public AnswerByPhoneData getAnswerByPhoneAndActivityID(long ActivityID, string StudentPhone, long RoomId)
        {
            List <AnswerByPhoneData> allAnswersByPhone = AnswersByPhone.ToList();

            foreach (AnswerByPhoneData sData in allAnswersByPhone)
            {
                if (sData.ActivityId == ActivityID && sData.Phone == StudentPhone && sData.RoomID == RoomId)
                {
                    return(sData);
                }
            }

            return(null);
        }
        public List <ActivityData> getActivitiesByStudentPhone(string studentPhone, long RoomID)
        {
            List <ActivityData>      lstData           = new List <ActivityData>();
            List <AnswerByPhoneData> allAnswersByPhone = AnswersByPhone.ToList();

            // Add all the questions activities of a student
            foreach (AnswerByPhoneData sData in allAnswersByPhone)
            {
                if (sData.Phone == studentPhone && sData.RoomID == RoomID)
                {
                    ActivityData ad = getActivity(sData.ActivityId);
                    if (ad.expID == -1)
                    {
                        lstData.Add(ad);
                    }
                }
            }

            // TODO Add all the experiments activities of a student

            return(lstData);
        }