I have this code:
public class TestDbContext : DbContext
{
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
if (!optionsBuilder.IsConfigured)
{
optionsBuilder.UseSqlServer(#"Server=(local);Database=MyDb;Trusted_Connection=True;");
}
}
}
Based on the description, this will be fired on new instance of TestDbContext. I have code that creates a new context:
TestDbContext ctx = new TestDbContext();
I was expecting OnConfiguring will be fired so I can set my connection string but code does not pass through here (I have breakpoint). Do I need anything else to setup.
My DI leading to the OnConfiguring(..) not firing also.
For me, I was able to add a ctor to resolve the issue
protected MyDbContext(DbContextOptions options) : base(options)
{
}
or if you'd prefer..
protected MyDbContext() : base(new DbContextOptions<MyDbContext>())
{
}
Related
I am new to xUnit and with the help of Prism Template Studio I created new Prism xUnit test project, which by default created one PrismAppMock.cs file as below:
// This should implement your application class -- What does it means?
public class PrismAppMock : PrismApplicationBase
{
public PrismAppMock(IPlatformInitializer initializer)
: base(initializer)
{
}
protected override IContainerExtension CreateContainerExtension()
{
return null;
}
protected override void OnInitialized()
{
}
protected override void RegisterTypes(IContainerRegistry containerRegistry)
{
}
}
On running the test it is throwing null exception as container is not resolved.
I tried to use UnityContainerExtension but as it is abstract class I can't use it directly.
protected override IContainerExtension CreateContainerExtension()
{
return new UnityContainerExtension();
}
Can anybody suggest on how to initialise PrismAppMock for unit testing.
I am building an ASP.net WebApi, and trying to use Entity alongside. I am following this guide.
Getting Started with ASP.NET Web API 2 (C#)
I am receiving a 500 internal server error using Fiddler. The JSON Exception message states ExceptionMessage=An error occurred when trying to create a controller of type 'LocationsController'. Make sure that the controller has a parameterless public constructor.
Here is the Controller.cs
[RoutePrefix("api/Locations")]
public class LocationsController : ApiController
{
// GET api/<controller>
private IlocationsRepository LocationsRepo;
public LocationsController(IlocationsRepository _repo)
{
if (_repo == null) { throw new ArgumentNullException("_repo"); }
LocationsRepo = _repo;
}
[HttpGet]
[Route("")]
public IEnumerable<Location> GetAll()
{
return LocationsRepo.GetAll();
}
}
I can't use a parameterless public constructor because I need to use the Database Repository that was created for Locations. I verified the issue was with the IlocationsRepository by doing the following.
When I replace the LocationsController constructor with no parameters , and declare a List<Location> within the controller, and use dummy data. I receive a 200 with all the json data correct.
Here is the start of the Global.asax.cs file
public class Global : System.Web.HttpApplication
{
protected void Application_Start(object sender, EventArgs e)
{
GlobalConfiguration.Configure(WebApiConfig.Register);
}
protected void Session_Start(object sender, EventArgs e)
{
}
}
It seems as if I need to do the dependency injection in the Global, but none of the guides had any information regarding this part.
For posterity here is the ContextDB cs
public class WebServerContext : DbContext
{
public WebServerContext() : base("WebServerContext") {}
public DbSet<Order> dOrders { get; set; }
public DbSet<Location> dLocations { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
}
For additional posterity, here is the Locations Repository.
public class LocationsRepository : IlocationsRepository
{
private z_Data.WebServerContext db = new z_Data.WebServerContext();
public void Add(Location item)
{
db.dLocations.Add(item);
}
public IEnumerable<Location> GetAll()
{
return db.dLocations;
}
}
As per Dependency Injection for Web Api tutorial on MSDN, you are missing the line to register the dependency resolver (a concrete class that implements System.Web.Http.IDependencyResolver) with Web Api. It acts like a bridge between your DI container and Web Api so it can resolve your constructor dependencies.
public static void Register(HttpConfiguration config)
{
var container = new UnityContainer();
container.RegisterType<IProductRepository, ProductRepository>(new HierarchicalLifetimeManager());
config.DependencyResolver = new UnityResolver(container); // <- You need this
// Other Web API configuration not shown.
}
Of course, that assumes you are using Unity. If not, you should either use the DependencyResolver that came with your DI container or implement your own.
NOTE: With some DI containers, you also need to register all of your controllers explicitly.
I am implementing dependency injection using Unity and the Unity.Webforms bootstrapper. I have a DbFactory in my webforms application which initializes my DbContext, and I am wanting to create one instance of this factory per web request, so that my various services will update under the same unit of work.
My question is, does the Unity.Webforms bootstrapper take care of this for me? I believe the answer in this post is suggesting doing the following in order accomplish a single context per request.
container.RegisterType<IDbFactory,DbFactory>(new HierarchicalLifetimeManager());
Is this correct, and is it all I need to do? I'm worried that it is creating a single context per request, but that it is an application wide context (all users sharing the same context).
This probably isn't necessary, but just in case, here is the implementation code for my DbFactory.
public class DbFactory : Disposable, IDbFactory
{
MyDbContext dbContext;
public MyDbContext Init()
{
return dbContext ?? (dbContext = new MyDbContext());
}
protected override void DisposeCore()
{
if(dbContext != null)
{
dbContext.Dispose();
}
}
}
public class Disposable : IDisposable
{
private bool isDisposed;
~Disposable()
{
Dispose(false);
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
private void Dispose(bool disposing)
{
if(!isDisposed && disposing)
{
DisposeCore();
}
isDisposed = true;
}
protected virtual void DisposeCore(){}
}
I have WebForms project, and there I have WebApi controller.
How I can inject to controller constructor and to action filter constructor?
I have implemented IDependencyResolver and use it in Global.asax (GlobalConfiguration.Configuration.DependencyResolver), but it doesn't help:
on request controller says that there is no default constructor and filter on application start says that it does not contain a constructor that takes 0 arguments.
Moreover, i need singletone injection to action filter.
Thanks.
UPD
public class ScopeContainer : IDependencyScope
{
protected readonly IUnityContainer _container;
public ScopeContainer(IUnityContainer container)
{
_container = container;
}
public object GetService(Type serviceType)
{
return _container.IsRegistered(serviceType) ? _container.Resolve(serviceType) : null;
}
public IEnumerable<object> GetServices(Type serviceType)
{
return _container.IsRegistered(serviceType) ? _container.ResolveAll(serviceType) : new List<object>();
}
public void Dispose()
{
_container.Dispose();
}
}
public class IoCContainer : ScopeContainer, IDependencyResolver
{
public IoCContainer(IUnityContainer container) : base(container)
{
}
public IDependencyScope BeginScope()
{
var child = _container.CreateChildContainer();
return new ScopeContainer(child);
}
}
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
RegisterRoutes();
ConfigureApi(GlobalConfiguration.Configuration);
}
void ConfigureApi(HttpConfiguration config)
{
var unity = new UnityContainer();
unity.RegisterInstance<ILogger>(new Logger());
unity.RegisterType<IRepository, DbRepository>();
config.DependencyResolver = new IoCContainer(unity);
}
private static void RegisterRoutes()
{
RouteTable.Routes.MapHttpRoute("ServiceApi", "api/{controller}/{action}");
}
}
I think this may be the way you are registering your routes.
WebApi routes are registered in the default project examples via the GlobalConfiguration.Routes rather than the RouteTable.Routes which is used by MVC controllers. If the ApiController is being incorrectly loaded by the MVC routing method it won't find your dependency resolver.
Try modifying your code to this:
public class Global : HttpApplication
{
void Application_Start(object sender, EventArgs e)
{
RegisterRoutes(GlobalConfiguration.Configuration);
ConfigureApi(GlobalConfiguration.Configuration);
}
void ConfigureApi(HttpConfiguration config)
{
var unity = new UnityContainer();
unity.RegisterInstance<ILogger>(new Logger());
unity.RegisterType<IRepository, DbRepository>();
config.DependencyResolver = new IoCContainer(unity);
}
private static void RegisterRoutes(HttpConfiguration config)
{
config.Routes.MapHttpRoute("ServiceApi", "api/{controller}/{action}");
}
}
I was having the same issue, I was working on a project trying to help modernize an old web forms project by converting page by page to Web API / Angular and getting the plumbing just right to use Unity was key.
When I was tracing I noticed unity was trying to resolve the controller classes but not the types to inject into their constructors, so I registered my controllers and it all worked. See my example below
Config setup, register controller and dependency
void ConfigureApi(HttpConfiguration config)
{
var container = UnitySingleton.UnityContainer;
container.RegisterType<IDashboardManager, ExampleStuff>();
container.RegisterType<DashboardController>(new InjectionConstructor(container.Resolve<IDashboardManager>()));
config.DependencyResolver = new UnityIoCContainer(container);
}
And my controller example:
public class DashboardController : ApiController
{
private readonly IDashboardManager _dashboardManager;
public DashboardController(IDashboardManager dashboardManager)
{
_dashboardManager = dashboardManager;
}
public async Task<IEnumerable<string>> Get()
{
return await _dashboardManager.GetDatas();
}
}
This is how I got mine working. It was a little different than the article above.
I have the Global.asax like the code below:
public class MvcApplication : System.Web.HttpApplication
{
public static void RegisterRoutes(RouteCollection routes)
{
// ....
}
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
RegisterRoutes(RouteTable.Routes);
ControllerBuilder.Current.SetControllerFactory(typeof(IOCControllerFactory));
}
}
public class IOCControllerFactory : DefaultControllerFactory
{
private readonly IKernel kernel;
public IOCControllerFactory()
{
kernel = new StandardKernel(new NanocrmContainer());
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null)
return base.GetControllerInstance(requestContext, controllerType);
var controller = kernel.TryGet(controllerType) as IController;
if (controller == null)
return base.GetControllerInstance(requestContext, controllerType);
var standartController = controller as Controller;
if (standartController is IIoCController)
((IIoCController)standartController).SetIoc(kernel);
return standartController;
}
class NanocrmContainer : Ninject.Modules.NinjectModule
{
public override void Load()
{
// ...
Bind<DomainModel.Entities.db>().ToSelf().InRequestScope().WithConstructorArgument("connection", "Data Source=lims;Initial Catalog=nanocrm;Persist Security Info=True;User ID=***;Password=***");
}
}
}
In this case if somewhere it is the class, defined like:
public class UserRepository : IUserRepository
{
private db dataContext;
private IUserGroupRepository userGroupRepository;
public UserRepository(db dataContext, IUserGroupRepository userGroupRepository)
{
this.dataContext = dataContext;
this.userGroupRepository = userGroupRepository;
}
}
then the dataContext instance is created (if no one was created in this request scope) by Ninject.
So the trouble now is - where to invoke dataContext method .Dispose()?
UPD:
so i followed the advice from KeeperOfTheSoul and solved the issue in such way:
public override void ReleaseController(IController controller)
{
base.ReleaseController(controller);
var db = kernel.Get<DomainModel.Entities.db>();
db.Dispose();
}
A good place to handle this is in IControllerFactory.ReleaseController, eg
public override void ReleaseController() {
base.ReleaseController();
//Do whatever you need to clean up the IoC container here
}
In NInject this could be handled by scoping using an activation block, at the start of the request when creating the controller you can store the activation block in the HttpContext's current items, during ReleaseController you can retrieve the previously created activation block and dispose it.
You could also consider using InScope and having the custom scope implement INotifyWhenDisposed. After that the usage is the same as with an activation block, except now you store the scope in the HttpContext's current items.
A pattern that is sometimes used to dispose db connections is to call Dispose from the finaliser.
public class db : IDisposable {
//called by the garbage collector
~db() {
//Call dispose to make sure the resources are cleaned up
Dispose(false);
}
//IDisposable implementation
public void Dispose() {
Dispose(true);
}
//subclasses of db can override Dispose(bool) and clean up their own fields
protected virtual void Dispose (bool disposing) {
if (disposing) {
//Supress finalization as all resources are released by this method
//Calling Dispose on IDisposable members should be done here
GC.SupressFinalize();
}
//Clean up unmanaged resources
//Do not call other objects as they might be already collected if called from the finalizer
}
}
You could hook it into Application_EndRequest.