vue实现超过两行显示展开收起

基于vue-cli2，sass，vant（ui组件）：https://youzan.github.io/vant/#/zh-CN/home

具体代码如下：

<template>
  <div>
    <div class="group">
      <div class="text more" ref="more">
        占位
      </div>
      <div class="list" v-for="(item, index) in historyList" :key="index">
        <van-row>
          <van-col span="12">{{ item.version }}</van-col>
          <van-col class="t_right l_text" span="12">{{ item.time }}</van-col>
        </van-row>
        <div class="l_title">{{ item.title }}</div>
        <div
          class="text"
          ref="textContainer"
          :class="{ retract: item.status }"
          :style="{ 'max-height': item.status ? textHeight : '' }"
        >
          {{ item.content }}
        </div>
        <span
          v-if="item.status !== null"
          class="link"
          @click="more(index)"
          >{{ item.status ? "展开" : "收起" }}</span
        >
      </div>
    </div>
  </div>
</template>
<script>
export default {
  data () {
    return {
      textHeight: '',
      historyList: [
        {
          version: '7.1.4',
          title: '本次更新',
          content:
            '-听模块新增“文章难度分析”功能~,为你分析文章中词汇、语速等难度，推荐;-听模块新增“文章难度分析”功能~,为你分析文章中词汇、语速等难度，推荐',
          time: '2周前'
        },
        {
          version: '7.1.4',
          title: '本次更新',
          content:
            '-听模块新增“文章难度分析”功能~,为你分析文章中词汇、语速等难度，推荐',
          time: '5周前'
        },
        {
          version: '7.1.4',
          title: '本次更新',
          content:
            '-听模块新增“文章难度分析”功能~,为你分析文章中词汇、语速等难度，推荐;-听模块新增“文章难度分析”功能~,为你分析文章中词汇、语速等难度，推荐',
          time: '6周前'
        },
        {
          version: '7.1.4',
          title: '本次更新',
          content:
            '-听模块新增“文章难度分析”功能~,为你分析文章中词汇、语速等难度，推荐',
          time: '9周前'
        }
      ]
    }
  },
  mounted () {
    this.historyList.forEach((ele, index) => {
      this.$set(
        this.historyList,
        index,
        Object.assign({}, ele, { status: null })
      )
    })
    // DOM 加载完执行
    this.$nextTick(() => {
      this.calculateText()
      //console.log(this.historyList)
    })

    window.onresize = () => {
      this.historyList.forEach((ele, index) => {
        this.$set(
          this.historyList,
          index,
          Object.assign({}, ele, { status: null })
        )
      })
      setTimeout(() => {
        this.calculateText()
      }, 0)
    }
  },
  methods: {
    // 计算文字 显示展开 收起
    calculateText () {
      // 获取一行文字的height 计算当前文字比较列表文字
      let oneHeight = this.$refs.more.scrollHeight
      let twoHeight = oneHeight * 2 || 40
      this.textHeight = `${twoHeight}px`
      let txtDom = this.$refs.textContainer
      for (let i = 0; i < txtDom.length; i++) {
        let curHeight = txtDom[i].offsetHeight
        if (curHeight > twoHeight) {
          this.$set(
            this.historyList,
            i,
            Object.assign({}, this.historyList[i], { status: true })
          )
        } else {
          this.$set(
            this.historyList,
            i,
            Object.assign({}, this.historyList[i], { status: null })
          )
        }
      }
    },
    more (index) {
      this.historyList[index].status = !this.historyList[index].status
    }
  }
}
</script>
<style lang="scss" scoped>
.group {
  .list {
    padding: 5px 0;
    border-bottom: 1px solid #eaeaea;
  }
  .text {
    position: relative;
    color: #000;
    font-size: 14px;
  }
  .more {
    visibility: hidden;
  }
  .link {
    font-size: 12px;
    color: #2d95fe;
  }
  .retract {
    position: relative;
    overflow: hidden;
  }

  .retract:after {
    content: "...";
    position: absolute;
    bottom: 0;
    right: 2px;
    width: 25px;
    padding-left: 25px;
    background: linear-gradient(to right, transparent, #fff 45%);
  }
}
</style>