Question

In my global.asax file I have a dependency set up between an interface and a class. The injection always works and there is no issue with the setup.

In a model binder, in the same solution, I am trying to get the concrete class mapped to that interface thus

IKernel kernel = new StandardKernel();
var samurai = kernel.Get<Samurai>();

For some reason this does not work and I get an error saying “object initialisation null” or something to that effect. As I understand it this makes sense since this kernel I just created is a new object not linked to the object created in the global.asax. How do I get the one in the global.asax or am I doing something else wrong?

Answer 1

In global.asax.cs, I used static variable for this kind of situation.

protected override IKernel CreateKernel()
{
    return NinjectKernel;    
}

static IKernel _kernel;
public static IKernel NinjectKernel
{
  get
  {
      if (_kernel == null)
      {
         _kernel = new StandardKernel();
         //Configured bindings for interfaces and classes
      }
      return _kernel;
   }
}

And I think you are trying to get reference to interface i.e., ISamurai which inturn gives reference to actual object Samurai.

var samurai = NinjectKernel.Get<ISamurai>()