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-menu
            router
            active-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()}elseif(store.state.user.id){initMenus(router,store,next,to)}else{next({path:'/',query:{redirect: to.path}});}});exportconstinitMenus=(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.data
                if(responseData.flag){
                    store.state.menu = responseData.data
                    initRoute(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.$ElMessage.error('请求菜单失败')}}})}}constinitRoute=(router,state)=>{constloadView=view=>{//这种引入方式控制台不会报警告// 路由懒加载return()=>import(`@/views/${view}`)};const menus = state.menu
    const 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.$route.path"text-color="#fff"@open=""@close=""><templatev-for="route of this.$store.state.menu"><templatev-if="route.children === null || route.children.length === 0"><!--一级菜单--><templatev-if="!route.isHidden"><el-menu-item:index="route.path"><span>{{route.name}}</span></el-menu-item></template></template><templatev-else><!--二级菜单--><templatev-if="!route.isHidden"><el-sub-menu:index="route.path"><template#title><span>{{route.name}}</span></template><templatev-for="children of route.children"><templatev-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