小程序原生实现左右锚点联动

效果

wxml

<view class='box'><scroll-view scroll-y scroll-with-animation style="width:25%"><view class='nav'><view wx:for="{{navList}}" wx:key='index' class="title {{index == active ?'select':''}}"data-index='{{index}}' bindtap='activeNav'>{{item}}</view></view></scroll-view><scroll-view scroll-y style="width:75%" scroll-with-animation scroll-into-view="{{selectId}}"bindscroll="watchScroll"><view class='content'><view id='{{"item"+index}}' class='subtitle' wx:for="{{navList}}" wx:key='index'>{{item}}</view></view></scroll-view>
</view>

css

.box {display: flex;
}
.nav {height: 100%;width: 100%;background: #F5F5F5;box-sizing: border-box;flex-wrap: wrap;
}.title {box-sizing: border-box;width: 100%;padding: 32rpx;font-size: 28rpx;
}.select {background: #fff;border-left: 5rpx solid #eec718;box-sizing: border-box;
}.content {padding: 0 30rpx;box-sizing: border-box;width: 100%;height: 100vh;
}.subtitle {width: 100%;height: 650rpx;border-bottom: 10rpx #f5f5f5 solid;
}

js

Page({data: {heightArr: [],distance: 0,active: 0,selectId: "item0",navList: ['全部甜品', '今日甜品系列', '毛巾卷系列', '切块系列', '限时限量系列', '提拉米苏系列']},onLoad: function (options) {this.selectHeight();},// 选择左侧标签锚点定位activeNav(e) {var index = e.currentTarget.dataset.indexthis.setData({active: index,selectId: "item" + index})},//计算右侧每个锚点的高度selectHeight() {var list = []var height = 0;const query = wx.createSelectorQuery();query.selectAll('.subtitle').boundingClientRect()query.exec((res) => {res[0].forEach((item) => {height += item.height;list.push(height)})this.data.heightArr = list})},//监听scroll-view的滚动事件watchScroll(e) {let scrollTop = e.detail.scrollTop; //获取距离顶部的距离let active = this.data.active;if (scrollTop >= this.data.distance) {if (active + 1 < this.data.heightArr.length && scrollTop >= this.data.heightArr[active]) {this.setData({active: active + 1})}} else {if (active - 1 >= 0 && scrollTop < this.data.heightArr[active - 1]) {this.setData({active: active - 1})}}this.data.distance = scrollTop;}
})