基于el-scrollbar封装滚动条

Element UI中内置的滚动条插件el-scrollbar，但没有公示在文档中，这里基于它封装一个组件，提供回到顶部、滚动放向、最大高度功能。完整代码在最后。

基础结构

接收height属性，可以动态设置高度，默认是100%

<template>
  <el-scrollbar
    :class="['scroll-bar']"
    ref="scroll"
    :style="style">
    <slot />
  el-scrollbar>
template>

<script>
export default {
  props: {
    height: {
      type: String,
      default () {
        return '100%'
      }
    }
  },
  data () {
    return {
    }
  },
  computed: {
    style () {
      return {
        height: this.height
      }
    }
  },
  methods: {
  }
}
script>

<style lang="scss">
.scroll-bar {
  .el-scrollbar__wrap {
    overflow-x: hidden; // 去除横向滚动条
  }
}
style>
<style lang="scss" scoped>
style>

引入页面即可使用，注意百分比需要父级有高度，这种常用组件可以全局注册，使用更加便捷。

<template>
  <div style="width: 400px; height: 400px; margin: 0 auto;">
    <scroll-bar>
      <ul>
        <li
          v-for="item in 100"
          :key="item">{{ item }}li>
      ul>
    scroll-bar>
  div>
template>

<script>
import ScrollBar from '@/components/ScrollBar'

export default {
  components: {
    ScrollBar
  }
}
script>

回到顶部

接收toTop属性，需要显示回到顶部按钮设置，默认是false

<template>
  <el-scrollbar
    :class="['scroll-bar']"
    ref="scroll"
    :style="style">
    <slot />
    <div
      v-show="showToTop"
      class="to-top"
      :style="[
        {'background-color': toTopTheme.bgc},
        {'color': toTopTheme.color},
        {'right': toTopPos.right},
        {'bottom': toTopPos.bottom}
      ]"
      @click="handleToTop">
      <i class="el-icon-top">i>
    div>
  el-scrollbar>
template>

<script>
export default {
  props: {
    height: {
      type: String,
      default () {
        return '100%'
      }
    },
    toTop: {
      type: Boolean,
      default () {
        return false
      }
    },
    toTopTheme: {
      type: Object,
      default () {
        return {
          bgc: '',
          color: ''
        }
      }
    },
    toTopPos: {
      type: Object,
      default () {
        return {
          right: '',
          bottom: ''
        }
      }
    }
  },
  data () {
    return {
      showToTop: false
    }
  },
  computed: {
    style () {
      return {
        height: this.height
      }
    }
  },
  mounted () {
    this.toTop && this.$refs.scroll.wrap.addEventListener('scroll', this.scrollFunc)
  },
  methods: {
    scrollFunc (e) {
      const scrollTop = e.target.scrollTop
      if (scrollTop > 80) {
        this.showToTop = true
      } else {
        this.showToTop = false
      }
    },
    handleToTop () {
      // el-scrollbar滚动层为wrap
      this.$refs.scroll.wrap.scrollTo({
        top: 0,
        behavior: 'smooth'
      })
    }
  }
}
script>

<style lang="scss">
.scroll-bar {
  .el-scrollbar__wrap {
    overflow-x: hidden; // 去除横向滚动条
  }
}
style>
<style lang="scss" scoped>
.to-top {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  text-align: center;
  line-height: 35px;
  position: absolute;
  bottom: 40px;
  right: 20px;
  background-color: #3756d4;
  color: #fff;
  font-size: 20px;
  transition: all .4s;
  .el-icon-top {
    transition: all .4s;
  }
  &:hover {
    cursor: pointer;
    opacity: .88;
  }
  &.active {
    .el-icon-top {
      transform: translateY(-6px);
    }
  }
}
style>

在引用处传入toTop即可显示回到顶部按钮

  

    
{{ item }}
  

横向滚动

接收direction属性，控制滚动方向，默认为y，这里主要通过改变样式实现。

<template>
  <el-scrollbar
    :class="['scroll-bar', {'direction-x': direction === 'x'}]"
    ref="scroll"
    :style="style">
    <slot />
    <div
      v-show="showToTop"
      class="to-top"
      :style="[
        {'background-color': toTopTheme.bgc},
        {'color': toTopTheme.color},
        {'right': toTopPos.right},
        {'bottom': toTopPos.bottom}
      ]"
      @click="handleToTop">
      <i class="el-icon-top">i>
    div>
  el-scrollbar>
template>

<script>
export default {
  props: {
    height: {
      type: String,
      default () {
        return '100%'
      }
    },
    toTop: {
      type: Boolean,
      default () {
        return false
      }
    },
    toTopTheme: {
      type: Object,
      default () {
        return {
          bgc: '',
          color: ''
        }
      }
    },
    toTopPos: {
      type: Object,
      default () {
        return {
          right: '',
          bottom: ''
        }
      }
    },
    direction: {
      type: String,
      default () {
        return 'y'
      }
    }
  },
  data () {
    return {
      showToTop: false
    }
  },
  computed: {
    style () {
      return {
        height: this.height
      }
    }
  },
  mounted () {
    this.toTop && this.$refs.scroll.wrap.addEventListener('scroll', this.scrollFunc)
  },
  methods: {
    scrollFunc (e) {
      const scrollTop = e.target.scrollTop
      if (scrollTop > 80) {
        this.showToTop = true
      } else {
        this.showToTop = false
      }
    },
    handleToTop () {
      // el-scrollbar滚动层为wrap
      this.$refs.scroll.wrap.scrollTo({
        top: 0,
        behavior: 'smooth'
      })
    }
  }
}
script>

<style lang="scss">
.scroll-bar {
  &.direction-x {
    .el-scrollbar__wrap{
      overflow-x: auto !important;
      height: calc(100% + 20px);
      .el-scrollbar__view{
        height: 100%;
      }
    }
  }
  .el-scrollbar__wrap {
    overflow-x: hidden;
  }
}
style>
<style lang="scss" scoped>
.to-top {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  text-align: center;
  line-height: 35px;
  position: absolute;
  bottom: 40px;
  right: 20px;
  background-color: #3756d4;
  color: #fff;
  font-size: 20px;
  transition: all .4s;
  .el-icon-top {
    transition: all .4s;
  }
  &:hover {
    cursor: pointer;
    opacity: .88;
  }
  &.active {
    .el-icon-top {
      transform: translateY(-6px);
    }
  }
}
style>

使用处记得横向超出不换行

<template>
  <div style="width: 400px; height: 400px; margin: 0 auto;">
    <scroll-bar direction="x">
      <ul>
        <li
          v-for="item in 100"
          :key="item">{{ item }}li>
      ul>
    scroll-bar>
  div>
template>

<script>
import ScrollBar from '@/components/ScrollBar'

export default {
  components: {
    ScrollBar
  },
  data () {
    return {

    }
  },
  methods: {
  }
}
script>

<style lang="scss" scoped>
ul {
  display: flex;
  flex-wrap: nowrap;
  li {
    width: 100px;
  }
}
style>

最大高度(完整代码）

接收maxHeight属性，动态内容不设置固定高度时使用，通过给容器el-scrollbar__wrap设置最大高度实现。

<template>
  <el-scrollbar
    :class="['scroll-bar', {'direction-x': direction === 'x'}, {'max-height': maxHeight}]"
    ref="scroll"
    :style="style">
    <slot />
    <div
      v-show="showToTop"
      class="to-top"
      :style="[
        {'background-color': toTopTheme.bgc},
        {'color': toTopTheme.color},
        {'right': toTopPos.right},
        {'bottom': toTopPos.bottom}
      ]"
      @click="handleToTop">
      <i class="el-icon-top">i>
    div>
  el-scrollbar>
template>

<script>
export default {
  props: {
    height: {
      type: String,
      default () {
        return '100%'
      }
    },
    maxHeight: {
      type: String
    },
    toTop: {
      type: Boolean,
      default () {
        return false
      }
    },
    toTopTheme: {
      type: Object,
      default () {
        return {
          bgc: '',
          color: ''
        }
      }
    },
    toTopPos: {
      type: Object,
      default () {
        return {
          right: '',
          bottom: ''
        }
      }
    },
    direction: {
      type: String,
      default () {
        return 'y'
      }
    }
  },
  data () {
    return {
      showToTop: false
    }
  },
  computed: {
    style () {
      return {
        height: this.height,
        '--maxHeight': this.maxHeight || ''
      }
    }
  },
  mounted () {
    this.toTop && this.$refs.scroll.wrap.addEventListener('scroll', this.scrollFunc)
  },
  methods: {
    scrollFunc (e) {
      const scrollTop = e.target.scrollTop
      if (scrollTop > 80) {
        this.showToTop = true
      } else {
        this.showToTop = false
      }
    },
    handleToTop () {
      // el-scrollbar滚动层为wrap
      this.$refs.scroll.wrap.scrollTo({
        top: 0,
        behavior: 'smooth'
      })
    }
  }
}
script>

<style lang="scss">
.scroll-bar {
  &.direction-x {
    .el-scrollbar__wrap{
      overflow-x: auto !important;
      height: calc(100% + 20px);
      .el-scrollbar__view{
        height: 100%;
      }
    }
  }
  &.max-height {
    .el-scrollbar__wrap {
      max-height: var(--maxHeight);
      overflow-x: hidden;
    }
  }
  .el-scrollbar__wrap {
    overflow-x: hidden;
  }
}
style>
<style lang="scss" scoped>
.to-top {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  text-align: center;
  line-height: 35px;
  position: absolute;
  bottom: 40px;
  right: 20px;
  background-color: #3756d4;
  color: #fff;
  font-size: 20px;
  transition: all .4s;
  .el-icon-top {
    transition: all .4s;
  }
  &:hover {
    cursor: pointer;
    opacity: .88;
  }
  &.active {
    .el-icon-top {
      transform: translateY(-6px);
    }
  }
}
style>

引用处设置maxHeight

<template>
  <div style="width: 400px; margin: 0 auto;">
    <scroll-bar maxHeight="200px">
      <ul>
        <li
          v-for="item in 100"
          :key="item">{{ item }}li>
      ul>
    scroll-bar>
  div>
template>

<script>
import ScrollBar from '@/components/ScrollBar'

export default {
  components: {
    ScrollBar
  },
  data () {
    return {

    }
  },
  methods: {
  }
}
script>