在我們移動項目開發(fā)中加勤，經(jīng)常會處理滾動列表的功能，有的是橫向滾動列表同波，有的是縱向滾動列表鳄梅。我們在實現(xiàn)這類滾動效果的時候，一般會使用better-scroll插件未檩。
better-scroll是基于移動端滾動的解決方案戴尸，它是基于iscroll重寫。better-scroll很強大冤狡，不僅可以做普通的滾動列表孙蒙，還可以做輪播圖、Picker等等悲雳。
今天我就以“餓了么”來講解如何使用better-scroll挎峦。先看“餓了么”動圖：

餓了么

今天我們主要實現(xiàn)以下幾個功能：

1、左右側(cè)頁面滑動合瓢，并且不顯示滾動條

2坦胶、根據(jù)左側(cè)的商品類別對應(yīng)到右側(cè)相應(yīng)的選擇區(qū)間，并且高亮標題

3、根據(jù)右側(cè)用戶滑動的區(qū)間顿苇，能夠?qū)?yīng)到左側(cè)的商品類別峭咒，并且高亮選擇標題

安裝插件

這個很簡單，一句話就搞定纪岁。

npm install--save better-scroll

以下我們就直接上代碼凑队，需要注意的地方我們會說明

樣式代碼

[v-cloak] {
            display: none;
        }

        .goods {
            position: absolute;
            width: 100%;
            top: 174px;
            bottom: 46px;
            display: flex;
            overflow: hidden;
        }

        .goods .menu-wrapper {
            flex: 0 0 80px;
            width: 80px;
            background: #f3f5f7;
        }

        .goods .menu-wrapper .current {
            position: relative;
            z-index: 10;
            margin-top: -1px;
            background: #FFFFFF;
            font-weight: 700;
            font-size: 14px;
        }

        .goods .menu-wrapper .menu-item {
            display: table;
            height: 54px;
            width: 80px;
            line-height: 14px;
            padding: 0 12px;
            border-bottom: 1px solid rgba(7, 17, 27, .1);
            box-sizing: border-box;
        }

        .goods .menu-wrapper .menu-item .icon {
            display: inline-block;
            width: 12px;
            height: 12px;
            margin-right: 2px;
            -webkit-background-size: 12px 12px;
            background-size: 12px 12px;
            background-repeat: no-repeat;
            vertical-align: top;
        }

        .goods .menu-wrapper .menu-item .text {
            display: table-cell;
            width: 56px;
            vertical-align: middle;
            font-size: 12px;
            text-align: center;
        }

        .goods .menu-wrapper .menu-item .decrease {
            background-image: url(img/decrease_2@2x.png);
        }

        .goods .menu-wrapper .menu-item .discount {
            background-image: url(img/decrease_2@2x.png);
        }

        .goods .menu-wrapper .menu-item .guarantee {
            background-image: url(img/decrease_2@2x.png);
        }

        .goods .menu-wrapper .menu-item .invoice {
            background-image: url(img/decrease_2@2x.png);
        }

        .goods .menu-wrapper .menu-item .special {
            background-image: url(img/decrease_2@2x.png);
        }

        .goods .foods-wrapper {
            flex: 1;
        }

        .goods .foods-wrapper .title {
            padding-left: 14px;
            height: 26px;
            line-height: 26px;
            border-left: 2px solid #d9dde1;
            font-size: 12px;
            color: rgb(147, 153, 159);
            background: #F3F5F7;
        }

        .goods .foods-wrapper .current {
            color: #42B983;
            font-size: 14px;
            transition: all .5s;
            line-height: 27px;
        }

        .goods .foods-wrapper .food-item {
            display: flex;
            margin: 18px 0 18px 0;
            border-bottom: 1px solid rgba(7, 17, 27, .1);
            padding-bottom: 18px;
        }

        .goods .foods-wrapper .food-item:last-child {
            border-bottom: 0px solid rgba(7, 17, 27, .1);
            margin-bottom: 0;
        }

        .goods .foods-wrapper .food-item .icon {
            flex: 0 0 57px;
            margin-right: 10px;
            margin-left: 10px;
        }

        .goods .foods-wrapper .food-item .content {
            position: relative;
            flex: 1;
        }

        .goods .foods-wrapper .food-item .content .name {
            margin: 2px 0 8px 0;
            height: 14px;
            line-height: 14px;
            font-size: 14px;
            color: rgb(7, 17, 27);
        }

        .goods .foods-wrapper .food-item .content .desc {
            margin-bottom: 8px;
            line-height: 10px;
            font-size: 10px;
            color: rgb(147, 153, 159);
        }

        .goods .foods-wrapper .food-item .content .extra {
            font-size: 10px;
            color: rgb(147, 153, 159);
            line-height: 10px;
        }

        .goods .foods-wrapper .food-item .content .extra .count {
            margin-right: 12px;
        }

        .goods .foods-wrapper .food-item .content .price {
            font-weight: 700;
            line-height: 24px;
        }

        .goods .foods-wrapper .food-item .content .price .now {
            margin-right: 8px;
            font-size: 14px;
            color: rgb(240, 20, 20);
        }

        .goods .foods-wrapper .food-item .content .price .old {
            text-decoration: line-through;
            font-size: 10px;
            color: rgb(147, 153, 159);
        }

        .goods .foods-wrapper .food-item .content .cartcontrol-wrapper {
            position: absolute;
            right: 6px;
            bottom: 12px;
        }

頁面布局

<template>
<div class="goods" v-cloak>
            <div class="menu-wrapper" ref="menuwrapper">
                <ul>
                    <!--當currentIndex與index相等的時候，設(shè)置高亮-->
                    <li v-for="(item,index) in goods" class="menu-item" :class="{'current':currentIndex === index}" @click="selectMenu(index,$event)" v-cloak>
                        <span class="text">
                                <span v-show="item.type>0" class="icon" :class="classMap[item.type]" v-cloak></span> {{item.name}}
                        </span>
                    </li>
                </ul>
            </div>
            <div class="foods-wrapper" ref="foodwrapper">
                <ul>
                    <!--food-list-hook用于dom操作幔翰，獲取整體容器的高度-->
                    <li v-for="(item,index) in goods" class="food-list food-list-hook" v-cloak>
                        <h2 class="title" :class="{'current':currentIndex === index}">{{item.name}}</h2>
                        <ul>
                            <li @click="selectfood(food,$event)" v-for="food in item.foods" class="food-item">
                                <div class="icon">
                                    ![](food.icon)
                                </div>
                                <div class="content">
                                    <h2 class="name">{{food.name}}</h2>
                                    <p class="desc">{{food.description}}</p>
                                    <div class="extra">
                                        <span class="count">月售{{food.sellCount}}份</span>
                                        <span>好評率{{food.rating}}%</span>
                                    </div>
                                    <div class="price">
                                        <span class="now">￥{{food.price}}</span>
                                        <span v-show="food.oldPrice" class="old">￥{{food.oldPrice}}</span>
                                    </div>
                                </div>
                            </li>
                        </ul>
                    </li>
                </ul>
            </div>
        </div>  
</template>

JS代碼

<script>
export default {
 data() {
      return {
       msg: 'goods',
                goods: [],
                listHeight: [],
                scrollY: 0,
      }
    },
created() {
                this.classMap = ['decrease', 'discount', 'guarantee', 'invoice', 'special'];
                this.$http.get('./data.json').then((res) => {
                    if(res.status === ERR_OK) {
                        res = res.body.goods;
                        this.goods = res;
                        //dom結(jié)構(gòu)加載結(jié)束
                        this.$nextTick(() => {
                            this._initScroll();
                            //計算高度
                            this._calculateHeight();
                        })
                    }
                });
            },
computed: {
                currentIndex() {
                    for(let i = 0; i < this.listHeight.length; i++) {
                        //判斷當currentIndex在height1和height2之間的時候顯示
                        let height1 = this.listHeight[i];
                        let height2 = this.listHeight[i + 1];
                        //          console.log('height1:'+height1+','+'height2:'+height2)
                        //最后一個區(qū)間沒有height2
                        if(!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
                            return i;
                        }
                    }
                    return 0;
                }
            },
methods: {
                selectMenu(index, event) {
                    //      自己默認派發(fā)事件時候(BScroll),_constructed被置為true,但是瀏覽器原生并沒有這個屬性
                    if(!event._constructed) {
                        return;
                    }
                    //運用BScroll接口顽决，滾動到相應(yīng)位置
                    let foodList = this.$refs.foodwrapper.getElementsByClassName('food-list-hook');
                    //獲取對應(yīng)元素的列表
                    let el = foodList[index];
                    this.foodScroll.scrollToElement(el, 300);
                },
                 /*
                  _initScroll的函數(shù)，主要用來對左右兩側(cè)dom結(jié)構(gòu)進行初始化 
                 用better-scroll的方法初始化需要滾動的dom結(jié)構(gòu)导匣，
                vue為我們提供了一個方法可以便利的獲取到 dom結(jié)構(gòu)才菠，
                我們在需要獲取dom結(jié)構(gòu)的父容器內(nèi)添加ref="foodwrapper" ，
               然后在函數(shù)內(nèi)用this.$refs.menuwrapper獲取到dom
                */
                _initScroll() {
                    this.meunScroll = new BScroll(this.$refs.menuwrapper, {
                        click: true
                    });
                    this.foodScroll = new BScroll(this.$refs.foodwrapper, {
                        click: true,
                        //探針作用贡定，實時監(jiān)測滾動位置
                        probeType: 3
                    });
                    //設(shè)置監(jiān)聽滾動位置
                    this.foodScroll.on('scroll', (pos) => {
                        //scrollY接收變量
                        this.scrollY = Math.abs(Math.round(pos.y));
                    })
                },
                _calculateHeight() {
                    let foodList = this.$refs.foodwrapper.getElementsByClassName('food-list-hook');
                    let height = 0;
                    //把第一個高度送入數(shù)組
                    this.listHeight.push(height);
                    //通過循環(huán)foodList下的dom結(jié)構(gòu)赋访，將每一個li的高度依次送入數(shù)組
                    for(let i = 0; i < foodList.length; i++) {
                        let item = foodList[i]
                        height += item.clientHeight
                        this.listHeight.push(height);
                    }
                },
            }
}
</script>

最后完整的效果圖如下：

最終效果圖