实现效果：

如上图所示，实现el-tree的基本使用，回显及联调。

1.点击弹框弹出样式，node-key是id,与后端字段名对应

<Dialog v-model="menuVisible" title="菜单分配">
    <el-tree
      :data="treeData"
      show-checkbox
      node-key="menuCode"
      :default-expanded-keys="expandKeys"
      :default-checked-keys="checkedKeys"
      :props="defaultProps"
      title="菜单分配"
      @check="boxCheck"
      ref="treeRef"
    />
    <template #footer>
      <ElButton
        v-if="actionType !== 'detail'"
        type="primary"
        :loading="saveLoading"
        @click="saveMenu"
      >
        {{ t('exampleDemo.save') }}
      </ElButton>
      <ElButton @click="menuVisible = false">{{ t('dialogDemo.close') }}</ElButton>
    </template>
  </Dialog>

2.ref声明，label是文字显示，填写与后端返回数据文字对应的字段名

3.点击按钮方法调用接口，展示数据或回显数据

//菜单分配
const menuAssignment = async (row: any) => {
  console.log(row, '表格数据')
  role1.value = row.roleCode
  menuVisible.value = true
  const res = await getTree()
    .catch(() => {})
    .finally(() => {})
  const res1 = await getMenuList({ roleCode: row.roleCode })
    .catch(() => {})
    .finally(() => {})
  if (res) {
    treeData.value = res.rows
    if (res1) {
      // 回显选中菜单
      let menuIds = res1.rows
      //避免获取不到getNode
      setTimeout(() => {
        menuIds.forEach((item: any) => {
          const node = treeRef.value.getNode(item)
          if (node.isLeaf) {
            treeRef.value.setChecked(item, true)
            chooseKeys.value.push(item)
          }
        })
      }, 100)
    }
  }
}

4.选中数据调用check方法，将选中的子节点和父节点连接起来存放到chooseKeys数组中

const boxCheck = () => {
  let checkedKeys = treeRef.value.getCheckedKeys()
  let halfCheckedKeys = treeRef.value.getHalfCheckedKeys()
  chooseKeys.value = checkedKeys.concat(halfCheckedKeys)
}

5.点保存将数据传到后端（传参根据后端需求更改）

//菜单保存
const saveMenu = async () => {
  // const elTableExpose = await getElTableExpose()
  ElMessageBox.confirm('确定要保存吗?', '提醒', {
    confirmButtonText: '确定',
    cancelButtonText: '取消',
    type: 'warning'
  })
    .then(async () => {
      saveLoading.value = true
      const para = {
        roleCode: unref(role1),
        // ...multipleSelection.value
        rightCodes: chooseKeys.value
      }
      await saveMenuRole(para).finally(() => {
        saveLoading.value = false
      })
      ElMessage({
        type: 'success',
        message: '保存成功'
      })
      getList()
      menuVisible.value = false
    })
    .catch(() => {
      ElMessage({
        type: 'info',
        message: '保存失败'
      })
      menuVisible.value = false
    })
}

最后就完成啦