<treeselect :placeholder="$t('taskManage.lockTask.selDeptId')"
               :options="deptTree"
               :normalizer="normalizer"
               v-model="formData.deptId"
               @select="selectDepart">
</treeselect>

// 获取当前选中部门的名称
selectDepart(val) {
   console.log('selectDepart', val)
   this.formData.deptName = val.name
}

if (child.checked && (!leafOnly || leafOnly && child.isLeaf)) {
     checkedNodes.push(child.data);
    }

if ((child.checked || child.indeterminate) && (!leafOnly || leafOnly && child.isLeaf)) {
     checkedNodes.push(child.data);
    }

 methods: {
   getCheckedNodes() {
    var rad=''
    var ridsa = this.$refs.tree.getCheckedKeys().join(',')// 获取当前的选中的数据[数组] -id, 把数组转换成字符串
    var ridsb = this.$refs.tree.getCheckedNodes()// 获取当前的选中的数据{对象}
    ridsb.forEach(ids=>{//获取选中的所有的父级id
     rad+=','+ids.pid
    })
    rad=rad.substr(1) // 删除字符串前面的','
    var rids=rad+','+ridsa
    var arr=rids.split(',')// 把字符串转换成数组
    arr=[...new Set(arr)]; // 数组去重
    rids=arr.join(',')// 把数组转换成字符串
    console.log(rids)
   }
  }

<template>
 <div>
  <el-tree
 :data="data2"
 show-checkbox
 default-expand-all
 node-key="id"
 ref="tree"
 highlight-current
 :props="defaultProps">
</el-tree>

<div class="buttons">
 <el-button @click="getCheckedNodes">获取</el-button>
 <el-button @click="resetChecked">清空</el-button>
</div>
 </div>
 </template>
 <script>
 export default {
  methods: {
   getCheckedNodes() {
    var rad=''
    var ridsa = this.$refs.tree.getCheckedKeys().join(',')// 获取当前的选中的数据[数组] -id, 把数组转换成字符串
    var ridsb = this.$refs.tree.getCheckedNodes()// 获取当前的选中的数据{对象}
    ridsb.forEach(ids=>{//获取选中的所有的父级id
     rad+=','+ids.pid
    })
    rad=rad.substr(1) // 删除字符串前面的','
    var rids=rad+','+ridsa
    var arr=rids.split(',')// 把字符串转换成数组
    arr=[...new Set(arr)]; // 数组去重
    rids=arr.join(',')// 把数组转换成字符串
    console.log(rids)
   },
   resetChecked() {
    this.$refs.tree.setCheckedKeys([]);
   }
  },

  data() {
   return {
    data2: [{
     pid:0,
     path:xxxx,
     id: 1,
     label: '一级 1',
     children: [{
      pid:1,
      path:xxxx,
      id: 11,
      label: '二级 1-1'
     },
     {
      pid:1,
      path:xxxx,
      id: 12,
      label: '二级 1-2'
     },
     {
      pid:1,
      path:xxxx,
      id: 13,
      label: '二级 1-3'
     }]
    }],
    defaultProps: {
     children: 'children',
     label: 'label'
    }
   };
  }
 };
</script>
 </script>
 <style scoped>
 </style>

{
 "data": [
   {
     "id": 30,
     "path": xxxx,
     "children": [
       {
         "id": 101,
         "path": xxxx,
         "children": [
           {
             "id": 104,
             "path": xxxx,
             "children": [
               {
                 "id": 105,
                 "path": xxxx
               }
             ]
           }
         ]
       }
     ]
   }
 ],
 "meta": {
   "msg": "获取成功",
   "status": 200
 }
}