el-checkbox的基本使用，避坑指南

使用el-checkbox勾选出现的问题：全选不生效，全选后底下的勾选不能回显

有问题的代码

<template>
  <div>
    <el-checkbox
      class="all_t"
      :indeterminate="isIndeterminate"
      v-model="checkAll"
      @change="handleCheckAllChangeSales"
      >全选</el-checkbox
    >
    <el-checkbox-group
      v-model="checkeds"
      @change="handleCheckedColumnChangeSales"
    >
      <el-checkbox
        v-for="(item,index) in detailsList"
        :label="item.title"
        :key="index"
        >{{ item.title }}</el-checkbox
      >
    </el-checkbox-group>
  </div>
</template>

    
    <script>
  export default {
    name: 'demo',
    data() {
      return {
        checkAll: false,
        checkeds: [], // 已选数据
        names: [], // 默认所有数据
        isIndeterminate: false, // 全选框是否在勾选状态
        detailsList: [
         {
	           "title": "销量",
	           "values": [
		           "0",
		           "5"
	          ]
           },
           {
	           "title": "销售额",
	           "values": [
		           "8",
		           "1"
           		]
           },
           {
	           "title": "订单量",
	           "values": [
		           "3",
		           "9"
           		]
           },
           {
	           "title": "退款量",
	           "values": [
		           "0",
		           "0"
           		]
           }
         ]
      }
    },
    created() {
      this.names = this.detailsList
    },
    methods: {
      handleCheckAllChangeSales(val) {
        this.checkeds = val ? this.detailsList : [];
        this.isIndeterminate = false;
      },
      handleCheckedColumnChangeSales(value) {
        let checkedCount = value.length
        this.checkAll = checkedCount === this.names.length
        this.isIndeterminate = checkedCount > 0 && checkedCount < this.names.length
      }
    }
  };
</script>

勾选出现的问题：全选不生效，全选后底下的勾选不能回显，排查问题中发现打印this.checkeds能得到数据，全选和反选数据都能得到。
一开始认为是结构中key的渲染，但是试过后发现 :key="index"还是:key="item.title"都不会影响回显。

仔细阅读官网发现this.checkedCities的数据结构不能那么复杂

所以我在handleCheckAllChangeSales方法中把过滤原来的this.detailsList 数，当全选时赋值给this.checkeds

this.checkeds打印出来这个值是这种结构

最终实现效果

所有代码

<template>
   <div>
     <el-checkbox
       class="all_t"
       :indeterminate="isIndeterminate"
       v-model="checkAll"
       @change="handleCheckAllChangeSales"
       >全选</el-checkbox
     >
     <el-checkbox-group
       v-model="checkeds"
       @change="handleCheckedColumnChangeSales"
     >
       <el-checkbox
         v-for="(item) in detailsList"
         :label="item.title"
         :key="item.title"
         >{{ item.title }}</el-checkbox
       >
     </el-checkbox-group>
   </div>
</template>

<script>
  export default {
    name: 'demo',
    data() {
      return {
        checkAll: false,
        checkeds: [], // 已选数据
        names: [], // 默认所有数据
        isIndeterminate: false, // 全选框是否在勾选状态
        detailsList: [
         {
	           "title": "销量",
	           "values": [
		           "0",
		           "5"
	          ]
           },
           {
	           "title": "销售额",
	           "values": [
		           "8",
		           "1"
           		]
           },
           {
	           "title": "订单量",
	           "values": [
		           "3",
		           "9"
           		]
           },
           {
	           "title": "退款量",
	           "values": [
		           "0",
		           "0"
           		]
           }
         ]
      }
    },
    created() {
      this.names = this.detailsList
    },
    methods: {
      handleCheckAllChangeSales(val) {
        var checkedsItem = val ? this.detailsList : []
        if (checkedsItem.length > 0) {
          checkedsItem.map(item => {
            this.checkeds.push(item.title)
          })
        } else {
          this.checkeds = []
        }
        this.isIndeterminate = false
      },
      handleCheckedColumnChangeSales(value) {
        let checkedCount = value.length
        this.checkAll = checkedCount === this.names.length
        this.isIndeterminate = checkedCount > 0 && checkedCount < this.names.length
      }
    }
  };
</script>