vue项目element-ui级联选择器el-cascader回显的问题及解决

   /*
    * el-cascader递归获取父级id
    * @param  list 数据列表
    * @param  id 后端返回的id
    * propsCascader 是el-cascader props属性
    **/
    getParentsById(list, id) {
      for (let i in list) {
        if (list[i][this.propsCascader.value || 'value'] == id) {
          return [list[i][this.propsCascader.value || 'value']]
        }
        if (list[i].children) {
          let node = this.getParentsById(list[i].children, id)
          if (node !== undefined) {
            // 追加父节点
            node.unshift(list[i][this.propsCascader.value || 'value'])
            return node
          }
        }
      }
    },

<el-cascader
              style="width:97%;margin:5px 0;"
              v-model="dataInfo2"
              :options="subjects"
              :props="defaultProps"
              @change="handleChange"
              placeholder="请选择数据表"
              size="small">
</el-cascader>
updateChart(id) {
      this.$http.get('url?id='+id)
        .then(res => {
          if (res.data.success === true) {
            this.dataTableId = res.data.data.dataTableId
            this.dragTo.values = res.data.data.dragTo
            this.$refs.hottable.editShowTableMe(res.data.data)
            this.$http.post('url', {id: this.dataTableId})
              .then(response => {
                this.dataInfo2 = [response.data.data[0].directoryId,this.dataTableId]
                this.dragFrom.measures = []
                this.dragFrom.measures = response.data.data[0].design.schema.measure
                this.deleteChecked()
              })
              .catch(function(error) {
                console.log(error)
              })
          }
        })
        .catch(err => {
          console.log(err)
        })
    },
    deleteChecked() {
      var arr = []
      for (let i = 0; i < this.dragFrom.measures.length; i++) {
        for (let j = 0; j < this.dragTo.values.length; j++) {
          if (
            this.dragFrom.measures[i].column === this.dragTo.values[j].column
          ) {
            arr.push(i)
          }
        }
      }
      for (var k = 0; k < arr.length; k++) {
        if (k == 0) {
          this.dragFrom.measures.splice(arr[k], 1)   //删除arr[0],删除一个
        } else {
          this.dragFrom.measures.splice(arr[k] - k, 1)   //删除arr[0],删除一个，这样判断的意思是一直从第一个开始删除
        }
      }
},