Question

I have this code :

abstract class GenericAbstractClass<T> where T : struct { }

class ImplementationClass : GenericAbstractClass<int> { }

class Program {
    static void Main (string[] args)
    {
        IKernel kernel = new StandardKernel();
            kernel.Bind(typeof(GenericAbstractClass<>)).To(typeof(ImplementationClass));

            var classes = kernel.GetAll(typeof(GenericAbstractClass<>));
            Console.WriteLine(classes.Count()); // Print 2.

            foreach (var cls in classes) {
                if (cls is ImplementationClass)
                    Console.WriteLine("cls is ImplementationClass");
            }


            Console.ReadLine();
        }
    }

The output is :

2
cls is ImplementationClass
cls is ImplementationClass

I expect classes.Count() result is 1.

Why GetAll return duplicate object despite of I only bind GenericClass to ImplementationClass ?

What should I do to make GetAll return all non-duplicate object?

P.S. I use ninject 2.2

Answer 1

Your binding does not make any sense. You are binding an open generic type to a closed one. It seems that there is a gap in Ninject’s plausibility check for bindings.

Change the binding to

kernel.Bind(typeof(GenericAbstractClass<int>)).To(typeof(ImplementationClass));
kernel.GetAll(typeof(GenericAbstractClass<int>));