vue左右侧联动滚动的实现代码

本文介绍了vue左右侧联动滚动的实现代码,分享给大家,具体如下:

实现功能:

  1. 点击左侧,右侧滚动到相应位置,
  2. 滚动右侧, 左侧滚动到相应位置

布局结构:

开源滚动库:

better-scroll.js

技术要点:

1.<scroll>是对紧邻的元素生效

如:

<scroll class='foods-wrapper'>

<ul class=content>

<li></li>

</ul>

</scroll>

初始化在<ul>元素上

2.foods-wrapper的高度小于content高度时才会发生滚动

3.点击左侧菜单列表时,只需要计算右侧对应的偏移距离 或是 计算对应的移动到的元素即可

方法一: 计算移动距离, 用scrollTo()方法

for (let i = 0; i < index; i++) {

height += this.$refs.item[i].offsetHeight

}

this.$refs.foodsWrapper.scrollTo(0, -height)

方法二: 计算移动到的元素,用scrollToElement()方法

let foodsEle = this.$refs.foodsUl.getElementsByClassName('item')[index]

this.$refs.foodsWrapper.scrollToElement(foodsEle, 400)

4.滚动右侧列表时,会稍复杂一些.

4.1. 因为需要知道滚动的元素在哪个item列表区间, 因此需要计算右侧五组item距离顶部的距离

_heightArr () {

let h = 0

let list = this.$refs.item

list.forEach((item, i) => {

h += list[i].clientHeight

this.itemHeight.push(h)

})

console.log(this.itemHeight) //[0, 481, 850, 2227, 2820, 3189]

}

4.2 时时监听滚动距离

需要在<scroll>中加以下参数

<scroll class='foods-wrapper' :listenScroll=listenScroll :probeType = 'probeType' @scroll=scroll>

其中 listenScroll probeType参数 在created中定义:

created () {

this.listenScroll = true

this.probeType = 3

}

而@scroll=scroll是在scroll.vue中代理过来的方法:

//scroll.vue

if (this.listenScroll) {

let me = this

this.scroll.on('scroll', (position) => {

me.$emit('scroll', position) //参数position: position:{x:-10, y:24}

})

}

posiiton.y就是需要实时监听的参数,即:

scroll (position) {

this.scrolly = position.y

}

其中 scrolly 需要在data中提前定义:

data () {

return {

scrolly: -1

}

}

然后在watch中监听scrolly变化即可:

watch: {

scrolly (newy) {

if (newy >= 0) this.currentIndex = 0

let itemHeight = this.itemHeight

for (let i = 0; i < itemHeight.length - 1; i++) {

let h1 = itemHeight[i]

let h2 = itemHeight[i + 1]

if (-newy >= h1 && -newy < h2) {

this.currentIndex = i

return

}

}

}

}

代码部分:

//左侧结构

<scroll class='menu-wrapper'>

<ul>

<li

v-for='(item,index) in foodsList'

:key=index

class=item

:class="{active:currentIndex === index}"

@click=selectMenu(index)

>

<span>{{item.name}}</span>

</li>

</ul>

</scroll>

//右侧结构

<scroll class='foods-wrapper' ref=foodsWrapper :listenScroll=listenScroll :probeType = 'probeType' @scroll=scroll>

<ul ref=foodsUl>

<li v-for='(item,index) in foodsList' :key=index class=item ref=item :data-index=index>

<div class=title><span class='title-name'>{{item.name}}</span><span>{{item.description}}</span></div>

<ul>

<li v-for='(food,i) in item.foods' :key=i class=food>

//.........

//略去右侧详情代码

</li>

</ul>

</li>

</ul>

</scroll>

//js部分

<script>

import Scroll from "base/scroll"

const H = 112

export default {

data () {

return {

currentIndex: 0,

offset: 0,

scrolly: -1

}

},

created () {

this.listenScroll = true

this.probeType = 3

this.itemHeight = [0]

},

mounted () {

this.$nextTick(() => {

this._heightArr()

}, 20);

},

methods: {

selectMenu (index) {

let height = 0

this.currentIndex = index

for (let i = 0; i < index; i++) {

height += this.$refs.item[i].offsetHeight

}

let foodsEle = this.$refs.foodsUl.getElementsByClassName('item')[index]

this.$refs.foodsWrapper.scrollToElement(foodsEle, 400)

// this.$refs.foodsWrapper.scrollTo(0, -height)

this.offset = height

},

scroll (position) {

this.scrolly = position.y

},

_heightArr () {

let h = 0

let list = this.$refs.item

list.forEach((item, i) => {

h += list[i].clientHeight

this.itemHeight.push(h)

})

}

},

watch: {

scrolly (newy) {

if (newy >= 0) this.currentIndex = 0

let itemHeight = this.itemHeight

for (let i = 0; i < itemHeight.length - 1; i++) {

let h1 = itemHeight[i]

let h2 = itemHeight[i + 1]

if (-newy >= h1 && -newy < h2) {

this.currentIndex = i

return

}

}

}

},

components: {

Scroll

}

}

</script>

//scroll.vue

<template>

<div ref=wrapper>

<slot></slot>

</div>

</template>

<script>

import BScroll from 'better-scroll'

export default {

props: {

probeType: {

type: Number,

default: 1//* 1 滚动的时候会派发scroll事件,会截流。 * 2 滚动的时候实时派发scroll事件,不会截流。 * 3 除了实时派发scroll事件,在swipe的情况下仍然能实时派发scroll事件

},

click: {

type: Boolean,

default: true

},

scrollX: {

type: Boolean,

default: false

},

data: {

type: Array,

default: null

},

listenScroll: {

type: Boolean,

default: false

},

},

mounted () {

this.$nextTick(() => {

this.initScroll()

}, 20)

},

methods: {

initScroll () {

if (!this.$refs.wrapper) return

this.scroll = new BScroll(this.$refs.wrapper, {

probeType: this.probeType,

click: this.click,

scrollX: this.scrollX

})

if (this.listenScroll) {

let me = this

this.scroll.on('scroll', (position) => {

me.$emit('scroll', position)

})

}

},

enable () {

this.scroll && this.scroll.enable()

},

disable () {

this.scroll && this.scroll.disable()

},

refresh () {

this.scroll && this.scroll.refresh()

},

scrollTo () {

this.scroll && this.scroll.scrollTo.apply(this.scroll, arguments)

},

scrollToElement () {

this.scroll && this.scroll.scrollToElement.apply(this.scroll, arguments)

}

},

watch: {

data () {

setTimeout(() => {

this.scroll.refresh()

}, 20)

}

}

}

</script>

以上是 vue左右侧联动滚动的实现代码 的全部内容, 来源链接: utcz.com/z/336687.html

回到顶部