addBuyNum(e, that) {

    let nowNum = e.currentTarget.dataset.addnum;//当前选中商品的数量

    let goodsId = e.currentTarget.dataset.goodsid;//商品id

    let currentGoodsList = that.data.checkGoodsType;//商品列表

    let iconType = e.currentTarget.dataset.type;//是增加商品还是减少商品

    let stock = e.currentTarget.dataset.stock;//获取到商品列表时得知的商品库存

    let index = e.currentTarget.dataset.index;

    let item = e.currentTarget.dataset.item;

    let shoppingCart = that.data.shoppingCart;//购物车中的商品

    let goodsInfo = that.data.goodsInfo;//总商品

    let ShoppingCartTotalPrice = 0;//购物车总价

    if (iconType == 'add') {

        if (nowNum >= stock) {//不请求数据先判断和之前的库存的差值

            that.hud.showWarn("该商品库存不足", 2000);

            item.buyNum = nowNum;

            currentGoodsList.goodslist[index] = item;

            that.setData({

                checkGoodsType: currentGoodsList

            });

        }else{

            item.buyNum = nowNum+1;//库存够

            currentGoodsList.goodslist[index] = item;

            //保存选择状态

            for (var goodsInfoItem in goodsInfo) {

                if (goodsInfo[goodsInfoItem].id == currentGoodsList.id) {

                    goodsInfo[goodsInfoItem] = currentGoodsList;

            }

        }

        that.setData({

            checkGoodsType: currentGoodsList,

            goodsInfo: goodsInfo

        });

//加入购物车

    if (shoppingCart.length == 0) {

        item.totalPrice = (item.buyNum * item.saleprice);

        item.totalPrice = Common.numberToFixed(item.totalPrice);

        that.setData({    

            shoppingCart: new Array(item),

            ShoppingCartTotalPrice: item.totalPrice

        });

    } else {

            if (shoppingCart.map(goodsInCart => goodsInCart.id).indexOf(goodsId) == -1) {

                item.totalPrice = (item.buyNum * item.saleprice);

                item.totalPrice = Common.numberToFixed(item.totalPrice);

                shoppingCart = shoppingCart.concat(item);

            } else {

                shoppingCart.map((goodsInCart) => {

                    if (goodsId == goodsInCart.id) {

                            goodsInCart.buyNum = goodsInCart.buyNum + 1;

                            goodsInCart.totalPrice = (goodsInCart.buyNum * goodsInCart.saleprice);

                            goodsInCart.totalPrice = Common.numberToFixed(goodsInCart.totalPrice);

                    }

            });

            shoppingCart = shoppingCart.concat([]);

        }

        ShoppingCartTotalPrice = +that.data.ShoppingCartTotalPrice + Number(item.saleprice);

        ShoppingCartTotalPrice = Common.numberToFixed(ShoppingCartTotalPrice);

        that.setData({

            shoppingCart: shoppingCart,

            ShoppingCartTotalPrice: ShoppingCartTotalPrice

        })

    }

        }

} else {

//减去商品数量

    item.buyNum = nowNum - 1;

    if (item.buyNum <= 0) { item.buyNum = 0 }

        currentGoodsList.goodslist[index] = item;

        for (var goodsInfoItem in goodsInfo) {

            if (goodsInfo[goodsInfoItem].id == currentGoodsList.id) {

                goodsInfo[goodsInfoItem] = currentGoodsList;

            }

         }

       shoppingCart.map((goodsInCart) => {

        if (goodsId == goodsInCart.id) {

            goodsInCart.buyNum = goodsInCart.buyNum - 1;

            if (goodsInCart.buyNum == 0) {

            var index = shoppingCart.indexOf(goodsInCart);

                    shoppingCart.splice(index, 1);

            }

            goodsInCart.totalPrice = (goodsInCart.buyNum * goodsInCart.saleprice);

            goodsInCart.totalPrice = Common.numberToFixed(goodsInCart.totalPrice);

            return;

        }

        });

        shoppingCart = shoppingCart.concat([]);

        ShoppingCartTotalPrice = +that.data.ShoppingCartTotalPrice - Number(item.saleprice);

        ShoppingCartTotalPrice = Common.numberToFixed(ShoppingCartTotalPrice);

        that.setData({

            checkGoodsType: currentGoodsList,

            goodsInfo: goodsInfo,

            shoppingCart: shoppingCart,

            ShoppingCartTotalPrice: ShoppingCartTotalPrice

         })

}

},