autofac instance a class in constructor - c#

I have the next problem, i dont understand why this code dont work i think is because i dont injectate the class of constructor by autofac but i dont know how do that, can us help me to do that the better way?
Before I add the generator this work if i comment the generator code in service work.
This is my code:
I have a class Controller that invoke a serv:
public class ZonesController : Controller
{
private IZoneService zoneService;
public ZonesController(IZoneService zoneService)
{
this.zoneService = zoneService;
}
[HttpGet]
//Do work
}
This is the service and interface:
public class ZoneService : IZoneService
{
private readonly IZoneRepository zoneRepository;
private readonly IDtoFactory dtoFactory;
private readonly ZoneGenerator zoneGenerator;
public ZoneService(IZoneRepository zoneRepository,
IDtoFactory dtoFactory,
ZoneGenerator zoneGenerator)
{
this.zoneRepository = zoneRepository;
this.dtoFactory = dtoFactory;
this.zoneGenerator = zoneGenerator;
}
public void Add(ZoneDetailDTO zone)
{
zoneGenerator.Generate(zone);
}
//Do Work
}
public interface IZoneService
{
void Add(ZoneDetailDTO zone);
//Do Methods
}
The generator invoke ohter class, factories:
public class ZoneGenerator
{
private readonly ZoneFactory zoneFactory;
private readonly IZoneRepository zoneRepository;
public ZoneGenerator(ZoneFactory zoneFactory, IZoneRepository zoneRepository)
{
this.zoneFactory = zoneFactory;
this.zoneRepository = zoneRepository;
}
public void Generate(ZoneDetailDTO zoneModel)
{
var zone = zoneFactory.Create(zoneModel);
zoneRepository.Add(zone);
}
}
The Factory:
public class ZoneFactory
{
private readonly ZoneMapFactory zoneMapFactory;
private readonly ZoneScheduleFactory zoneScheduleFactory;
public ZoneFactory(ZoneMapFactory zoneMapFactory,
ZoneScheduleFactory zoneScheduleFactory)
{
this.zoneMapFactory = zoneMapFactory;
this.zoneScheduleFactory = zoneScheduleFactory;
}
public Zone Create(zoneDetailDTO zone)
{
var map = zoneMapFactory.Create(zone.Map.Address, zone.Map.Latitude, zone.Map.Longitude);
var schedule = zoneScheduleFactory.Create(zone.Schedule.StartHour, zone.Schedule.EndHour);
return new Zone(zone.Name,
zone.ProvinceId,
map,
schedule,
zone.Tags);
}
}
And finally my container:
//method in Startup class Asp.Net Core
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddSingleton(_ => Configuration);
// Add framework services.
services.AddApplicationInsightsTelemetry(Configuration);
services.AddMvc();
var containerBuilder = new ContainerBuilder();
containerBuilder.RegisterModule<DefaultModule>();
containerBuilder.Populate(services);
var container = containerBuilder.Build();
return new AutofacServiceProvider(container);
}
public class DefaultModule : Module
{
protected override void Load(ContainerBuilder builder)
{
builder.RegisterType<ZoneService>().As<IZoneService>();
builder.RegisterType<ZoneRepository>().As<IZoneRepository>();
builder.RegisterType<ProvinceService>().As<IProvinceService>();
builder.RegisterType<ProvinceRepository>().As<IProvinceRepository>();
builder.RegisterType<DtoFactory>().As<IDtoFactory>();
}
}

You have missed to add to your Load method the following:
builder.RegisterType<ZoneGenerator>().AsSelf();
builder.RegisterType<ZoneFactory>().AsSelf();
builder.RegisterType<ZoneMapFactory>().AsSelf();
builder.RegisterType<ZoneScheduleFactory>().AsSelf();

Related

Dependency Injection in Xamarin.Android

I am working on a Xamarin.Android project developed by another developer. I got to know that they have used Dependancy Injection. There is a class like this
public class RemoteSupportHandler : DataAccessor<FwDataContext>, IRemoteSupportSettingHandler
{
private RemoteSupportSetting[] _cached;
public RemoteSupportHandler(IDatabaseController db, ILogger logger, IPerfLogger perfLogger)
: base(db, logger, perfLogger)
{
}
public async Task<RemoteSupportSetting> GetRemoteSupportDemoVideoUrlAsync()
{
return await WithDataContextAsync(ctx =>
{
return (from row in ctx.RemoteSupportSettings
where row.ParamName == "DEMO_VIDEO"
select new RemoteSupportSetting
{
ParamName = row.ParamName
}).FirstOrDefault();
});
}
}
In another file, they have registered this class with UnityContainer. Now I want to call this GetRemoteSupportDemoVideoUrlAsync() method from my Activity. I know I cannot create an object using this constructor. I have no idea how I should I do this.
Registration Code
public class Registrar : IRegistrar {
protected virtual void OnApplyInitializedRegistrations(IUnityContainer container) {
container.RegisterType<IRemoteSupportSettingHandler, RemoteSupportHandler>(new ContainerControlledLifetimeManager());
}
}
public interface IRegistrar
{
void ApplySessionRegistrations(IUnityContainer container);
void ApplyInitializedRegistrations(IUnityContainer container);
}
UPDATE 2
public abstract class MyApplication : Application, IPlatformApplication {
public IUnityContainer AppUnityContainer => _container;
protected virtual void OnLaunched()
{
IActivityService activityService = new ActivityService(this);
AppUnityContainer.RegisterInstance(activityService);
AppUnityContainer.RegisterType<IRegistrar, PlatformRegistrar>();
}
}

Inject Dependency into Core Module of a ASP Boilerplate project

I have NotificationJob class where I have all the functions related to Notification Feature for my .Net Core application. It has some injected dependencies from Domain services. I am having a problem trying to inject INotificationJob interface of the class into the CoreModule of the project.
I initially tried injecting the interface directly into the CoreModule but failed so I created another module in the same file called NotificationModule where I inject INotificationJob interface. Then I try to link it with the CoreModule using [DependsOn(typeof(oasisCoreModule))] annotation.
Core Module of the project
[DependsOn(
typeof(AbpZeroCoreModule),
typeof(AbpHangfireAspNetCoreModule),
typeof(AbpWebCommonModule)
)]
public class oasisCoreModule : AbpModule
{
public override void PreInitialize()
{
Configuration.Modules.AbpWebCommon().SendAllExceptionsToClients = true;
Configuration.BackgroundJobs.UseHangfire();
Configuration.Auditing.IsEnabledForAnonymousUsers = true;
// Declare entity types
Configuration.Modules.Zero().EntityTypes.Tenant = typeof(Tenant);
Configuration.Modules.Zero().EntityTypes.Role = typeof(Role);
Configuration.Modules.Zero().EntityTypes.User = typeof(User);
oasisLocalizationConfigurer.Configure(Configuration.Localization);
// Enable this line to create a multi-tenant application.
Configuration.MultiTenancy.IsEnabled = oasisConsts.MultiTenancyEnabled;
// Configure roles
AppRoleConfig.Configure(Configuration.Modules.Zero().RoleManagement);
Configuration.Settings.Providers.Add<AppSettingProvider>();
}
public override void Initialize()
{
IocManager.RegisterAssemblyByConvention(typeof(oasisCoreModule).GetAssembly());
}
public override void PostInitialize()
{
IocManager.Resolve<AppTimes>().StartupTime = Clock.Now;
}
}
// This is the custom module that I created in the same file as the core module.
[DependsOn(typeof(oasisCoreModule))]
public class NotificationModule : AbpModule
{
INotificationJob _job;
public NotificationModule(INotificationJob job)
{
_job = job;
}
public override void Initialize()
{
IocManager.RegisterAssemblyByConvention(Assembly.GetExecutingAssembly());
}
public override void PostInitialize()
{
_job.Loop();
}
}
INotificationJob Interface I am Injecting into the NotificationModule
public interface INotificationJob: IDomainService
{
void Loop();
void CheckTickets();
void CheckReminders(string email, string ticket);
}
Class Implementation of INotificationJob Interface
public class NotificationJob: DomainService, INotificationJob
{
private readonly ITicketRefManager _ticketRefManager;
private readonly IClientManager _clientManager;
private readonly IEmailManager _emailManager;
public NotificationJob(
ITicketRefManager ticketRefManager,
IClientManager clientManager,
IEmailManager emailManager,
)
{
_ticketRefManager = ticketRefManager;
_clientManager = clientManager;
_emailManager = emailManager;
}
public void Loop()
{
RecurringJob.AddOrUpdate(() => CheckTickets(), Cron.Minutely);
}
}
When I run the solution, I am presented with an error saying as shown:
Are there any other steps that I need to take to complete the Dependency Injection process? Or are the steps that I described flawed?
I'm not sure what you're trying to do with you "interface injecting", but you can try this if I understand correctly what you're trying to do :
Core Module
[...]
public override void PostInitialize()
{
var recurrentJobs = IocManager.Resolve<NotificationJob>();
RecurringJob.RemoveIfExists("JobName");
RecurringJob.AddOrUpdate("JobName", () => recurrentJobs.CheckTickets(), Cron.Minutely);
}
Your class
public class NotificationJob : ISingletonDependency
{
private readonly ITicketRefManager _ticketRefManager;
private readonly IClientManager _clientManager;
private readonly IEmailManager _emailManager;
public NotificationJob(
ITicketRefManager ticketRefManager,
IClientManager clientManager,
IEmailManager emailManager,
)
{
_ticketRefManager = ticketRefManager;
_clientManager = clientManager;
_emailManager = emailManager;
}
public void CheckTickets()
{
//Do something
}
}
Does it helps ?

Ninject: entity object cannot be referenced by multiple instances of IEntityChangeTracker

I am starting to use Ninject in my MVC5 code-first app. Here's my NinjectWebCommon.cs:
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<CMSContext>()
.ToSelf()
//.InSingletonScope();
.InRequestScope();
kernel.Bind<IExecutiveRepository>()
.To<ExecutiveRepository>();
kernel.Bind<IExecutiveSectionRepository>()
.To<ExecutiveSectionRepository>();
kernel.Bind<IExecutiveSectionMappingRepository>()
.To<ExecutiveSectionMappingRepository>();
kernel.Bind<IUserRepository>()
.To<UserRepository>();
kernel.Bind<IContentRepository>()
.To<ContentRepository>();
RegisterServices(kernel);
return kernel;
}
catch
{
kernel.Dispose();
throw;
}
}
I tried .InSingletonScope() as well as .InRequestScope() but I still get the 'entity object cannot be referenced by multiple instances of IEntityChangeTracker' error.
Here is my Interface:
public interface IExecutiveRepository : IDisposable
{
IEnumerable<Executive> GetExecutives();
Executive GetExecutiveById(int executiveId);
void InsertExecutive(Executive executive);
void UpdateExecutive(Executive executive);
void DeleteExecutive(int executiveId);
void Save();
}
Here is my concrete:
public class ExecutiveRepository : IExecutiveRepository, IDisposable
{
private CMSContext context;
public ExecutiveRepository(CMSContext context)
{
this.context = context;
}
public IEnumerable<Executive> GetExecutives()
{
return context.Executives.ToList();
}
public Executive GetExecutiveById(int id)
{
return context.Executives.Find(id);
}
public void InsertExecutive(Executive executive)
{
context.Executives.Add(executive);
}
public void DeleteExecutive(int executiveId)
{
Executive executive = context.Executives.Find(executiveId);
context.Executives.Remove(executive);
}
public void UpdateExecutive(Executive executive)
{
context.Entry(executive).State = EntityState.Modified;
}
public void Save()
{
context.SaveChanges();
}
private bool disposed = false;
protected virtual void Dispose(bool disposing)
{
if (!this.disposed)
{
if (disposing)
{
context.Dispose();
}
}
this.disposed = true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
Here is the controller(top pertinent part):
public class ExecutiveController : Controller
{
private IExecutiveRepository executiveRepository;
private IUserRepository userRepository;
private IExecutiveSectionRepository executiveSectionRepository;
private IExecutiveSectionMappingRepository executiveSectionMappingRepository;
private IContentRepository contentRepository;
private Ninject.IKernel _kernel = new StandardKernel();
//[Inject]
public ExecutiveController()
{
executiveRepository = _kernel.Get<ExecutiveRepository>();
userRepository = _kernel.Get<UserRepository>();
executiveSectionRepository = _kernel.Get<ExecutiveSectionRepository>();
executiveSectionMappingRepository = _kernel.Get<ExecutiveSectionMappingRepository>();
contentRepository = _kernel.Get<ContentRepository>();
}
...
Not sure what I am doing wrong but upon adding a new 'Executive' it bombs... I do understand it's trying to use separate contexts and that's the problem, but I 'm just not sure how to fix it. Apparently, the line in the NinjectWebCommon.cs class:
kernel.Bind<CMSContext>()
.ToSelf()
//.InSingletonScope();
.InRequestScope();
Is supposed to be the fix, but it isn't...
any ideas/suggestions?
You should be using NUGET package Ninject.Web.Mvc if you aren't already. This configures your application ready to use Ninject, other than your bindings. It looks like you are reasonably familiar with the bindings side of things already from what I can see in your CreateKernel() method.
Once your bindings are in place, you should not be creating Kernels in your controllers, this is because the Ninject.Web.Mvc library configures Ninject to create your controllers for you under the hood. Therefore any dependencies that you add to them should be automatically resolved.
So, you can use constructor injection to resolve your dependencies:
public class ExecutiveController : Controller
{
private IExecutiveRepository ExecutiveRepository;
private IUserRepository UserRepository;
private IExecutiveSectionRepository ExecutiveSectionRepository;
private IExecutiveSectionMappingRepository ExecutiveSectionMappingRepository;
private IContentRepository ContentRepository;
public ExecutiveController(
IExecutiveRepository executiveRepository,
IUserRepository userRepository,
IExecutiveSectionRepository executiveSectionRepository,
IExecutiveSectionMappingRepository executiveSectionMappingRepository,
IContentRepository contentRepository)
{
// Set the field values
this.ExecutiveRepository = executiveRepository,
this.UserRepository = userRepository,
this.ExecutiveSectionRepository = executiveSectionRepository,
this.ExecutiveSectionMappingRepository = executiveSectionMappingRepository,
this.ContentRepository = contentRepository;
}
public ActionResult Index(int id)
{
// Use one of your dependencies...
var executive = this.executiveRepository.GetExecutiveById(id);
}
}
Or you can use the [Inject] attribute which has the same effect:
public class ExecutiveController : Controller
{
[Inject]
public IExecutiveRepository executiveRepository { get; set; }
[Inject]
public IUserRepository userRepository { get; set; }
[Inject]
public IExecutiveSectionRepository executiveSectionRepository { get; set; }
[Inject]
public IExecutiveSectionMappingRepository executiveSectionMappingRepository { get; set; }
[Inject]
public IContentRepository contentRepository { get; set; }
public ExecutiveController()
{
}
public ActionResult Index(int id)
{
// Use one of your dependencies...
var executive = this.executiveRepository.GetExecutiveById(id);
}
}
You're creating a kernel per controller.
InRequestScope only ensures one instance per request per kernel.
So you need to adapt your setup of the kernel so there's only one kernel per web application. See:
Ninject.Web.Mvc
Tutorial
Youtube
This may not answer the question. But I tend to use the IDbContextFactory that EF provides you with and do something like this:
public interface IDefaultContextFactory : IDbContextFactory<CMSContext> {}
public class DefaultContextFactory : IDefaultContextFactory
{
private readonly Lazy<CMSContext> lazyContext = new Lazy<CMSContext>(() => new CMSContext());
public CMSContext Create()
{
return lazyContext.Value;
}
}
Then you just bind that, and when you need the context you can do something like this:
public class ExecutiveRepository : IExecutiveRepository, IDisposable
{
private readonly CMSContext context;
public ExecutiveRepository(IDefaultContextFactory contextFactory)
{
this.context = contextFactory.Create();
}
}
I believe #BatteryBackupUnit is correct, I would also consider using the above pattern for contexts.

How do I use Autofac instead singleton in c#?

I have used singleton pattern a using static property, constructor
public class MyClass
{
private readonly MemoryCacheManager _cacheManager;
private static readonly Lazy<MyClass> _Lazy = new Lazy<MyClass>(() => new MyClass());
public static MyClass Language { get { return _Lazy.Value; } }
private MyClass()
{
_cacheManager = new MemoryCacheManager();
LoadCacheData();
}
// Rest of class
}
I have tried like following using Autofac in global.asax:
protected void Application_Start()
{
var builder = new ContainerBuilder();
builder.RegisterType<MemoryCacheManager>().SingleInstance();
}
And inside MyClass constructor:
private MyClass(MemoryCacheManager cache)
{
_cacheManager = cache;
LoadCacheData();
}
public string Translate(string language)
{
var translation = _cacheManager.GetValueFromCache();
}
And I want to call this method in Index.cshtml
Previously I did it directly like this:
<h4>#MyClass.Language.Translate("Welcome", Model.Language)</h4>
As I had Language as follow in MyClass:
public static Localizer Language { get { return _Lazy.Value; } }
But now I do not have this property.
How can I call Translate method in Index.cshtml as I do not have static property like previous.
You just need to register MyClass as a SingleInstance with your container:
var builder = new ContainerBuilder();
builder.RegisterType<MyClass>().As<IMyClass>().SingleInstance();
Then inject where ever you need:
public AnotherClass(IMyClass myClass)
{
_myClass = myClass;
}
Although it's probably the cache you want a single instance of. In that case:
builder.RegisterType<MemoryCacheManager>().SingleInstance();
And then:
public MyClass(MemoryCacheManager cache)
{
_cacheManager = cache;
LoadCacheData();
}
EDIT:
The first thing you need to do is set the DependencyResolver in your Application_Start class (you'll need to get the Autofac MVC Integration NuGet package for this):
protected void Application_Start()
{
this.RegisterAutoFac();
// Rest of method
}
private void RegisterAutoFac()
{
var builder = new ContainerBuilder();
builder.RegisterControllers(typeof(MvcApplication).Assembly);
builder.RegisterType<MyClass>().As<IMyClass>();
builder.RegisterType<MyCache>().As<IMyCache>().SingleInstance();
var container = builder.Build();
// Setup the dependency resolver
DependencyResolver.SetResolver(new AutofacDependencyResolver(container));
}
Then you need to inject MyClass into the constructor of your controller:
public class TestController : Controller
{
private readonly IMyClass _myClass;
public TestController(IMyClass myClass)
{
_myClass = myClass;
}
// Rest of the controller
}
Then when your creating model for you get the data you need from MyClass:
public ActionResult Index()
{
var model = new ExampleModel
{
WelcomeMessage = _myClass.Translate("Welcome")
};
return View(model);
}
And in your view:
<h4>#Model.WelcomeMessage</h4>

Using Autofac with Dynamic Proxy that output message automatic

public interface ILog
{
void Write(string msg);
}
public class MyLog : ILog
{
public void Write(string msg)
{
Console.WriteLine(msg);
}
}
public interface ICanLog
{
ILog Log { get; set; }
}
public interface IMyClass
{
void Test();
}
public class MyClass : IMyClass, ICanLog
{
public ILog Log { get; set; }
public void Test()
{
Log.Write("Test");
}
}
I am using Autofac with Castle DynamicProxy,
and try to let MyClass Test Method output "BEGIN"/"END" automatic.
public class MyLogInterceptor : IInterceptor
{
public void Intercept(IInvocation invocation)
{
Console.WriteLine("BEGIN");
invocation.Proceed();
Console.WriteLine("END");
}
}
The following is test code:
ContainerBuilder builder = new ContainerBuilder();
builder.RegisterType<MyLog>().As<ILog>();
builder.Register(c =>
{
ProxyGenerator g = new ProxyGenerator();
object proxy = g.CreateClassProxy(typeof(MyClass), new MyLogInterceptor());
ICanLog proxyICanLog = (ICanLog)proxy;
proxyICanLog.Log = c.Resolve<ILog>();
return proxy;
}).As<IMyClass>();
using (var container = builder.Build())
{
objectContext.Container = container;
IMyClass myclass = container.Resolve<IMyClass>();
myclass.Test();
}
But result no output "BEGIN"/"END", why ?
and if I create AutoLogModule that try build Log Property Instance automatic
public class AutoLogModule : Autofac.Module
{
protected override void AttachToComponentRegistration(IComponentRegistry componentRegistry, IComponentRegistration registration)
{
var type = registration.Activator.LimitType;
if (HasPropertyDependencyOnClass(type))
{
registration.Activated += InjectClassViaProperty;
}
}
private bool HasPropertyDependencyOnClass(Type type)
{
return type.GetProperties().Any(property => property.CanWrite && property.PropertyType==typeof(ILog));
}
private void InjectClassViaProperty(object sender, ActivatedEventArgs<object> evt)
{
var type = evt.Instance.GetType();
var propertyInfo = type.GetProperties().First(x => x.CanWrite && x.PropertyType==typeof(ILog));
ILog log = new MyLog();
propertyInfo.SetValue(evt.Instance, log, null);
}
}
The following is test code:
ContainerBuilder builder = new ContainerBuilder();
builder.RegisterType<MyLog>().As<ILog>();
builder.RegisterModule(new AutoLogModule());
builder.Register(c =>
{
ProxyGenerator g = new ProxyGenerator();
object proxy = g.CreateClassProxy(typeof(MyClass), new MyLogInterceptor());
//ICanLog proxyICanLog = (ICanLog)proxy;
//proxyICanLog.Log = c.Resolve<ILog>();
return proxy;
}).As<IMyClass>();
using (var container = builder.Build())
{
objectContext.Container = container;
IMyClass myclass = container.Resolve<IMyClass>();
myclass.Test();
}
The result is Test Method throw
"Object reference not set to an instance of an object."
in Log.Write("Test")
How to write this feature?
I know this is a rather old post but as I was trying to accomplish the same thing with Autofac and I found the documentation that helped me to achieve it. I will answer just in case it helps someone else.
In my case I'm using Autofac 4.92 and and extra package for DynamicProxy called Autofac.Extras.DynamicProxy 4.5.0 as the documentations sates.
I see a difference where you register your Interceptors. Even though what you are doing is what I would have done initially; is not what Autofac Documentation currently says about how to Register Interceptors:
builder.RegisterType<MyClass>().As<IMyClass>().EnableInterfaceInterceptors();
// Typed registration
builder.Register(c => new MyLogInterceptor ();
Lastly, you need to Associate Interceptors with Types to be Intercepted:
[Intercept(typeof(MyLogInterceptor))]
public class MyClass : IMyClass, ICanLog
{
public ILog Log { get; set; }
public void Test()
{
Log.Write("Test");
}
}
I hope this answer may help. In any case, the Autofac documentation explains step by step how to do it just in case my code may mistakenly skip some relevant part.

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