/// <summary>
        /// 销售会员产品
        /// </summary>
        /// <param name="tutorName">教师姓名</param>
        /// <param name="productId">产品Id</param>
        /// <param name="customerName">顾客姓名</param>
        /// <param name="phoneNumber">顾客手机号码</param>
        public void Sell(string tutorName, Guid productId, string customerName, string phoneNumber)
        {
            var tutor   = _tutorMgr.GetByName(tutorName);
            var product = _productMgr.GetById(productId);

            //if (product is OneTimeExperience)
            //    throw new

            using (TransactionScope scope = new TransactionScope())
            {
                bool       isNewMember = false;
                SellRecord sellRecord;
                Member     member = null;
                if (product is MemberProduct)
                {
                    member = _memberMgr.GetByPhoneNumber(phoneNumber);
                    if (member == null)
                    {
                        member = new Member()
                        {
                            Name        = customerName,
                            PhoneNumber = phoneNumber
                        };
                        isNewMember = true;
                    }
                    sellRecord = ((MemberProduct)product).Sell(tutor, member);
                    _sellRecordMgr.Save(sellRecord);
                    _memberMgr.Save(member);
                }
                scope.Complete();
            }
        }
        private void btnConsume_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(txtPhoneNumber.Text))
            {
                XtraMessageBox.Show("请先输入顾客的手机号码!");
                txtPhoneNumber.Focus();
                return;
            }

            string phoneNumber = txtPhoneNumber.Text.Trim();
            Member member      = _memberMgr.GetByPhoneNumber(phoneNumber);

            if (member == null)
            {
                XtraMessageBox.Show(string.Format("系统中不存在手机号码为“{0}”的顾客!", phoneNumber),
                                    "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }
            else
            {
                bindingSourceMemberCard.DataSource = member.MemberCards.OfType <TimesCardMemberCard>();
            }
        }