IRepositoryBase

IRepositoryBase.cs

public interface IRepositoryBase<TEntity> where TEntity : class 
    {
        TEntity Add(TEntity item);
        TEntity GetById(int id);
        IEnumerable<TEntity> Get();
        bool Update(TEntity item);
        int Count();
        void Dispose();
    }

RepositoryBase.cs

public class RepositoryBase<TEntity> : IDisposable, IRepositoryBase<TEntity> where TEntity : class
    {
        protected MyEntities Db = new MyEntities();

        public void Dispose()
        {
            throw new NotImplementedException();
        }

        public TEntity Add(TEntity item)
        {
            try
            {
                TEntity adicionado = Db.Set<TEntity>().Add(item);
                Db.SaveChanges();
                return adicionado;
            }
            catch (DbUpdateConcurrencyException ex)
            {
                Console.WriteLine(ex.InnerException);
                return null;
            }
        }

        public TEntity GetById(int id)
        {
            return Db.Set<TEntity>().Find(id);
        }

        public IEnumerable<TEntity> Get()
        {
            return Db.Set<TEntity>().ToList();
        }

        public bool Update(TEntity item)
        {
            try
            {
                Db.Entry(item).State = EntityState.Modified;
                Db.SaveChanges();
                return true;
            }
            catch (DbUpdateConcurrencyException ex)
            {
                Console.WriteLine(ex.InnerException);
                return false;
            }
        }

        public int Count()
        {
            return Db.Set<TEntity>().Count();
        }
    }