How to correctly implement an interface on a C# repository

Question

I am currently working on an ASP.NET MVC application in which controllers use repositories to access data via the Entity Framework ORM.

Below is a basic example of interfaces and repositories used by my ASP.NET MVC controllers to access data.

I am experiencing high numbers of my repositories being left in GC Gen2 memory and I wondered if it was as a result of my design pattern?

Any advice on this would be appreciated. I understand that the architecture could be improved and such comments would also be appreciated but my main focus surrounds my high memory usage.

The Controller

[SessionState(SessionStateBehavior.ReadOnly)]
public class GridCustomerServiceController : Controller
{
    private ICustomerServiceRepository _customerServiceRepository { get; set; }

    #region Constructor 

    public GridCustomerServiceController()
    {
        _customerServiceRepository = new CustomerServiceRepository();
    }

    #endregion Constructor

    #region Overrides
    protected override void Dispose(bool disposing)
    {
        this._customerServiceRepository.Dispose();

        base.Dispose(disposing);
    }
    #endregion Overrides

    [GridAction]
    [Authorize(Roles = "user")]
    public ActionResult _CustomerServicesSelect()
    {
            return View(new GridModel  
                {
                    Data =
                        (_customerServiceRepository.GetServicesByCustomerId(1))
                });

    }

The Interface

    using System.Linq;
    public interface ICustomerProductRepository
    {
        void Dispose();
        IQueryable<CustomerProduct> GetProductObjectsByCustomerId(int cid);
        void Add(Customer b);
        void Delete(Customer c);
        void Save();
    }

The Repository

    public class CustomerProductRepository : ICustomerProductRepository
    {
        private myEntities db = new myEntities();

          #region Dispose Methods

        ~CustomerProductRepository()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (db != null)
            {
                db.Dispose();
                db = null;
            }
        }

         #endregion Dispose Methods

        public void Delete(CustomerProduct c)
        {
            db.CustomerProducts.DeleteObject(c);
        }
        public void Save()
        {
            db.SaveChanges();
        }
        public void AddCustomerProduct(CustomerProduct b)
        {
            db.AddToCustomerProducts(b);
            db.SaveChanges();
        }
...

Answer 1

Your interface could inherit from the IDisposable interface to have the Dispose method. For sample:

public class CustomerProductRepository : ICustomerProductRepository, IDisposable 
{
   // the same code here...
}

With this, you also could use the following syntax:

using (ICustomerProductRepository repo = new CustomerProductRepository())
{
   // use repository here...

} // auto dispose occurs here

Answer 2

As Felipe mentioned, The key here is to use IDisposable. GC can invoke the IDisposable.Dispose automtically when it runs, so you need not worry. You can also refer here: 1