Heres my error:
Autofac.Core.DependencyResolutionException: None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'ConnectCx.Web.PluginUI.MVC5.Services.DefaultService' can be invoked with the available services and parameters:
Cannot resolve parameter 'ConnectCx.Web.PluginUI.MVC5.Repository.IRepository1[ConnectCx.Web.PluginUI.MVC5.Models.ViewModels.DependancyTestViewModel] dependancyRepository' of constructor 'Void .ctor(ConnectCx.Web.PluginUI.MVC5.Repository.IRepository1[ConnectCx.Web.PluginUI.MVC5.Models.ViewModels.DependancyTestViewModel])'.
Here's my Global
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
var builder = new ContainerBuilder();
// Register our MVC controllers.
builder.RegisterControllers(typeof(MvcApplication).Assembly);
//Register our Services
//builder.RegisterType(typeof(DefaultService)).AsImplementedInterfaces();
//builder.RegisterType<IRepository>();
//builder.RegisterType(typeof(IRepository)).AsImplementedInterfaces();
builder.RegisterType<DefaultService>().As<IDefaultService>().SingleInstance().PreserveExistingDefaults();
// OPTIONAL: Register model binders that require DI.
builder.RegisterModelBinders(Assembly.GetExecutingAssembly());
builder.RegisterModelBinderProvider();
// OPTIONAL: Register web abstractions like HttpContextBase.
builder.RegisterModule<AutofacWebTypesModule>();
// OPTIONAL: Enable property injection in view pages.
builder.RegisterSource(new ViewRegistrationSource());
// OPTIONAL: Enable property injection into action filters.
builder.RegisterFilterProvider();
// Set the dependency resolver to be Autofac.
var container = builder.Build();
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}
heres my Irepository
namespace ConnectCx.Web.PluginUI.MVC5.Repository
{
public interface IRepository<T> where T : class
{
T Get(object id);
void Attach(T entity);
IQueryable<T> GetAll();
void Insert(T entity);
void Delete(T entity);
void Update(T entity);
void SubmitChanges(); //need?
T Find(Expression<Func<T, bool>> predicate);
IQueryable<T> SearchFor(Expression<Func<T, bool>> predicate);
T GetById(int id);
}
}
heres my Default Service
public class DefaultService : IDefaultService
{
private readonly IRepository<DependancyTestViewModel> _dependancyRepository;
public DefaultService(IRepository<DependancyTestViewModel> dependancyRepository)
{
this._dependancyRepository = dependancyRepository;
}
public virtual string DependancyStringTest()
{
var test = _dependancyRepository.GetAll();//expect to blowup for test
return "hello world, wasup?";
}
}
heres my default service interface
namespace ConnectCx.Web.PluginUI.MVC5.Services.ServiceInterface
{
public interface IDefaultService
{
string DependancyStringTest();
}
}
is this an issue with my implimentation of Irepository? if not what is the issue here?
This error message tells you that Autofac is not able to build a DefaultService instance because the only available constructor require a IRepository<DependancyTestViewModel> and none is registered.
In order to fix this error you have to register a IRepository<DependancyTestViewModel>.
For example :
builder.RegisterType<DependancyTestViewModelRepository>()
.As<IRepository<DependancyTestViewModel>>();
or if you have a generic repository
builder.RegisterGeneric(typeof(GenericRepository<>))
.As(typeof(IRepository<>));
Related
I am trying to implement Dependency Injection with Autofac in an ASP.NET MVC5 Project. But I am getting the following error every time:
None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'MyProjectName.DAL.Repository` ........
My Autofac configuration code in App_Start folder as follows:
public static class IocConfigurator
{
public static void ConfigureDependencyInjection()
{
var builder = new ContainerBuilder();
builder.RegisterControllers(typeof(MvcApplication).Assembly);
builder.RegisterType<Repository<Student>>().As<IRepository<Student>>();
IContainer container = builder.Build();
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}
}
In Global.asax file:
public class MvcApplication : HttpApplication
{
protected void Application_Start()
{
// Other MVC setup
IocConfigurator.ConfigureDependencyInjection();
}
}
Here is my IRepository:
public interface IRepository<TEntity> where TEntity: class
{
IQueryable<TEntity> GelAllEntities();
TEntity GetById(object id);
void InsertEntity(TEntity entity);
void UpdateEntity(TEntity entity);
void DeleteEntity(object id);
void Save();
void Dispose();
}
Here is my Repository:
public class Repository<TEntity> : IRepository<TEntity>, IDisposable where TEntity : class
{
internal SchoolContext context;
internal DbSet<TEntity> dbSet;
public Repository(SchoolContext dbContext)
{
context = dbContext;
dbSet = context.Set<TEntity>();
}
.....................
}
Here is my Student Controller:
public class StudentController : Controller
{
private readonly IRepository<Student> _studentRepository;
public StudentController()
{
}
public StudentController(IRepository<Student> studentRepository)
{
this._studentRepository = studentRepository;
}
....................
}
What's wrong in my Autofac Configuration..Any Help Please??
To inject a dependency you need to have satisfied all of the dependencies for all of the pieces down the chain.
In your case, the Repository constructor cannot be satisfied without a SchoolContext.
So in your registration add:
builder.RegisterType<SchoolContext>().InstancePerRequest();
See http://docs.autofac.org/en/latest/lifetime/instance-scope.html#instance-per-request
I am trying to implement all sorts of good stuff like UnitOfWork, Repository, DI. I am using Unity for DI. Here is my dilemma. I have a few (currently 3) databases with identical schema but obviously with different data for business reasons (I will call them GroupDB1, GroupDB2 and GroupDB3). I also have a Master Database (DifferentDB) that has a different schema. My dbcontext need to use different databases for different scenarios at runtime. I have no clue how to put them all to work together.
Here is my dbContexts
public partial class GroupDB2 : DataContext
{
public GroupDB2() : base( "name=GroupDB2" )
{
}
public IDbSet<T> Set<T>() where T : EntityBase { return base.Set<T>(); }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//......
}
}
public partial class MasterDB : DataContext
{
public MasterDB() : base( "name=MasterDB" )
{
}
public IDbSet<T> Set<T>() where T : EntityBase { return base.Set<T>(); }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//......
}
}
and here are my other interfaces and implementations.
public class DataContext : DbContext, IDataContextAsync
{
private readonly Guid _instanceId;
bool _disposed;
public DataContext(string nameOrConnectionString) : base(nameOrConnectionString)
{
_instanceId = Guid.NewGuid();
//Configuration.LazyLoadingEnabled = false;
//Configuration.ProxyCreationEnabled = false;
}
}
public interface IDataContext : IDisposable
{
int SaveChanges();
}
public interface IDataContextAsync : IDataContext
{
Task<int> SaveChangesAsync(CancellationToken cancellationToken);
Task<int> SaveChangesAsync();
}
public interface IRepository<T> where T : class
{
IDataContextAsync Context { get; }
IDbSet<T> DbSet { get; }
void Add(T entity);
void Delete(T entity);
void Delete(dynamic id);
T FindOne(Expression<Func<T, bool>> predicate);
IQueryable<T> FindBy(Expression<Func<T, bool>> predicate);
IQueryable<T> GetAll();
void Update(T entity);
}
public interface IRepositoryAsync<TEntity> : IRepository<TEntity> where TEntity : class
{
Task<TEntity> FindAsync( params object[] keyValues );
Task<TEntity> FindAsync( CancellationToken cancellationToken, params object[] keyValues );
Task<bool> DeleteAsync( params object[] keyValues );
Task<bool> DeleteAsync( CancellationToken cancellationToken, params object[] keyValues );
}
public static IUnityContainer InitializeContainer( IUnityContainer _container )
{
container = _container;
....
....
container.RegisterType<IDataContextAsync, DataContext>( new InjectionConstructor( "name=MasterDB" ) );
container.RegisterType<IUnitOfWorkAsync, UnitOfWork>();// ("Async");
// Here is where I have no clue how do I register and resolve the correct entity context based on some conditions
// Like ConnectionStringService.GetConnectionString( for some condition );
//container.RegisterType<IDataContextAsync, DataContext>( "GroupDB", new InjectionConstructor( xxxxxx ) );
//container.RegisterType<IDataContextAsync, DataContext>( "DifferentDB", new InjectionConstructor( yyyyyy ) );
....
....
return container;
}
Since I read a lot about anti-patterns I am reluctant to do
var result = container.Resolve<MyObject>(
new ParameterOverride("x", ExpectedValue)
.OnType<MyOtherObject>());
I am stumped. Any help is highly appreciated. Thanks.
Babu.
I came up with an example that might be a bit over engineered, but I believe it gives you the most flexibility. You can see the entire example here. If you only want support for design time or only support for runtime, you can probably clean it up a bit.
For design time resolution, this uses an additional generics parameter as a token to identify the data store you wish to connect to. That allows you to resolve (via constructor injection) a unit of work and/or a repository that is specific to one data store.
MyService(IUnitOfWork<Group2Token> unitOfWork) { /* ... */ }
For runtime resolution, this uses a manager class to retrieve an instance of the desired unit of work with a string token.
MyService(IUnitOfWorkManager unitOfWorkManager)
{
_unitOfWork = unitOfWorkManager.GetUnitOfWork("Group2");
}
The managers use Unity's built-in support for resolving all named registrations into an array. More on that can be found in this question and answer.
Note that I suggest you use HierarchicalLifetimeManager for the registration of anything that's disposable. If you use that in combination with using child containers, you will have an automatic disposal mechanism. More info in this question and answer.
I have below code which will work without any issue
MAUserController.cs
public class MAUserController : ApiController
{
ILogService loggerService;
IMAUserService _service;
public MAUserController(ILogService loggerService, IMAUserService Service)
{
this.loggerService = loggerService;
this._service = Service;
}
}
DependencyInstaller.cs
public class DependencyInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(
Component.For<ILogService>().ImplementedBy<LogService>().LifeStyle.PerWebRequest,
Component.For<IDatabaseFactory>().ImplementedBy<DatabaseFactory>().LifeStyle.PerWebRequest,
Component.For<IUnitOfWork>().ImplementedBy<UnitOfWork>().LifeStyle.PerWebRequest,
AllTypes.FromThisAssembly().BasedOn<IHttpController>().LifestyleTransient(),
AllTypes.FromAssemblyNamed("ISOS.Health.Service").Where(type => type.Name.EndsWith("Service")).WithServiceAllInterfaces().LifestylePerWebRequest(),
AllTypes.FromAssemblyNamed("ISOS.Health.Repository").Where(type => type.Name.EndsWith("Repository")).WithServiceAllInterfaces().LifestylePerWebRequest()
);
}
}
If I am using normal Controller instead ApiController then it gives me an error
UserController.cs
public class UserController : Controller
{
ILogService loggerService;
IMAUserService _service;
public UserController(ILogService loggerService, IMAUserService Service)
{
this.loggerService = loggerService;
this._service = Service;
}
}
This will give an error:
No parameterless constructor defined for this object
I am using CastleDI Windsor for Dependency injection.
Do I need to do anything or register something?
FIRST APPROACH
Advice: Use with caution, because it may cause memory leaks for Castle Windsor.
You have to create a controller activator, which should implement the IControllerActivator interface, in order to use your DI container to create the controller instances:
public class MyWindsorControllerActivator : IControllerActivator
{
public MyWindsorControllerActivator(IWindsorContainer container)
{
_container = container;
}
private IWindsorContainer _container;
public IController Create(RequestContext requestContext, Type controllerType)
{
return _container.Resolve(controllerType) as IController;
}
}
Then, add this class to your DependencyInstaller:
public class DependencyInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(
// Current code...
Component.For<IControllerActivator>()
.ImplementedBy<MyWindsorControllerActivator>()
.DependsOn(Dependency.OnValue("container", container))
.LifestyleSingleton();
);
}
}
Also, create your own dependency resolver based on the Windsor container:
public class MyWindsorDependencyResolver : IDependencyResolver
{
public MyWindsorDependencyResolver(IWindsorContainer container)
{
_container = container;
}
private IWindsorContainer _container;
public object GetService(Type serviceType)
{
return _container.Resolve(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
return _container.ResolveAll(serviceType).Cast<object>();
}
}
Then, finally, register your dependency resolver in the Application_Start method in Global.asax.cs:
DependencyResolver.SetResolver(new MyWindsorDependencyResolver(windsorContainer));
This way, when MVC requires the controller activator through it's dependency resolver, it will get ours, which will use our Windsor container to create the controllers with all it's dependencies.
In order to avoid memory leaks using IControllerActivator, the easiest solution will be to use lifestyles like per thread or per web request, rather than the default (Singleton), transient and pooled, for the registered components. Check this link for more info about how to avoid memory leaks using Castle Windsor Container.
SECOND APPROACH
However, as pointed out by #PhilDegenhardt, a much better and correct approach will be to implement a custom controller factory, in order to be able to release the controller component created by the Castle Windsor DI Container. Here you can find an example (see the section about Dependency Injection).
Taken from that example, the implementation could be:
Global.asax.cs:
public class MvcApplication : System.Web.HttpApplication
{
private WindsorContainer _windsorContainer;
protected void Application_Start()
{
var _windsorContainer = new WindsorContainer();
_windsorContainer.Install(
new DependencyInstaller(),
// Other installers...
);
ControllerBuilder.Current.SetControllerFactory(new WindsorControllerFactory(_windsorContainer.Kernel));
}
protected void Application_End()
{
if (_windsorContainer != null)
{
_windsorContainer.Dispose();
}
}
}
WindsorControllerFactory.cs:
public class WindsorControllerFactory : DefaultControllerFactory
{
private readonly IKernel _kernel;
public WindsorControllerFactory(IKernel kernel)
{
_kernel = kernel;
}
public override void ReleaseController(IController controller)
{
_kernel.ReleaseComponent(controller); // The important part: release the component
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null)
{
throw new HttpException(404, string.Format("The controller for path '{0}' could not be found.", requestContext.HttpContext.Request.Path));
}
return (IController)_kernel.Resolve(controllerType);
}
}
Look at the following project link https://github.com/rarous/Castle.Windsor.Web.Mvc
Add this reference via NuGet to your MVC project, it will do the registering job for you.
Do not forget to catch your errors in global.asax.cs!
Registration :
container.Register(Component.For<IControllerFactory>().ImplementedBy<WindsorControllerFactory>());
Implementation of MVC controller factory :
using System;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
using Castle.MicroKernel;
namespace Installer.Mvc
{
public class WindsorControllerFactory : DefaultControllerFactory
{
private readonly IKernel _kernel;
public WindsorControllerFactory(IKernel kernel)
{
_kernel = kernel;
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null)
{
throw new HttpException(404, string.Format("The controller for path '{0}' could not be found.", requestContext.HttpContext.Request.Path));
}
if (_kernel.GetHandler(controllerType) != null)
{
return (IController)_kernel.Resolve(controllerType);
}
return base.GetControllerInstance(requestContext, controllerType);
}
public override void ReleaseController(IController controller)
{
_kernel.ReleaseComponent(controller);
}
}
}
I am having hard time using Repository patterns, is it possible to create two repository patterns?? One for products, another for orders??
I failed to connect these repositories to databases. I know how to work with one repository, but two with IRepository where T: Entity I am getting lost. The question is whether I can create and will not volatile the rules if create ProductRepository and OrderRepository?
Repository pattern is widely used in DDD (Domain-Driven-Design) you could check it here: http://www.infoq.com/minibooks/domain-driven-design-quickly. Also check this book: http://www.amazon.com/Domain-Driven-Design-Tackling-Complexity-Software/dp/0321125215
With regards to your question:
Yes you can use more than 1 repository. Look in this example I use nHibernate session:
// crud operations
public abstract class Repository<T> : IRepository<T> where T : class
{
protected readonly ISession _session;
public Repository(ISession session)
{
_session = session;
}
public T Add(T entity)
{
_session.BeginTransaction();
//_session.SaveOrUpdate(entity);
_session.Save(entity);
_session.Transaction.Commit();
return entity;
}
//...
}
public interface IRepository<T>
{
T Add(T entity);
T Update(T entity);
T SaveOrUpdate(T entity);
bool Delete(T entity);
}
Then my repository looks like this:
public class ProjectRepository : Repository<Project>, IProjectRepository
{
// Project specific operations
}
public interface IProjectRepository : IRepository<Project>
{
Project Add(Project entity);
Project Update(Project entity);
Project find_by_id(int id);
Project find_by_id_and_user(int id, int user_id);
//..
}
Then using Ninject:
Global.asax.cs
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterGlobalFilters(GlobalFilters.Filters);
RegisterRoutes(RouteTable.Routes);
ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory());
}
Then in NinjectControllerFactory I load the modules:
public class NinjectControllerFactory : DefaultControllerFactory
{
private IKernel kernel = new StandardKernel(new NhibernateModule(), new RepositoryModule(), new DomainServiceModule());
protected override IController GetControllerInstance(RequestContext context, Type controllerType)
{
//var bindings = kernel.GetBindings(typeof(IUserService));
if (controllerType == null)
return null;
return (IController)kernel.Get(controllerType);
}
}
NhibernateModule:
public class NhibernateModule : NinjectModule
{
public override void Load()
{
string connectionString =
ConfigurationManager.ConnectionStrings["sqlite_con"].ConnectionString;
var helper = new NHibernateHelper(connectionString);
Bind<ISessionFactory>().ToConstant(helper.SessionFactory).InSingletonScope();
Bind<ISession>().ToMethod(context => context.Kernel.Get<ISessionFactory>().OpenSession()).InRequestScope();
}
}
Then in RepositoryModule I use Ninject Conventions to automatically bind all repositories with their interfaces:
using Ninject.Extensions.Conventions;
public class RepositoryModule : NinjectModule
{
public override void Load()
{
IKernel ninjectKernel = this.Kernel;
ninjectKernel.Scan(kernel =>
{
kernel.FromAssemblyContaining<ProjectRepository>();
kernel.BindWithDefaultConventions();
kernel.AutoLoadModules();
kernel.InRequestScope();
});
}
}
And in the end I basically inject Repository in the controller:
public class projectscontroller : basecontroller
{
private readonly IProjectRepository _projectRepository;
public projectscontroller(IProjectRepository projectRepository)
{
_projectRepository = projectRepository;
}
[AcceptVerbs(HttpVerbs.Get)]
[Authorize]
public ActionResult my()
{
int user_id = (User as CustomPrincipal).user_id;
var projectList = _projectRepository.find_by_user_order_by_date(user_id);
var projetsModel = new ProjectListViewModel(projectList);
return View("my", projetsModel);
}
}
This way you just create new Repository and its Interface and it will be automatically injected to your controller.
I want to use Ninject in my project,this is my code :
public class NinjectControllerFactory : DefaultControllerFactory
{
private IKernel ninjectKernel;
public NinjectControllerFactory()
{
ninjectKernel = new StandardKernel();
AddBindings();
}
protected override IController GetControllerInstance(RequestContextrequestContext, Type controllerType)
{
return (controllerType == null) ? null :(IController)ninjectKernel.Get(controllerType);
}
private void AddBindings()
{
ninjectKernel.Bind<IHomeService>().To<HomeService>();
ninjectKernel.Bind<IHomeBussiness>().To<HomeBussiness>();
}
}
and my global.asax is :
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory());
and my home controller is:
private readonly IHomeService _iHomeService;
public HomeController(IHomeService iHomeService)
{
_iHomeService = iHomeService;
}
and now :
When I run My project I see that say Does not exist StandardProvider.cs
and my error is:
Error activating ObjectContext using implicit self-binding of ObjectContext
Several constructors have the same priority. Please specify the constructor using ToConstructor syntax or add an Inject attribute.
how can I Resolve this Issue?