Ninject property injection not working

Question

I am new in Ninject and I need some help to move on.

I have a solution that consists of web.form (presentation) and various other class libraries projects.

In web.form application inside NinjectWebCommon cs file I have the following

kernel.Bind<HttpContext>()
      .ToMethod(ctx => HttpContext.Current).InThreadScope();

kernel.Bind<HttpContextBase>()
      .ToMethod(ctx => new HttpContextWrapper(HttpContext.Current)).InTransientScope();

kernel.Bind<MPIBE.DESTINATION.CORE.SiteContext>()
      .ToMethod(ctx => new MPIBE.DESTINATION.CORE.SiteContext(
                           new HttpContextWrapper(HttpContext.Current)
       ));

I am trying to get an instance of a class (following the constructor)

public SessionUtilities(SiteContext siteContext)
{
    _siteContext = siteContext;
}

and I noticed that i can get the instance only form web.forms application and I can't get from other projects (class libraries). Does this make any sense?

I am trying to get the instance via property injection

[Inject]
public SessionUtilities _sessionUtilities { get; set; }

score 12 · Accepted Answer · answered Oct 01 '13 at 16:43

12

I suspect the class that contains your _sessionUtilities property is being created with new instead of via Ninject.

Ninject will only inject your _sessionUtilities property if the containing instance is also created by Ninject, either because it is created with kernel.Get() or because it is itself being injected.

answered Oct 01 '13 at 16:43

shamp00

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The instance is created via property injection as shown above and not by using the "new". – profanis Oct 02 '13 at 07:17
I'm talking about the instance of _the containing class_. The class which contains the `_sessionUtilities` property. How is that created? – shamp00 Oct 02 '13 at 07:45
This class instantiated via new... so, this class needs to instantiated with ninject as well? – profanis Oct 02 '13 at 10:50
3

Yes! Dependency injection is [turtles all the way down](https://en.wikipedia.org/wiki/Turtles_all_the_way_down). – shamp00 Oct 02 '13 at 13:53
@shamp00 That's useful information. Is there a way to get an instance of a Kernel in a non Ninject created instance? I'm trying to inject into a colleagues class in a referenced project which has no access to the current Kernel. – Ian May 30 '14 at 16:27
Yes @Ian, it's possible via a static `ServiceLocator`, such as the one described in [this article](http://kohari.org/2008/06/18/playing-nice-with-service-locators/). However, [a service locator is considered a code smell](http://blog.ploeh.dk/2010/02/03/ServiceLocatorisanAnti-Pattern/), since your code is then tightly coupled to the service locator. It would be better to pass a `SessionUtilitiesProvider` class instead. – shamp00 Jun 02 '14 at 09:22
@shamp00: I've actually asked a question about this http://stackoverflow.com/questions/23989946/dependency-injection-into-referenced-project if you'd be up for providing an answer with a brief example of the SessionUtlitiesProvider? – Ian Jun 02 '14 at 09:25

Ninject property injection not working

1 Answers1