正常导入import {NavMenu} from 'element-ui';会报错

因此要

import {Menu,Submenu, MenuItem,MenuItemGroup} from 'element-ui';

Vue.use(Menu)

Vue.use(Submenu)

Vue.use(MenuItem)

Vue.use(MenuItemGroup)

参考 https://blog.csdn.net/qq_41556706/article/details/81167170