How can you inject an asp.net (mvc2) custom membership provider using Ninject?

Question

OK, so I've been working on this for hours. I've found a couple of posts here, but nothing that actually resolves the problem. So, let me try it again...

I have an MVC2 app using Ninject and a custom membership provider.

If I try and inject the provider using the ctor, I get an error: 'No parameterless constructor defined for this object.'

public class MyMembershipProvider : MembershipProvider
{
    IMyRepository _repository;

    public MyMembershipProvider(IMyRepository repository)
    {
        _repository = repository;
    }

I've also been playing around with factories and Initialize(), but everything is coming up blanks.

Any thoughts/examples?

Answer 1

This is how I was able to do this:

1) I created a static helper class for Ninject

public static class NinjectHelper
{
    public static readonly IKernel Kernel = new StandardKernel(new FooServices());

    private class FooServices : NinjectModule
    {
        public override void Load()
        {
            Bind<IFooRepository>()
                .To<EntityFooRepository>()
                .WithConstructorArgument("connectionString",
                    ConfigurationManager.ConnectionStrings["FooDb"].ConnectionString);
        }
    }
}

2) Here is my Membership override:

    public class FooMembershipProvider : MembershipProvider
    {
        private IFooRepository _FooRepository;

        public FooMembershipProvider()
        {
            NinjectHelper.Kernel.Inject(this);
        }

        [Inject]
        public IFooRepository Repository 
        { 
            set
            {
                _FooRepository = value;
            }
        }
        ...

With this approach it doesn't really matter when the Membership provider is instantiated.

Answer 2

The Membership provider model can only instantiate a configured provider when it has a default constructor. You might try this using the Service Locator pattern, instead of using Dependency Injection. Example:

public class MyMembershipProvider : MembershipProvider
{
    IMyRepository _repository;

    public MyMembershipProvider()
    {
        // This example uses the Common Service Locator as IoC facade, but
        // you can change this to call NInject directly if you wish.
        _repository = ServiceLocator.Current.GetInstance<IMyRepository>;
    }

Answer 3

I had the same problem at the exact same spot in the book. It wasn't until later on in the book that I noticed there were two separate web.config files. I initially placed my connectionString key in the wrong web.config file. It wasn't until I placed the connectionString in the correct web.config file that the 'no parameterless constructor' error went away.