public IHttpActionResult Post(EnrollmentCreate enrollments)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }
            var service = CreateEnrollmentService();

            if (!service.CreateEnrollment(enrollments))
            {
                return(InternalServerError());
            }
            return(Ok());
        }
        public bool CreateEnrollment(EnrollmentCreate model)
        {
            var entity =
                new Enrollment()
            {
                UserID     = model.UserID,
                ActivityID = model.ActivityID,
            };

            using (var ctx = new ApplicationDbContext())
            {
                ctx.Enrollments.Add(entity);
                return(ctx.SaveChanges() == 1);
            }
        }