vue左右側(cè)聯(lián)動滾動的實現(xiàn)代碼

更新時間：2018年06月06日 09:09:45 作者：豌豆突突突

這篇文章主要介紹了vue左右側(cè)聯(lián)動滾動的實現(xiàn)代碼，小編覺得挺不錯的，現(xiàn)在分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

本文介紹了vue左右側(cè)聯(lián)動滾動的實現(xiàn)代碼，分享給大家，具體如下：

實現(xiàn)功能:

點擊左側(cè),右側(cè)滾動到相應(yīng)位置,
滾動右側(cè), 左側(cè)滾動到相應(yīng)位置

布局結(jié)構(gòu):

開源滾動庫:

better-scroll.js

技術(shù)要點:

1.<scroll>是對緊鄰的元素生效

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高度時才會發(fā)生滾動

3.點擊左側(cè)菜單列表時,只需要計算右側(cè)對應(yīng)的偏移距離或是計算對應(yīng)的移動到的元素即可

方法一: 計算移動距離, 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: 計算移動到的元素,用scrollToElement()方法

 let foodsEle = this.$refs.foodsUl.getElementsByClassName('item')[index]
 this.$refs.foodsWrapper.scrollToElement(foodsEle, 400)

4.滾動右側(cè)列表時,會稍復雜一些.

4.1. 因為需要知道滾動的元素在哪個item列表區(qū)間, 因此需要計算右側(cè)五組item距離頂部的距離

_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 時時監(jiān)聽滾動距離

需要在<scroll>中加以下參數(shù)

復制代碼代碼如下:

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

其中 listenScroll probeType參數(shù) 在created中定義:

 created () {
  this.listenScroll = true
  this.probeType = 3
 }

而@scroll=scroll是在scroll.vue中代理過來的方法:

 //scroll.vue
 if (this.listenScroll) {
  let me = this
  this.scroll.on('scroll', (position) => {
   me.$emit('scroll', position) //參數(shù)position: position:{x:-10, y:24}
  })
 }

posiiton.y就是需要實時監(jiān)聽的參數(shù),即:

scroll (position) {
 this.scrolly = position.y
}

其中 scrolly 需要在data中提前定義:

 data () {
  return {
   scrolly: -1
  }
 }

然后在watch中監(jiān)聽scrolly變化即可:

 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
    }
   }
  }
 }

代碼部分:

//左側(cè)結(jié)構(gòu)
 <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>


//右側(cè)結(jié)構(gòu)
 <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>
     //.........
     //略去右側(cè)詳情代碼
     </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 滾動的時候會派發(fā)scroll事件，會截流。 * 2 滾動的時候?qū)崟r派發(fā)scroll事件，不會截流。 * 3 除了實時派發(fā)scroll事件，在swipe的情況下仍然能實時派發(fā)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>

以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

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