Why can't I inject a dependancy into a ContentPage? - xaml

Please see the code below:
public partial class MyContentPage : ContentPage
{
public CreditCardView()
{
InitializeComponent();
}
}
It works as expected. Now say I want to inject a dependancy:
public partial class MyContentPage : ContentPage
{
private readonly IMyService _myService;
public CreditCardView(IMyService myService)
{
InitializeComponent();
_myService=myService;
}
}
With the second excerpt of code I see a compilation error: "The given key was not present in the dictionary". What is the problem? I have registered the dependancy.

Related

How to find all dependencies between two classes using VS Enterprise Code Map?

If I pull a class A and class B onto a Code Map, VSE (Visual Studio Enterprise) will map the direct calls of class A calling methods in class B.
So,
public class A
{
public void DoSomething()
{
b.DoSomethingElse();
}
}
This will map. But if it's something like:
public class A
{
public void DoSomething()
{
d.DoManyThings();
}
}
public class D
{
public void DoManyThings()
{
c.DoThings();
}
}
public class C
{
public void DoThings()
{
b.DoSomethingElse();
}
}
public class B
{
public void DoSomethingElse()
{
// imagine code here
}
}
Then the Code Map won't map between class A and class B automatically. The only way I've found to show those dependencies is to go to each method and click "Show Methods This Calls".
Is there a way to get VSE make the Code Map all those dependencies initially without having to investigate every method?

Asp.Net Core No service for type has been registered

I have the following two classes
public class RepositoryConnection : IRepositoryConnection{
public RepositoryConnection(IConfiguration configuration, ILogger<RepositoryConnection> logger){
//STUFF
}
}
public class AuthenticationTokenFactory : IAuthenticationTokenFactory {
public AuthenticationTokenFactory(ILogger<AuthenticationTokenFactory> logger) {
//STUFF
}
}
Here is my Startup.cs
public class Startup {
public Startup(IConfiguration configuration) {
Configuration = configuration;
}
public void ConfigureServices(IServiceCollection services) {
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
services.AddSingleton<IAuthenticationTokenFactory, AuthenticationTokenFactory>();
services.AddSingleton<IRepositoryConnection,RepositoryConnection>();
}
}
I can successfully inject IAuthenticationTokenFactory to controllers but when i try to inject IRepositoryConnection i get the following error→
InvalidOperationException: No service for type 'TrainingCommerce.Accessors.RepositoryConnection' has been registered.
Thanks to comments i immediately noticed my wrongful ways.
I was trying to access at another line
var debug = ControllerContext.HttpContext.RequestServices.GetRequiredService<RepositoryConnection>();
Try injecting the interface instead of the implementation:
In your sample you inject ILogger<RepositoryConnection> logger this is a typo and should be: ILogger<IRepositoryConnection> logger.
So:
public class RepositoryConnection : IRepositoryConnection{
public RepositoryConnection(IConfiguration configuration, ILogger<IRepositoryConnection> logger){
//STUFF
}
}

Castle windsor wire generic irepository with 2 types

Hi I am trying to change a code example found here
http://imar.spaanjaars.com/577/aspnet-n-layered-applications-implementing-a-repository-using-ef-code-first-part-5
In his example he uses structure map, when I converted it to windsor I can get it to work with the one repository using the following.
container.Register(Component.For<IUnitOfWorkFactory>().ImplementedBy<EFUnitOfWorkFactory>(),
Component.For<IUnitOfWork>().ImplementedBy<EFUnitOfWork>(),
Component.For<Model.Repositories.IPeopleRepository>().ImplementedBy<PeopleRepository>().LifestyleTransient());
But what I really want to do is to map all the irepository based interfacees to thier implementation.
Here is the IRepository, T is the entity, K is the prmiary key type
public interface IRepository<T, K> where T : class
{
}
Its implementation Is
public abstract class Repository<T> : IRepository<T, int>, IDisposable where T : DomainEntity<int>
{
}
My controller has the interface IPeopleRepository as a constructor paramerter.
public interface IPeopleRepository : IRepository<Person, int>
{
}
public class PeopleRepository : Repository<Person>, IPeopleRepository
{
}
I want to have one register to register all repositories, something like this, but it wont match and i get the error Service 'Spaanjaars.ContactManager45.Model.Repositories.IPeopleRepository' which was not registered
container.Register(Component.For(typeof(IRepository<,>))
.ImplementedBy(typeof(Repository<>))
.LifestylePerWebRequest());
What am i missing in regards to this? is it because my irepository has 2 generic types?
In order to map all the IRepository based interfaces to their implementations .WithService.AllInterfaces() should be used.
This registration should solve your issue.
container.Register(
Classes.FromThisAssembly()
.BasedOn(typeof(IRepository<,>))
.WithService.AllInterfaces()
.LifestylePerWebRequest());
There are some tests to test it. I claim they are green.
[TestClass]
public class InstallerTest
{
private IWindsorContainer container;
[TestInitialize]
public void Init()
{
container = new WindsorContainer().Install(new Installer());
}
[TestMethod]
public void ResilveTest_ResolvesViaIRepository()
{
// act
var repository = container.Resolve<IRepository<Person, int>>();
// assert
repository.Should().BeOfType<PeopleRepository>();
}
[TestMethod]
public void ResilveTest_ResolvesViaIPeopleRepository()
{
// act
var repository = container.Resolve<IPeopleRepository>();
// assert
repository.Should().BeOfType<PeopleRepository>();
}
}
public class Installer : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(
Classes.FromThisAssembly()
.BasedOn(typeof(IRepository<,>))
.WithService.AllInterfaces()
.LifestylePerThread());
}
}

Ninject: How to resolve collection from object type

Just wanted to know if there is a way bind a type and resolve a collection. I dont know if Ninject can do this out of the box. I'm using MVC4 with Ninject3 so I have the NinjectWebCommon.cs where I register the services. There is nowhere I can get the kernel (I read that it was bad practice to access the kernel from elsewhere, but that can certainly be the solution to this).
For example, I'm having this class:
public class CacheManager
{
public IEnumerable<SelectListItem> Get<T>() where T : INameValue
I want to be able to send
CacheManager.Get<City>
and obtain the CityRepository class.
Is it this you want to do? :
using System.Collections.Generic;
using System.Linq;
using Ninject;
using Ninject.Modules;
using Ninject.Syntax;
public class Temp
{
public interface ICity { }
public class SelectListItem
{
}
public class FooCity : SelectListItem, ICity { }
public class BarCity : SelectListItem, ICity {}
public class CityModule : NinjectModule
{
public override void Load()
{
this.Bind<ICity>().To<FooCity>();
this.Bind<ICity>().To<BarCity>();
}
}
public class CacheManager
{
private readonly IResolutionRoot resolutionRoot;
public CacheManager(IResolutionRoot resolutionRoot)
{
this.resolutionRoot = resolutionRoot;
}
public IEnumerable<SelectListItem> Get<T>()
{
return this.resolutionRoot.GetAll<T>().OfType<SelectListItem>();
}
}
}
I'm unclear as to whether you have multiple implementations of T (ICity) or one implementation but several instances (like retrieving a list of city names from the database and creating one instance per name). The later you could solve by a this.Bind>().ToProvider(...) binding.
I ended up doing:
In NinjectWebCommon.cs:
kernel.Bind(typeof(CacheManager))
.ToSelf()
.InSingletonScope();
kernel.Bind<IDataListRepository<Locale>>()
.To<LocaleRepository>();
In CacheManager.cs:
public class CacheManager: IDisposable
{
private IKernel kernel;
public CacheManager(IKernel kernel)
{
this.kernel = kernel;
}
public IEnumerable<T> GetAsEnumerable<T>()
{
var rep = kernel.Get<IDataListRepository<T>>();
return rep.GetAll();
}
I don't know if this is bad-practice (since kernel in theory should only be used in the initialization phase), but I didn't find any other way to do it.
If better options exist, please let me know.

Injecting my UnitOfWork into my Repository Constructor

Im very new but on a quest to learn nhibernate and DI with structuremap so am making an app to test everything out.
I am having some problems injecting my unitofwork into my base repository. I create a unitofwork on every request then either commit or rollback at the end. But when tryin to inject into my base repository its always null when i go to use it in my methods. More specifically i get this error: "Object reference not set to an instance of an object". Any ideas what im doing wrong and if this is the correct route i should be going?
Many thanks in advance.
Base Repository:
public abstract class Repository<T> : IRepository<T>
{
public readonly IUnitOfWork _unitOfWork;
public Repository(IUnitOfWork UnitOfWork)
{
UnitOfWork = _unitOfWork;
}
public Repository() {}
public void Save(T obj)
{
_unitOfWork.CurrentSession.Save(obj);
}
}
StructureMap registry thats set in my application_start:
public class NHibernateRegistry : Registry
{
public NHibernateRegistry()
{
For<IUnitOfWork>().HybridHttpOrThreadLocalScoped().Use<UnitOfWork>();
For<ISession>().HybridHttpOrThreadLocalScoped().Use(context => context.GetInstance<ISessionFactory>().OpenSession());
For<ISessionFactory>().Singleton().Use(NHibernateSessionFactory.GetSessionFactory());
}
}
Update:
The baserepository is inherited by specific repositorys ie ArticleRepository then im injecting that into my aspx pages on application_start. Then my aspx page inherits a basepage where the buildUp takes place. And i access the repository like this:
public IArticleRepository ArticleRepo { get; set; }
public void SaveThing()
{
ArticleRepo.Save(object);
}
This gets called on application_start:
public class Bootstrapper
{
public static void BootStrap()
{
ObjectFactory.Configure(x =>
{
x.AddRegistry<NHibernateRegistry>();
x.AddRegistry<WebRegistry>();
});
}
}
And in the webregistry:
For<IArticleRepository>().Use<ArticleRepository>();
There is a good chance your ArticleRepository doesn't have a constructor that takes an IUnitOfWork as a parameter make sure you have the following
public class ArticleRepository : Repository<Article>
{
public ArticleRepository(IUnitOfWork unitOfWork) : base(unitOfWork)
{
}
...
}
Remember Strcuture map uses the greediest constructor on the class that it instantiates. Since your abstract repository class will never be instantiated it will not use its constructors. I would also suggest not having any default constructors if your classes need to have their dependencies injected that way. Less chance for errors that way.
public readonly IUnitOfWork _unitOfWork;
public Repository(IUnitOfWork UnitOfWork)
{
UnitOfWork = _unitOfWork;
}
I think you mean to write
public readonly IUnitOfWork _unitOfWork;
public Repository(IUnitOfWork UnitOfWork)
{
_unitOfWork = UnitOfWork;
}
You were assigning the local variable to the parameter instead of the parameter to the local variable.
Edit: Also you should write your parameter with a lowercase U 'unitOfWork' instead of 'UnitOfWork'