element-UI,根据后台数据、动态生成el-checkbox-group，点击提交获取绑定checked项以及实现显示默认checked项

<template>
  <div id="Demo">
    <el-form ref="form" label-width="100px">
      <el-form-item label="设备名称">
       <div
          class="check-group"
          v-for="(item, index) in equipments"
          :key="index">
          <el-tag>{{item.menu}}</el-tag>
          <el-checkbox-group
            v-model="checkedEquipments[index]"
            @change="handleChange(item.id)">
            {{checkedEquipments[index]}}
            <el-checkbox
              v-for="data in item.childMenu"
              :label="data.id"
              :key="data.menu">
              {{data.menu}}
            </el-checkbox>
          </el-checkbox-group>
        </div>
      </el-form-item>
    </el-form>
  </div>
</template>
export default {
    data() {
      return {
        checkedEquipments: [], //随意修改后的checked项（即要传到后台的变更数据）
        equipments: [   // 所有数据
          {
            id: ‘1‘,
            menu: ‘设备1‘,
            childMenu: [{
                id: ‘1-1‘,
                menu: ‘暖通一‘
              }, {
                id: ‘1-2‘,
                menu: ‘照明一‘
              }, {
                id: ‘1-3‘,
                menu: ‘取暖一‘
              }, {
                id: ‘1-4‘,
                menu: ‘应急一‘
              }
            ]
          },
          {
            id: ‘2‘,
            menu: ‘设备2‘,
            childMenu: [
              {
                id: ‘2-1‘,
                menu: ‘暖通二‘
              }, {
                id: ‘2-2‘,
                menu: ‘照明二‘
              }, {
                id: ‘2-3‘,
                menu: ‘取暖二‘
              }, {
                id: ‘2-4‘,
                menu: ‘应急二‘
              }
            ]
          }
        ],
        checkEquip: [  //模拟后台获取的数据（各el-checkbox-group默认checked项）
          {
            id: ‘1‘,
            menu: ‘设备1‘,
            childMenu: [
              {
                id: ‘1-1‘,
                menu: ‘暖通一‘
              }, {
                id: ‘1-2‘,
                menu: ‘照明一‘
              }
            ]
          }, {
            id: ‘2‘,
            menu: ‘设备2‘,
            childMenu: []
          }
        ]
      };
    },
    methods: {
      handleChange () {
        this.checkEquipArr = []
        let arr = this.checkedEquipments
        for (let i = 0; i < arr.length; i ++) {
          let equipment = arr[i]
          if (equipment.length > 0) {
            let obj = {
              id: this.equipments[i].id,
              equips: []
            }
            for (let j = 0; j < equipment.length; j++) {
              obj.equips.push(equipment[j])
            }
            this.checkEquipArr.push(obj)
          }
        }
        console.log(this.checkEquipArr);
      }
    },
    created () {
      // 初始化默认选中状态
      for (let i = 0; i < this.checkEquip.length; i++) {
        let checkArr = []
        let item = this.checkEquip[i].childMenu
        if (item.length === 0) {
          this.checkedEquipments.push([])
        }else {
          for (let j = 0; j < item.length; j ++) {
            checkArr.push(item[j].id)
          }
          this.checkedEquipments.push(checkArr)
        }
      }
      console.log(this.checkedEquipments);
    }
  };