Using Generic Repository with TEntity in Unity

Question

I am learning how to use the Unity Framework for Dependency Injection in asp.net MVC 5 projects.

In general, I would set up a mapping for my repositories like this:

public static void RegisterComponents()
{
    var container = new UnityContainer();

    // e.g. container.RegisterType<ITestService, TestService>();
    container.RegisterType<IModelRepository, ModelRepository>();

    DependencyResolver.SetResolver(new UnityDependencyResolver(container));
}

Is it possible to do this with a generic Repository which looks like this:

 public class GenericRepository<TEntity> 
       : IGenericRepository<TEntity> where TEntity : class
 { /* ... */ }

Out of instinct I would set up and register this like this:

container.RegisterType<IGenericRepository<TEntity>, GenericRepository<TEntity>>();

which does not work.

Do I need to register a Generic Repository for every model type like this?

container.RegisterType<IGenericRepository<Model1>, GenericRepository<Model1>>();
container.RegisterType<IGenericRepository<Model2>, GenericRepository<Model2>>();
container.RegisterType<IGenericRepository<Model3>, GenericRepository<Model3>>();
...
container.RegisterType<IGenericRepository<Model_N>, GenericRepository<Model_N>>();

Or is there a way to inject this repository once for all model classes and controllers?

Answer 1

You can register the generic types for any TEntity this way:

container.RegisterType(typeof(IGenericRepository<>), typeof(GenericRepository<>));

See the msdn on Unity 2.1 or Unity 3 (Registering Open Generics section)