el-menu动态加载路由，菜单的解决方案

先看需要实现的效果

这里有一级也有二级菜单，注意二级菜单的父目录（”选项设置“点击不会跳转，只是展开目录），然后点击去详情页，需要跳到一个隐藏的路由，不在菜单展示的路由
还有一点要注意，就是这里有两个router-view，整个页面是一个router-view，可以由LoginView和HomeView替换（当前看到的页面），而HomeView下又有一个router-view，需要用来展示部门，系统，超时，员工设置，不合格品列表和不合格品详情页。

以上的信息均需要在数据库的表中体现
先看看直接写在代码里需要哪些操作

const routes = [{path: '',name: 'login',component: LoginView,},{component: HomeView,children: [{path: '/home',name: '不合格品列表',component: BelowStandard},{path: '/product/:id',name: '不合格品详情',component: BelowStandardDetail}]},{component: HomeView,name: '选项设置',children: [{path: '/employee',name: '员工设置',component: EmployeeConfig,},{path: '/department',name: '部门设置',component: DepartmentConfig},{path: '/system',name: '系统设置',component: SystemConfig},{path: '/warn',name: '超时提醒',component: WarmConfig}]},{component: HomeView,children: [{path: '/statistics',name: '统计',component: DailyStatistics}]},{component: HomeView,children: [{path: '/log',name: '日志管理',component: LogManager}]},]

这是路由，当要动态从数据库加载时，就不能写在这

<el-menurouteractive-text-color="#ffd04b"background-color="#000"class="el-menu-vertical-demo":default-active="this.$route.path"text-color="#fff"@open=""@close=""><el-menu-item index="/home"><template #title>不合格品列表</template></el-menu-item><el-sub-menu index="/subMenuConfig"><template #title>选项设置</template><el-menu-item index="/department">部门设置</el-menu-item><el-menu-item index="/system">系统设置</el-menu-item><el-menu-item index="/warn">超时设置</el-menu-item><el-menu-item index="/employee">员工设置</el-menu-item></el-sub-menu><el-menu-item index="/statistics"><span>统计</span></el-menu-item><el-menu-item index="/log"><span>日志管理</span></el-menu-item></el-menu>

这是el-menu开启了路由功能，所以能跳转路由，当动态加载的时候，这部分需要改造成v-for

数据库

说明：parent_id为0的即是一级目录，但是一级目录里一部分可以直接展示界面，一部分是展开二级目录，我这是以component字段为home/HomeView.vue来区分是展示二级目录。

现在开始写后端程序，返回菜单的json格式数据。

List<Menu> menuList = menuMapper.getMenuByUserId(UserUtils.getLoginUser().getId());//根据ParentId分组Map<Integer, List<Menu>> map = menuList.stream().collect(Collectors.groupingBy(Menu::getParentId, TreeMap::new,Collectors.toList()));List<Menu> menus = map.get(0);//一级菜单menus.forEach(menu->{//给有二级菜单的目录设置children属性List<Menu> children = map.get(menu.getId());menu.setChildren(children);});return menus;

从数据库查询到的数据格式如图，然后分一级二级菜单处理后，再返回前端

[{"name": "不合格品列表","path": "/home","component": "product/BelowStandard.vue","orderNum": 1,"parentId": 0,"isHidden": false,"children": null},{"name": "选项设置","path": "/subMenuConfig","component": "home/HomeView.vue","orderNum": 2,"parentId": 0,"isHidden": false,"children": [{"name": "员工设置","path": "/employee","component": "config/EmployeeConfig.vue","orderNum": 1,"parentId": 2,"isHidden": false,"children": null},{"name": "部门设置","path": "/department","component": "config/DepartmentConfig.vue","orderNum": 2,"parentId": 2,"isHidden": false,"children": null},{"name": "系统设置","path": "/system","component": "config/SystemConfig.vue","orderNum": 3,"parentId": 2,"isHidden": false,"children": null},{"name": "超时提醒","path": "/warn","component": "config/WarmConfig.vue","orderNum": 4,"parentId": 2,"isHidden": false,"children": null}]},{"name": "统计","path": "/statistics","component": "statistics/DailyStatistics.vue","orderNum": 3,"parentId": 0,"isHidden": false,"children": null},{"name": "日志管理","path": "/log","component": "log/LogManager.vue","orderNum": 4,"parentId": 0,"isHidden": false,"children": null},{"name": "不合格品详情","path": "/product/:id","component": "product/BelowStandardDetail.vue","orderNum": 5,"parentId": 0,"isHidden": true,"children": null}]

前端得到数据之后进行处理，再添加到路由，过程中遇到一个问题，vue-router4版本去掉addRoutes换成addRoute带来的问题困扰我很久，详情可以查看另一篇笔记：
第一次push路由不匹配

初始化路由：

router.beforeEach((to, from, next) => {//配置路由守卫if(to.path==='/'){next()}else if(store.state.user.id){initMenus(router,store,next,to)}else{next({ path: '/',query: {redirect: to.path}});}});export const initMenus = (router, store,next,to) => {//按F5刷新的话vuex里的会被清空，长度变为0if (store.state.menu !== null) {next()}else {axios.get("/menu").then(response => {if (response) {let responseData = response.dataif (responseData.flag) {store.state.menu = responseData.datainitRoute(router,store.state)next({...to,replace:true})//解决router4版本的第一次路由不匹配问题} else {this.$ElMessage.error('请求菜单失败')}}})}}const initRoute = (router,state)=> {const loadView = view => {//这种引入方式控制台不会报警告// 路由懒加载return () => import(`@/views/${view}`)};const menus = state.menuconst firstLevelMenu = {children: [],component: loadView('home/HomeView.vue')}menus.forEach(menu=>{menu.component = loadView(menu.component)if(menu.children === null || menu.children.length === 0){firstLevelMenu.children.push(menu)}else{menu.children.forEach(children=>{children.component = loadView(children.component)})router.addRoute(menu)}})router.addRoute(firstLevelMenu)}

完成这些配置之后，路由就能动态加载了，然后取出vuex中存储的menu生成el-menu

vuex中菜单大致如图

<el-menurouteractive-text-color="#ffd04b"background-color="#000"class="el-menu-vertical-demo":default-active="this.$route.path"text-color="#fff"@open=""@close=""><template v-for="route of this.$store.state.menu"><template v-if="route.children === null || route.children.length === 0"><template v-if="!route.isHidden"><el-menu-item :index = "route.path"><span>{{route.name}}</span></el-menu-item></template></template><template v-else><template v-if="!route.isHidden"><el-sub-menu :index = "route.path"><template #title><span>{{route.name}}</span></template><template v-for="children of route.children"><template v-if="!children.isHidden"><el-menu-item :index = "children.path"><span>{{children.name}}</span></el-menu-item></template></template></el-sub-menu></template></template></template></el-menu>

实现效果展示