private async void AddToCartAsync()
        {
            try
            {
                if (!Tools.IsNetConnective())
                {
                    CrossToastPopUp.Current.ShowToastError("无网络连接,请检查网络。", ToastLength.Long);
                    return;
                }

                RestSharpService _restSharpService = new RestSharpService();

                string memberId       = GlobalVariables.LoggedUser.id.ToString();
                string productId      = Product.productId.ToString();
                string num            = ProductNum.ToString();
                string attributeValue = Product.itemAttributeValues[Index].attributeValue;

                SimpleRD simpleRD = await _restSharpService.AddToCart(memberId, productId, num, attributeValue);

                if (simpleRD.message == "success")
                {
                    CrossToastPopUp.Current.ShowToastSuccess("已添加到购物车!", ToastLength.Short);
                }
                else
                {
                    CrossToastPopUp.Current.ShowToastError("添加到购物车失败!", ToastLength.Long);
                }
            }
            catch (Exception)
            {
                throw;
            }
        }