Cannot convert from IGenericReporsitoty<Entity> to IGenericReporsitoty<EntityBase>

Question

I am having an error in my Controller. The repository can't be injected in the base constructor

public class MyController : ControllerCRUDBase<Entity, TournamentDto>
{
    public MyController (IGenericRepository<Entity> repository, IMapper mapper) 
        : base(repository, mapper)
    {
    }
}

Where my ControllerCRUDBase is:

public abstract class ControllerCRUDBase<E, D> : ControllerBase
        where E : EntityBase
        where D : DtoBase
    {
        protected readonly IGenericRepository<EntityBase> _repository;
        protected readonly IMapper _mapper;

        public ControllerCRUDBase(IGenericRepository<EntityBase> repository,
                                  IMapper mapper)
        {
            _repository = repository;
            _mapper = mapper;
        }

My IGenericRepository is:

public interface IGenericRepository<TEntity> where TEntity : EntityBase
    {
    }

And the Entity class is:

public class Entity: EntityBase
{
}

The error is this:

cannot convert from 'IGenericRepository<Entity>' to 'IGenericRepository<EntityBase>'

And I can't understand why.

Answer 1

You're defining a constraint on the generic parameter E for ControllerCRUDBase, but then directly referencing EntityBase in the subsequent constructor instead. Try the following:

public abstract class ControllerCRUDBase<E, D> : ControllerBase
        where E : EntityBase
        where D : DtoBase
    {
        protected readonly IGenericRepository<E> _repository;
        protected readonly IMapper _mapper;

        public ControllerCRUDBase(IGenericRepository<E> repository,
                                  IMapper mapper)
        {
            _repository = repository;
            _mapper = mapper;
        }
    }