左侧边栏导航组件, 当左侧导航超过一屏高度时, 切换导航具备动画居中成果, 能够滑动右侧区域来切换导航, 滑动到屏幕底部时主动切换到下个导航, 相同滑动到顶部切换上一
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效果图请点击:
次要代码片段:
// 子分类列表
categoryList(id) {
const res = list2
const num = Math.ceil(Math.random() * 5)
console.log(num)
this.classifyList = getRandom(res.data.slice(0, num))
// 注因为这里子分类数据只有一个, 所有采纳打乱程序的形式显示, 理论可依据申请回来的数据来显示
function getRandom(arr) {let [newArr, selItem] = [[], null]
let len = arr.length
while (newArr.length < len) {selItem = arr[Math.floor(Math.random() * len)]
if (!newArr.find((item) => item.id == selItem.id)) {newArr.push(selItem)
}
}
return newArr
}
},
tabNav(index, event) {
const $nav = this.$refs.nav
let {scrollTop, clientHeight, scrollHeight} = $nav
const {clientHeight: itemHeight} = $nav.querySelector('.item'),
len = Math.floor(clientHeight / itemHeight),
middle = Math.ceil(len / 2) - 1,
currentScrollHeight = (index - middle) * itemHeight,
{navIndex} = this,
prevScroll = Math.abs(index - navIndex) * itemHeight
let timer = setInterval(() => {if (navIndex < index) {
scrollTop += prevScroll / 16
$nav.scrollTop = scrollTop
if (scrollTop >= currentScrollHeight) {clearInterval(timer)
timer = null
}
} else {
scrollTop -= prevScroll / 16
$nav.scrollTop = scrollTop
if (scrollTop <= currentScrollHeight) {clearInterval(timer)
timer = null
}
}
}, 20)
this.$refs.list.scrollTo(0, 0)
this.isLowest = false
this.navIndex = index
this.categoryList(this.navList[index].id)
this.swiperPicture(this.navList[index].id)
// this.setClassifyActive(index)
this.getClassifyActive = index
},