el-checkbox实现全选，反选，单选

<template>
  <div class="box">
    <el-checkbox v-model="checkAll" :indeterminate="isIndeterminate" @change="onAllSelectChange"> 全选</el-checkbox>
    <div class="item" v-for="(item,index) in list" :key="index">
      <el-checkbox v-model="item.checked" @change="selectChangeItem" style="margin-top:15px" />
      <div class="main">
        <div class="title">{{item.title}}</div>
        <div class="content">{{item.content}}</div>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  data () {
    return {
      isIndeterminate: null,
      checkAll: false,
      list: [
        {
          title: "学不会学不会学不会学不会",
          content: '学不会学不会学不会学不会学不会学不会学不会学不会学不会',
          checked: false
        },
        {
          title: "学不会学不会学不会学不会",
          content: '学不会学不会学不会学不会学不会学不会学不会学不会学不会',
          checked: false
        },
        {
          title: "学不会学不会学不会学不会",
          content: '学不会学不会学不会学不会学不会学不会学不会学不会学不会',
          checked: false
        },
        {
          title: "学不会学不会学不会学不会",
          content: '学不会学不会学不会学不会学不会学不会学不会学不会学不会',
          checked: false
        }
      ],
      checkList: [] // 勾选的数据
    }
  },
  methods: {
    // 全选
    onAllSelectChange () {
      this.list.forEach(item => {
        // 全选了
        if (this.checkAll) {
          item.checked = true
          this.isIndeterminate = false
          this.checkList = this.list
          // 取消全选
        } else {
          item.checked = false
          this.isIndeterminate = null
          this.checkList = []
        }
      })
    },
    // 单选
    selectChangeItem () {
      const check = this.list.every(item => item.checked)
      // 单选有一个未勾选
      if (!check) {
        this.isIndeterminate = true
      } else {
        // 单选都勾选了
        this.isIndeterminate = null
        this.checkAll = true
      }
      // 单选都未勾选
      const flag = this.list.map(item => item.checked).some(item => item)
      if (!flag) {
        this.checkAll = false
        this.isIndeterminate = null
      }
      // 勾选的数据
      this.checkList = this.list.filter(item => item.checked)
    }
  }
}
</script>

<style lang="less" scoped>
.box {
  margin: 30px;
}
.item {
  padding: 20px;
  border: 1px solid greenyellow;
  background: #fff;
  display: flex;
  .main {
    margin-left: 20px;
  }
}
</style>