基于Vue实现封装一个虚拟列表组件

<template>
  <div>
    <div class="virtual-list-md-wrap">
      <hub-virtual-list :allData="data" itemHeight="70" :virtualData.sync="virtualData">
        <div v-for="(item, index) in virtualData" class="item">
         {{ item  }}
         <el-button type="primary" size="mini" plain @click="deleteItem(item)">删除</el-button>
        </div>
      </hub-virtual-list>
    </div>
  </div>
  
</template>
<script>
export default {
  data() {
    return {
      data: [],
      virtualData: []
    }
  },
  created() {
    setTimeout(() => {
      this.addData()
    }, 1000)
  },
  watch: {
  },
  methods: {
    addData() {
      for(let i = 0; i <= 100000; i ++) {
        this.$set(this.data, i, i)
      }
    },
    deleteItem(index) {
      this.data = this.data.filter((item) => item !== index)
    }
  }
}
</script>
<style>
.virtual-list-md-wrap {
  height: 500px;
  background-color: #FFFAF0;
}
.item {
  border-bottom: 1px solid #666;
  padding: 20px;
  text-align: center;
}
</style>

<template>
  <div class="hub-virtual-list">
    <!-- 显示高度 -->
    <div ref="virtualList" class="hub-virtual-list-show-height" @scroll="scrollEvent($event)">
      <!-- 全部高度，撑出滚动条 -->
      <div class="hub-virtual-list-all-height" :style="{height: allHeight + 'px'}"/>
      <!-- 存放显示数据 -->
      <div class="virtual-list" :style="{ transform: getTransform }"/>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.hub-virtual-list {
  height: 100%;
  &-show-height {
    position: relative;
    overflow: auto;
    height: 100%;
    -webkit-overflow-scrolling: touch;
  }
  &-all-height {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    z-index: -1;
    height: auto;
  }
  .virtual-list {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    height: auto;
  }
}
</style>

scrollEvent(e) {
  const scrollTop = this.$refs.virtualList.scrollTop
  // 起始索引 = 滚动距离 / 每项高度
  this.startIndex = Math.floor(scrollTop / this.itemHeight)
  // 结束索引 = 开始索引 + 可见数量
  this.endIndex = this.startIndex + this.visibleCount
  // 偏移量 = 滚动距离
  this.offset = scrollTop - (scrollTop % this.itemHeight)
}

<!-- 显示高度 -->
<div ref="virtualList" class="hub-virtual-list-show-height" @scroll="scrollEvent($event)">
  <!-- 全部高度，撑出滚动条 -->
  <div class="hub-virtual-list-all-height" :style="{height: allHeight + 'px'}"/>
  <!-- 存放显示数据 -->
  <div class="virtual-list" :style="{ transform: getTransform }">
    <!-- 设置插槽 -->
    <slot/> 
  </div>
</div>

scrollEvent(e) {
  const scrollTop = this.$refs.virtualList.scrollTop
  // 起始索引 = 滚动距离 / 每项高度
  this.startIndex = Math.floor(scrollTop / this.itemHeight)
  // 结束索引 = 开始索引 + 可见数量
  this.endIndex = this.startIndex + this.visibleCount
  // 偏移量 = 滚动距离
  this.offset = scrollTop - (scrollTop % this.itemHeight)
  // 同步父组件数据
  this.inVirtualData = this.allData.slice(this.startIndex, this.endIndex)
  this.$emit('update:virtualData', this.inVirtualData)
}

<template>
  <div class="hub-virtual-list">
    <!-- 显示高度 -->
    <div ref="virtualList" class="hub-virtual-list-show-height" @scroll="scrollEvent($event)">
      <!-- 全部高度，撑出滚动条 -->
      <div class="hub-virtual-list-all-height" :style="{height: allHeight + 'px'}"/>
      <!-- 存放显示数据 -->
      <div class="virtual-list" >
        <slot/>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  name: 'hub-virtual-list',
  props: {
    // 全部数据
    allData: {
      type: Array,
      default: () => []
    },
    // 虚拟数据
    virtualData: {
      type: Array,
      default: () => []
    },
    // 每项高度
    itemHeight: {
      type: [Number, String],
      default: '30'
    },
    // 每项样式
    itemStyle: {
      type: Object,
      default: () => {}
    }
  },
  data() {
    return {
      // 起始索引
      startIndex: 0,
      // 结束索引
      endIndex: null,
      // 偏移量，计算滚动条
      offset: 0,
      inVirtualData: []
    }
  },
  computed: {
    // 所有高度
    allHeight() {
      // 每项高度 * 项数
      return this.itemHeight * this.allData.length
    },
    // 可见数量
    visibleCount() {
      // 可见高度 / 每项高度
      return Math.ceil(this.showHeight / this.itemHeight)
    },
    // 显示数据的偏移量
    getTransform() {
      return `translate3d(0, ${this.offset}px, 0)`
    }
  },
  watch: {
    allData: {
      handler() {
        this.inVirtualData = this.allData.slice(this.startIndex, this.endIndex)
        this.$emit('update:virtualData', this.inVirtualData)
      },
      deep: true
    }
  },
  mounted() {
    this.showHeight = this.$el.clientHeight
    this.startIndex = 0
    this.endIndex = this.startIndex + this.visibleCount
  },
  methods: {
    scrollEvent(e) {
      const scrollTop = this.$refs.virtualList.scrollTop
      // 起始索引 = 滚动距离 / 每项高度
      this.startIndex = Math.floor(scrollTop / this.itemHeight)
      // 结束索引 = 开始索引 + 可见数量
      this.endIndex = this.startIndex + this.visibleCount
      // 偏移量 = 滚动距离
      this.offset = scrollTop - (scrollTop % this.itemHeight)
      // 同步父组件数据
      this.inVirtualData = this.allData.slice(this.startIndex, this.endIndex)
      this.$emit('update:virtualData', this.inVirtualData)
    }
  }
}
</script>

<style lang="scss" scoped>
.hub-virtual-list {
  height: 100%;
  &-show-height {
    position: relative;
    overflow: auto;
    height: 100%;
    -webkit-overflow-scrolling: touch;
  }
  &-all-height {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    z-index: -1;
    height: auto;
  }
  .virtual-list {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    height: auto;
  }
}
</style>