C# – NInject: Where do you keep your reference to the Kernel

c++dependency-injectioninversion-of-controlioc-containerninject

I'm using NInject on a new web application and there are two things that are unclear to me:

  1. Don't I need to keep a reference to the Kernel around (Session/App variable) to insure that GC doesn't collect all my instances? For example, if I specify .Using() and then the Kernel object gets collected, aren't all my "singletons" collected as well?

  2. If I do need keep a reference to a Kernel object around, how do I allow the arguments passed in to WithArguments() to change or is that not possible.

Best Solution

It's true that you don't want to pass around the kernel. Typically, in a web app, I store the kernel in a static property in the HttpApplication. If you need a reference to the kernel, you can just expose a dependency (via constructor argument or property) that is of the type IKernel, and Ninject will give you a reference to the kernel that activated the type.

If you use WithArguments() on a binding, they will be used for all activations. If you use IParameters, they will only be used for that activation. (However, if the service you're activating has a re-usable behavior like Singleton, it won't be re-activated even if you pass different IParameters.)

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