element-ui中实现tree子节点部分选中时父节点也选中

 let zi = this.$refs.tree.getCheckedKeys()//返回选中子节点的key
 let fu =this.$refs.tree.getHalfCheckedKeys()//返回选中子节点的父节点的key
 let new1 = zi.concat(fu)

 <el-tree
   :data="list.data"
   show-checkbox
   node-key="id"
   :props="defaultProps"
   :default-expand-all="list.isExpand"
   v-loading="list.loading"
   ref="tree"
   @check-change="checkChange">
 </el-tree>

export default {
  data () {
    return {
      list: {
        data: [],
        loading: false,
        isExpand: true
      },
      defaultProps: {
        children: 'children',
        label: 'name'
      },
      loading:false
    }
  },
  methods: {
    defaultChecked () { // 默认选中
      this.$nextTick(() => {
        const arr = []
        this.menus.forEach(item => {
          if (!this.$refs.tree.getNode(item.id).childNodes || !this.$refs.tree.getNode(item.id).childNodes.length) {
            arr.push(item.id)
          }
        })
        this.$refs.tree.setCheckedKeys(arr)
      })
    },
  }
}