public class RegistrationValidator : ValidationAttribute
{
[Inject]
public IDbRepository<User> Users { get; set; }
public override bool IsValid(object value)
{
string username = (string)value;
bool result = true;
if (this.Users.FirstOrDefault(u => u.Username == username) != null)
{
result = false;
}
return result;
}
}
And this is my repository:
public class EfRepository<T> : IDbRepository<T> where T : class, IAuditInfo, IDeletableEntity
{
private IDbSet<T> dbSet;
private DbContext context;
public EfRepository(DbContext context)
{
if (context == null)
{
throw new ArgumentException("An instance of DbContext is required to use this repository.", nameof(context));
}
this.context = context;
this.dbSet = this.context.Set<T>();
}
//another methods
//the method that throw an exception
public T FirstOrDefault(Expression<Func<T, bool>> filterExpression)
{
return this.dbSet.Where(x => !x.IsDeleted).FirstOrDefault(filterExpression);
}
//another methods
}
If you need another code of my project please tell me.
My hypothesis is that on injecting the repository into ValidationAttribute, Ninject used old dbContext. What is your opinion.

Related

EF Core In-Memory Database Not Saving To DbSet

Overview
I am currently unit/integration testing my repository pattern with the in-memory database EF Core provides. I am on version 6.0.1 for the Microsoft.EntityFrameworkCore.InMemory nuget and using Visual Studio 2022. I am running into issues saving data to the database. Below I have included snippets of my code.
My data model:
public class Example : IExample
public Guid Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
My base repository class:
public class Repository<T> : IRepository<T> where T : class
private readonly DbSet<T> _dbSet;
private readonly DbContext _db;
public Repository(DbContext db)
{
_dbSet = db.Set<T>();
_db = db;
}
public virtual async Task Add(T entity)
{
await _dbSet.AddAsync(entity);
}
public virtual async Task<int> SaveAsync(CancellationToken token = default)
{
return await _db.SaveChangesAsync(token);
}
My repository class:
public class ExampleRepo : Repository<Example>
public ExampleRepo(ExampleContext db) : base(db)
{
}
My DbContext Class
I can show my IEntityConfiguration class for the ExampleBuilder shown below if it is needed but I don't believe that to be the problem.
public class ExampleContext : DbContext
private readonly IHttpContextAccessor? _httpContextAccessor;
public ExampleContext(DbContextOptions<ExampleContext> options) : base(options)
{
if (options == null) throw new ArgumentNullException(nameof(options));
}
public ExampleContext(DbContextOptions<ExampleContext> options, IHttpContextAccessor httpContextAccessor)
: base(options)
{
if (options == null) throw new ArgumentNullException(nameof(options));
_httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException(nameof(httpContextAccessor));
}
public DbSet<Example>? Examples { get; set; }
protected override void OnModelCreating(ModelBuilder builder)
{
var assembly = Assembly.GetAssembly(typeof(ExampleBuilder));
if (assembly is null)
{
throw new DataException("Could not find the assembly containing the designated model builder");
}
builder.ApplyConfigurationsFromAssembly(assembly);
foreach (var entity in builder.Model.GetEntityTypes())
{
entity.SetSchema("dbo");
}
}
public override Task<int> SaveChangesAsync(CancellationToken token = default)
{
foreach (var entry in ChangeTracker.Entries()
.Where(x => x.State is EntityState.Added or EntityState.Modified or EntityState.Deleted))
{
var user = _httpContextAccessor?.HttpContext?.User?.Identity?.Name ?? "User";
entry.Property("ModifiedBy").CurrentValue = user;
if (entry.State == EntityState.Added)
{
entry.Property("CreatedBy").CurrentValue = user;
}
if (entry.State != EntityState.Deleted) continue;
entry.State = EntityState.Modified;
entry.Property("IsActive").CurrentValue = false;
}
return base.SaveChangesAsync(token);
}
My DbContext factory method:
private ExampleContext GenerateDbContext()
{
var options = new DbContextOptionsBuilder<ExampleContext>()
.UseInMemoryDatabase(Guid.NewGuid().ToString())
.Options;
return new ExampleContext(options);
}
My unit/integration test utilizing xUnit and NET6.0
[Fact]
public async Task GetAllEntities_ShouldReturnEntities_WhenEntitiesExist()
{
// Arrange
// I used Bogus nuget for single source for generating valid models
var entity = ExampleFaker.GetModelFaker()
.Generate();
await using var context = GenerateDbContext();
var repo = new ExampleRepo(context);
await repo.Add(entity);
var changes = await repo.SaveAsync();
// Act
// Consulted this link already. Bottom answer is most related
//https://stackoverflow.com/questions/46184937/dbcontext-not-returning-local-objects
var response = await repo.GetAll();
// Assess
TestOutputHelper.WriteLine($"Added entity to repository: {entity.ToJson()}");
TestOutputHelper.WriteLine("Expected entities saved: 1");
TestOutputHelper.WriteLine($"Actual entities saved: {changes}");
TestOutputHelper.WriteLine($"Response: {response?.ToJson()}");
// Assert
Assert.Equal(1, changes);
Assert.NotNull(response);
Assert.NotEmpty(response);
Assert.IsType<List<Example>>(response.ToList());
}
Analysis & Issue
The changes variable returns 1 so I interpret this as EF does not have any issue with my model as well as I would think it successfully saved my model in the in-memory database. However, during my GetAll retrieval, no data is returned. When I debug and look into the repository private members, it shows the DbSet is empty so it is not the GetAll method causing the issue either. Since this is also just within the scope of the unit test, I don't think my Program.cs configuration has anything to do with the issue I am seeing. I have been looking at this for quite a while and can't figure out the small detail I am probably missing for the life of me.
Thank you for your help in advance.

Circular component dependency detected Repository pattern with autofac dependency injections

I am working on implementing the generic repository pattern with db Context and Autofac DI, and I am using the constructor based on dependency injections.
I have created the three layers repository pattern which are:
Infrastructure layer
Model layer
Services layer
Now, I am using this architecture in MVC web application when I try to pass the IContactService interface in ContactController and run the application.
I am getting the circular dependency detected error. Followings are my project code.
Repository code:
public class Repository<T> : IRepository<T> where T : class
{
private InvoiceBillingDbContext db;
private DbSet<T> dbSet;
public Repository()
{
db = new InvoiceBillingDbContext();
dbSet = db.Set<T>();
}
public IEnumerable<T> GetAll()
{
return dbSet.ToList();
}
public T GetById(object Id)
{
return dbSet.Find(Id);
}
public void Insert(T obj)
{
dbSet.Add(obj);
Save();
}
public void Update(T obj)
{
db.Entry(obj).State = EntityState.Modified;
Save();
}
public void Delete(object Id)
{
T getObjById = dbSet.Find(Id);
dbSet.Remove(getObjById);
}
public void Save()
{
db.SaveChanges();
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (this.db != null)
{
this.db.Dispose();
this.db = null;
}
}
}
public void AddRange(List<T> obj)
{
dbSet.AddRange(obj);
Save();
}
public IEnumerable<T> Get(Expression<Func<T, bool>> predicate)
{
return dbSet.Where(predicate);
}
}
Interface IRepository
public interface IRepository<T> where T : class
{
IEnumerable<T> GetAll();
T GetById(object Id);
IEnumerable<T> Get(Expression<Func<T, bool>> predicate);
void Insert(T obj);
void AddRange(List<T> obj);
void Update(T obj);
void Delete(Object Id);
void Save();
}
My ContactRepository
public class ContactRepository:Repository<Contact>, IContactRepository
{
private IContactRepository _contractRepo;
public ContactRepository(IContactRepository contractRepo)
{
this._contractRepo = contractRepo;
}
}
My ContactRepository Interface
public interface IContactRepository:IRepository<Contact>
{
}
My Contact Service
public interface IContactService
{
void AddContact(Contact contact);
IEnumerable<Contact> GetContactsByTypeId(int typeId);
}
public class ContactService : IContactService
{
private readonly IContactRepository _contactRepository;
public ContactService(IContactRepository contactRepository)
{
this._contactRepository = contactRepository;
}
public void AddContact(Contact contact)
{
_contactRepository.Insert(contact);
}
public IEnumerable<Contact> GetContactsByTypeId(int typeId)
{
return _contactRepository.Get(i => i.TypeID == typeId);
}
}
My Controller
public class ContactController : Controller
{
// GET: Contact
private IContactService _contactService;
public ContactController(IContactService contactService)
{
this._contactService = contactService;
}
public ActionResult Index()
{
return View(new ContactViewModel());
}
public ActionResult AddContact(ContactViewModel contact)
{
if (ModelState.IsValid)
{
var _contactMapper = Mapper.Map<ContactViewModel, Contact>(contact);
_contactService.AddContact(_contactMapper);
ViewBag.Message = "Successfully Saved";
return View("Index",new ContactViewModel());
}
ViewBag.Message = "Error Occur Please try Again!";
return View("Index", new ContactViewModel());
}
}
And Autofac Dependency Injection
public static void ConfigureContainer()
{
var builder = new ContainerBuilder();
// Register all controllers in the Mvc Application assembly
builder.RegisterControllers(typeof(MvcApplication).Assembly);
// Registered Warehouse Reservoir Service
builder.RegisterType<InvoiceRepository>().As<IInvoiceRepository>();
// Registration Service Layer Service
builder.RegisterType<InvoiceService>().As<IInvoiceService>();
builder.RegisterGeneric(typeof(Repository<>)).As(typeof(IRepository<>));
// Registered Warehouse Reservoir Service
builder.RegisterType<JournalVoucherRepository>().As<IJournalVoucherRepository>();
// Registration Service Layer Service
builder.RegisterType<JournalVoucherService>().As<IJournalVoucherService>();
// Registered Warehouse Reservoir Service
builder.RegisterType<ContactRepository>().As<IContactRepository>();
// Registration Service Layer Service
builder.RegisterType<ContactService>().As<IContactService>();
// Registration filter
builder.RegisterFilterProvider();
var container = builder.Build();
// Setting Dependency Injection Parser
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}
You've only got one implementation of IContactRepository. You've also got a generic IRepository<T>.
Your implementation of IContactRepository gets another IContactRepository injected into it. So you're recursively resolving the same class and injecting it into itself.
public class ContactRepository:Repository<Contact>, IContactRepository
{
private IContactRepository _contractRepo;
// In order to resolve IContractRepository, the container has to
// resolve another IContractRepository to inject into it.
// And another one to inject into that. It's recursive.
public ContactRepository(IContactRepository contractRepo)
{
this._contractRepo = contractRepo;
}
}
Your example doesn't show how ContactRepository uses the IContactRepository that gets inject into it. But this
public interface IContactRepository:IRepository<Contact>
{
}
reveals that it's using the exact same methods found in IRepository<Contact>, because IContactRepository doesn't have any methods other than those.
So you most likely just need to modify ContactRepository to inject IRepository<Contact>, not IContactRepository.
public class ContactRepository:Repository<Contact>, IContactRepository
{
private IRepository<Contact> _contractRepo;
public ContactRepository(IRepository<Contact> contractRepo)
{
this._contractRepo = contractRepo;
}
}
That could be easy to overlook since both interfaces have exactly the same methods.

Unit of Work and Repository Pattern in MVC controller constructor injection using Unity not doing any changes to database

1.) I am a building new MVC application with 3 tier project architecture having:
Common Project with entities
Business/Service holding interfaces and logic classes and
Data holding repositories, interfaces, DbContext and UnitOfWorkclasses. I am using Unity Config to register dependencies, DbContext and UnitOfWork.
2.) I created a repository for each table and one generic repository that does basic CRUD operations.
Example Entity residing in Common Project:
public class MenuSecd
{
[Key, Column(Order = 0)]
public string prg_module { get; set; }
[Key, Column(Order = 1)]
public int prg_numb { get; set; }
[Key, Column(Order = 2)]
public string menu_level { get; set; }
}
My generic Entity Logic Interface residing in Business Project:
public interface IEntityLogic<T> : ILogic where T : class
{
void Create(T entity);
void Delete(T entity);
IEnumerable<T> GetAll();
void Update(T entity);
}
Entity Logic Class:
public abstract class EntityLogic<T> : IEntityLogic<T> where T : class
{
IUnitOfWork _unitOfWork;
IGenericRepository<T> _repository;
public EntityLogic(IUnitOfWork unitOfWork, IGenericRepository<T> repository)
{
_unitOfWork = unitOfWork;
_repository = repository;
}
public virtual void Create(T entity)
{
if(entity == null)
{
throw new ArgumentNullException(nameof(entity));
}
_repository.Add(entity);
_unitOfWork.Commit();
}
}
Example Business Logic class for the entity defined in Common Project:
public class MenuSecdLogic : EntityLogic<MenuSecd>, IMenuSecdLogic
{
IUnitOfWork _unitOfWork;
IMenuSecdRepository _repository;
public MenuSecdLogic(IUnitOfWork unitOfWork, IMenuSecdRepository repository) : base(unitOfWork, repository)
{
_unitOfWork = unitOfWork;
_repository = repository;
}
public List<MenuSecd> GetItems(string usrgrp_id)
{
return _repository.GetItems(usrgrp_id);
}
}
My Generic Repository in Data Project looks like:
public abstract class GenericRepository<T> : IGenericRepository<T> where T : class
{
protected DbContext _entities;
protected readonly IDbSet<T> _dbset;
public GenericRepository(DbContext context)
{
_entities = context;
_dbset = context.Set<T>();
}
public virtual T Add(T entity)
{
return _dbset.Add(entity);
}
public virtual T Delete(T entity)
{
return _dbset.Remove(entity);
}
public virtual void Edit(T entity)
{
_entities.Entry(entity).State = EntityState.Modified;
}
}
Repository Interface for the same Entity is defined as:
public interface IMenuSecdRepository : IGenericRepository<MenuSecd>
{
List<MenuSecd> GetItems(string usrgrp_id);
}
Repository class for above mentioned interface is:
public class MenuSecdRepository : GenericRepository<MenuSecd>, IMenuSecdRepository
{
public MenuSecdRepository(DbContext context) : base(context)
{
}
public List<MenuSecd> GetItems(string usrgrp_id)
{
return _dbset.Where(m => m.usrgrp_id == usrgrp_id).ToList();
}
}
My DbContext looks like:
public class DashboardContext : DbContext
{
public DashboardContext() : base("Name=DBEntities")
{
}
public DbSet<MenuSecd> menusecd { get; set; }
public override int SaveChanges()
{
var modifiedEntries = ChangeTracker.Entries().Where(x => x.State == EntityState.Added || x.State == EntityState.Modified);
//future custom implementation like auditing
return base.SaveChanges();
}
}
My UnitOfWork looks like:
public sealed class UnitOfWork : IUnitOfWork
{
private DbContext _dbContext;
public UnitOfWork(DbContext context)
{
_dbContext = context;
}
public int Commit()
{
return _dbContext.SaveChanges();
}
//disposes current object
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
//disposes all external resources
private void Dispose(bool disposing)
{
if (disposing)
{
if (_dbContext != null)
{
_dbContext.Dispose();
_dbContext = null;
}
}
}
}
My controller:
public class DashController : Controller
{
private readonly IMenuSecdLogic _menuSecdLogic;
public DashController(IMenuSecdLogic menuSecdLogic)
{
_menuSecdLogic = menuSecdLogic;
}
public void Save()
{
var menuSecd = new menuSecd();
//populate all fields for entity MenuSecd
_menuSecdLogic.Create(menuSecd);
}
}
My Unity Config in App_Start looks like :
public static void RegisterTypes(IUnityContainer container)
{
container.RegisterType<DbContext, DashboardContext>();
container.RegisterType<IUnitOfWork, UnitOfWork>();
container.RegisterType(typeof(IGenericRepository<>), typeof(GenericRepository<>));
container.RegisterType<IMenuSecdLogic, MenuSecdLogic>();
container.RegisterType<IMenuSecdRepository, MenuSecdRepository>();
}
So when run above project everything builds fine. But when controller calls:
_menuSecdLogic.Create(menuSecd);
It reaches Entity Logic and adds a new entity to _repository at :
_repository.Add(entity);
_unitOfWork.Commit();
But when it hits next line to actually save it to database which is :
return _dbContext.SaveChanges();
in UnitOfWork.cs file.
It comes to dashboardContext where it finally have to save it to database. But it does execute :
var modifiedEntries = ChangeTracker.Entries().Where(x => x.State == EntityState.Added || x.State == EntityState.Modified);
return base.SaveChanges();
But nothing changes in database. There will be no record in database. To test I have added modifiedEntries to see if it is in context or not. By the time control reaches this point I see no modified entries at all. But in EntityLogic.cs it does add a new entity to local entities in repository.
I am not sure what is happening with UnitOfWork here. I ran SQL Profiler to see if it is hitting database or not. Interestingly it is not hitting database at all. But if my make following changes to EntityLogic like this:
public virtual void Create(T entity)
{
if(entity == null)
{
throw new ArgumentNullException(nameof(entity));
}
_repository.Add(entity);
_repository.Save();
//_unitOfWork.Commit();
}
It hits Database and records gets saved fine. But I am not getting why it is neither tracking changes nor hitting database if I use _unitOfWork.Commit() which I want to do. Please help.
It looks like your issue is the scope of your DbContext. Your UnitOfWork and GenericRepository<T> classes are getting different instances.
Not super familiar with Unity, but it looks like you want to use something like this for your DbContext registration:
container.RegisterType<DbContext, DashboadContext>(new PerRequestLifetimeManager());
This will create a single DashboardContext for each request, and your UnitOfWork and GenericRepository<T> classes will be working within the same context.

AutoFac DbContext issue - cannot be used while the model is creating

I'm having a few issues getting started with AutoFac and IoC. We've got a working application however, I'm starting from scratch with this one and can't see where the differences between the two are.
I am testing this with a simple AJAX page which is calling the Service layer via a ServiceStack API. When using MockRepositories this works fine so I know that side of things is working.
However when I replace the mocks with ones that use Entity Framework, although all the registrations appear to be correct and working, I get the error "The context cannot be used while the model is being created."
I have included my code below:
public class SomeObject
{
public int Id { get; set; }
}
public class IoCExampleContext : DbContext, IIoCExampleContext
{
public IDbSet<SomeObject> SomeObjects { get; set; }
static IoCExampleContext()
{
Database.SetInitializer(new IoCExampleDatabaseInitilizer());
}
public IoCExampleContext(string connectionStringName)
: base(connectionStringName)
{
Configuration.ProxyCreationEnabled = false;
}
public IoCExampleContext()
: this("name=IoCExample")
{}
public string ConnectionString
{
get { return Database.Connection.ConnectionString; }
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
BuildModels(modelBuilder);
}
private void BuildModels(DbModelBuilder builder)
{
var typeToUse = typeof(SomeObjectModelBuilder);
var namespaceToUse = typeToUse.Namespace;
var toReg = Assembly
.GetAssembly(typeToUse)
.GetTypes()
.Where(type => type.Namespace != null && type.Namespace.StartsWith(namespaceToUse))
.Where(type => type.BaseType.IsGenericType && type.BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));
foreach (object configurationInstance in toReg.Select(Activator.CreateInstance))
{
builder.Configurations.Add((dynamic)configurationInstance);
}
}
}
public class IoCExampleDatabaseInitilizer : CreateDatabaseIfNotExists<IoCExampleContext>
{
protected override void Seed(IoCExampleContext context)
{
}
}
public interface IRepository<TEntity> where TEntity : class
{
IQueryable<TEntity> GetQuery();
IEnumerable<TEntity> GetAll();
IEnumerable<TEntity> Where(Expression<Func<TEntity, bool>> predicate);
// ...Various "standard" CRUD calls
}
public class GenericRepository<TEntity> : IRepository<TEntity> where TEntity : class
{
protected DbContext _context;
private readonly DbSet<TEntity> _dbSet;
public GenericRepository(DbContext context)
{
_context = context;
_dbSet = _context.Set<TEntity>();
}
public IQueryable<TEntity> GetQuery()
{
return _dbSet;
}
public IEnumerable<TEntity> GetAll()
{
return GetQuery().AsEnumerable();
}
public IEnumerable<TEntity> Where(Expression<Func<TEntity, bool>> predicate)
{
return GetQuery().Where(predicate);
}
// ...Various "standard" CRUD calls
public void Dispose()
{
OnDispose(true);
}
protected void OnDispose(bool disposing)
{
if (disposing)
{
if (_context != null)
{
_context.Dispose();
_context = null;
}
}
}
}
public class DependencyBootstrapper
{
private ContainerBuilder _builder;
public IContainer Start()
{
_builder = new ContainerBuilder();
_builder.RegisterFilterProvider();
RegisterControllers();
return _builder.Build();
}
private void RegisterControllers()
{
RegisterAssembly(Assembly.GetExecutingAssembly());
_builder.RegisterModelBinderProvider();
RegisterPerLifetimeConnections();
RegisterRepositories();
RegisterServices();
}
private void RegisterAssembly(Assembly assembly)
{
_builder.RegisterModelBinders(assembly);
_builder.RegisterControllers(assembly);
}
private void RegisterRepositories()
{
_builder.RegisterGeneric(typeof(GenericRepository<>)).As(typeof(IRepository<>));
_builder.RegisterType<GenericRepository<SomeObject>>().As<IRepository<SomeObject>>();
//... More registrations
}
private void RegisterServices()
{
_builder.RegisterType<SomeObjectService>().As<ISomeObjectService>();
//... More registrations
}
private void RegisterPerLifetimeConnections()
{
const string connectionStringName = "IoCExample";
_builder.RegisterType<IoCExampleContext>()
.As<DbContext>()
.WithParameter("connectionStringName", connectionStringName)
.InstancePerLifetimeScope();
_builder.Register(c => new HttpContextWrapper(HttpContext.Current))
.As<HttpContextBase>();
}
}
I don't know if it's relevant but as we can't get access to the global.asax methods we're calling the bootstrapper through PreApplicationStartMethod.OnPreApplicationStart (which as far as I am aware, is pretty much the same thing as Application_Start).
What's a little concerning is that when I enable Multiple Active Result Sets on the connection string it works -which would suggest to me that I'm registering the DbContext incorrectly and it's spanning multiple contexts.
Can anyone spot where I'm going wrong?
The connection string is the issue. Ensure you've set it up correctly in your web/app.comfig.

EF4.1 Code First DbContext: The operation cannot be completed because the DbContext has been disposed

I have a controller action that gets invoked directly, but throws this error:
The operation cannot be completed because the DbContext has been disposed.
I have only found solutions online regarding deferred excecution, but I don't think that applies here, because everywhere I use the context (in this instance) I call either .ToList() or .FirstOrDefault(). Here is my code:
CONTROLLER CONTENT
private IUnitOfWork UnitOfWork;
public MyFavouritesController(
IAccountServices accountServices,
IUnitOfWork unitOfWork
)
{
AccountServices = accountServices;
UnitOfWork = unitOfWork;
}
public ActionResult Index()
{
int? id = AccountServices.GetCurrentUserId();
if (!id.HasValue)
{
return RedirectToAction("Login", "Account", new { ReturnUrl = this.HttpContext.Request.Url.AbsolutePath });
}
var user = UnitOfWork.UserRepo.Get(id.Value, "Favourites", "Favourites.County", "Favourites.Country");
//THE ABOVE CALL GETS THE ERROR
//.....
return View();
}
REPOSITORY BASE CLASS
public class RepositoryBase<C, T> : IDisposable
where C:DbContext, new()
where T : ModelBase
{
private DbContext _context;
public DbContext Context
{
get
{
if (_context == null)
{
_context = new C();
this.AllowSerialization = true;
}
return _context;
}
set
{
_context = value;
}
}
public virtual T Get(int Id, params string[] includes)
{
if (Id > 0)
{
var result = Context.Set<T>().Where(t => t.Id == Id);
foreach (string includePath in includes)
{
result = result.Include(includePath);
}
return result.FirstOrDefault(); //This is where the error occurs.
}
else
{
throw new ApplicationException("Id is zero (0).");
}
}
//... (More CRUD methods)
public void Dispose()
{
if (Context != null)
{
Context.Dispose(); //Debugger never hits this before the error
}
}
}
UNIT OF WORK CLASS
public class UnitOfWork:IUnitOfWork
{
public UnitOfWork(
//... DI of all repos
IUserRepository userRepo
)
{
//... save repos to an local property
UserRepo = userRepo;
//create a new instance of the context so that all the repo's have access to the same DbContext
Context = new Context();
//assign the new context to all the repo's
//...
UserRepo.Context = Context;
}
public Context Context { get; set; }
public IUserRepository UserRepo { get; set; }
//... (some more repositories)
public void Dispose()
{
Context.Dispose(); //THIS IS NOT HIT AT ALL
}
}
LASTLY, THE MODEL CONTAINER HAS THIS LINE
_Instance.RegisterType<IUnitOfWork, UnitOfWork>(new PerThreadLifetimeManager());
As you can see, the index action will recieve a new instance of UnitOfWork which contains a new DbContext object. But at the first call to this context, it throws the above error. This pattern works everywhere else in my code.
Thanks
UPDATE
The answer below was to use a perRequestLifetimeManager. Here is the implimentation of one in unity:
public class HttpRequestLifetimeManager : LifetimeManager
{
private string _key = Guid.NewGuid().ToString();
public override object GetValue()
{
if (HttpContext.Current != null && HttpContext.Current.Items.Contains(_key))
return HttpContext.Current.Items[_key];
else
return null;
}
public override void RemoveValue()
{
if (HttpContext.Current != null)
HttpContext.Current.Items.Remove(_key);
}
public override void SetValue(object newValue)
{
if (HttpContext.Current != null)
HttpContext.Current.Items[_key] = newValue;
}
}
I noticed you're using a PerThreadLifetimeManager to control the creation and disposal of your unit of work class. You should probably change it to something like PerRequestLifetimeManager if your IoC container supports that.
Its because your are disposing the Unit Of Work, after wich you are requesting your data, store your data in a Variable after the query then you can release the Unit Of Work instance as well.

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