Ninject将泛型接口绑定到具有多个参数的泛型具体类

Question

This is strange, I'm using Ninject for dependency injection and I had no problem in binding until I bound a generic interface to a generic concrete class which is shown below:

// * Two below bindings are like many other bindings that are OK
Bind<ISupplierAssessmentMarkBiz>()
    .To<SupplierAssessmentMarkBiz>().InRequestScope();
Bind<ISupplierAssessmentDetailBiz>()
    .To<SupplierAssessmentDetailBiz>().InRequestScope();
// * This below binding is problematic
Bind(typeof(IHierarchyEntityBiz<KnowledgeDTO>))
    .To(typeof(HierarchyEntityBiz<Knowledge, KnowledgeDTO>)).InRequestScope();

Then in my controller's constructor I have this:

public KnowledgeController(AuthenticationService authSvc, IKnowledgeBiz knowledgeBiz,
    IHierarchyEntityBiz<KnowledgeDTO> knowledgeHierarchyBiz)
        : base(authSvc)
    {
        _knowledgeBiz = knowledgeBiz;
        _knowldegHierarchyBiz = knowledgeHierarchyBiz;
    }

So when I try to call a web api service, I get this error:

'...KnowledgeController' does not have a default constructor.

And in output window:

'A first chance exception of type 'Ninject.ActivationException' occurred in Ninject.dll'

Any help would be appreciated.

Answer 1

Replacing

Bind(typeof(IHierarchyEntityBiz<KnowledgeDTO>))
.To(typeof(HierarchyEntityBiz<Knowledge, KnowledgeDTO>)).InRequestScope();

with

Bind<IHierarchyEntityBiz<KnowledgeDTO>>()
.To<HierarchyEntityBiz<Knowledge, KnowledgeDTO>>().InRequestScope();

should not change anything but it might be worth a try ;-) If it doesn't help, it's at least a little bit shorter.

So for your issue. Please give us the entire message of the exception. It should contain the activation stack, so we can see why ninject tried to instanciate a KnowledgeController .

Most likely you are missing bindings for AuthenticationService or IKnowledgeBiz .