<el-tree :props="props" :load="loadNode" lazy />
<script lang="ts" setup>
const props = {
  label: 'name',
  children: 'zones',
  isLeaf: (data, node) => {
    // (关键代码)这里是为了判断没有子级不显示展开图标
    if (data.hasChildren) {
      return false
    } else {
      return true
    }
  }
}
</script>