vue ElementUI级联选择器回显问题解决

{
  "label": "浙江省",
  "value": 12321
  "children": [{
      "label": "杭州市",
      "value": 4565
   }]
}

<el-cascader
  v-model='data'
  :props='cascadeProps'
  :options='cascadeOptions'
  filterable
  ></el-cascader>

cascadeProps: {
  multiple: true,
    checkStrictly: true,
      // 启用懒加载
      lazy: true,
        // 远程数据访问
        lazyLoad: async (node, resolve) => {
          const { data, level} = node
          const parentCode = level === 0 ? '000' : data.nodeCode
          const nodes = await this.getRemoteData(parentCode, level)
          // 去除重复节点
          let nodeFilter = nodes.filter(n => {
            if (!this.optionList.includes(n.value)) {
              return n
            }
          })
          resolve(nodeFilter)
        },
},

getRemoteData(parentCode, level) {
  return new Promise((resolve, reject) => {
    getDistrictData({ parentCode }).then((res) => {
      resolve(this.formatData(res.data, level))
    })
  })
},

  formatData(data, level) {
    let districtType = ''
    switch (level) {
      case 0:
        districtType = 'province'
        break
      case 1:
        districtType = 'city'
        break
      case 2:
        districtType = 'district'
        break
      default:
        break
    }
    return data.map((item) => {
      return {
        districtType,
        nodeCode: item.nodeCode,
        value: item.districtId,
        label: item.name,
        leaf: level >= 2,
      }
    })
  },