public EchangeLivreController()
        {
            SQLRepositoryLivreEchange contextEchange = new SQLRepositoryLivreEchange(new MyContext());

            SQLRepositoryUtilisateur contextUser = new SQLRepositoryUtilisateur(new MyContext());

            serviceUser = new UtilisateurService(contextUser);

            serviceEchange = new EchangeLivreService(contextEchange);
        }
        public CategoriesController()
        {
            contextUser           = new SQLRepositoryUtilisateur(new MyContext());
            this.contextCategorie = new SQLRepository <Categorie>(new MyContext());
            this.contextLivre     = new SQLRepositoryLivre(new MyContext());
            this.contextWishList  = new SQLRepositoryWishList(new MyContext());
            serviceBook           = new BookService(contextLivre);

            SQLRepositoryLivreEchange ech = new SQLRepositoryLivreEchange(new MyContext());

            echangeService = new EchangeLivreService(ech);
        }