為什麼要用二級和三級路由？

當專案中 有多個 <router-view> 時，就必須使用分級路由；

如果路由不分級，又有多個 <router-view> ,全部都是定義為一級路由，那麼專案中的  <router-view> 的內容顯示就會混亂；這是不友好的；

如果對路由進行分級，那麼當觸發某個二級或三級路由時，此路由就會將對應元件內容傳給自己的父級路由元件裡面的 <router-view>，這樣就不會混亂；

一級路由被觸發時，自然會找自己所註冊的根元件的<router-view>

二級路由

為一級路由新增一個 children 屬性陣列，並將二級路由放入；

path 屬性 決定 跳轉後 url 位址列的的顯示

//main.js
//一級路由
import About from './components/about/About'


//二級路由
import Contact from './components/about/Contact'
import Delivery from './components/about/Delivery'
import History from './components/about/History'
import OrderingGuide from './components/about/OrderingGuide'

const router= new VueRouter({
  routes:[
    {path:'/about',name:'about',component:About,children:[
        {path:'/about/contsssssssssssssssact',name:'contactLink',component:Contact},
        {path:'/history',name:'historyLink',component:History},
        {path:'/',name:'deliveryLink',component:Delivery},
        {path:'/orderingGuide',name:'orderingGuideLink',component:OrderingGuide},
      ]},
    {path:'*',redirect:'/'}
  ],
  mode:"history"
});
 

三級路由

和二級路由差不多

const router= new VueRouter({
  routes:[
    {path:'/',name:'home',component:Home},
    {path:'/menu',name:'menu',component:Menu},
    {path:'/admin',name:'admin',component:Admin},
    {path:'/about',name:'about',component:About,redirect: {name:'contactLink'},children:[   //二級路由
        {path:'/about/contact',name:'contactLink',component:Contact},
        {path:'/history',name:'historyLink',component:History},
        {path:'/delivery',name:'deliveryLink',component:Delivery},
        {path:'/orderingGuide',name:'orderingGuideLink',component:OrderingGuide,redirect:{name:'phonelink'},children: [  //三級路由
            {path:'/phone',name:'phonelink',component:Phone},
            {path:'/name',name:'namelink',component:Name}
          ]},
      ]},
    {path:'/login',name:'login',component:Login},
    {path:'/register',name:'register',component:Register},
    {path:'*',redirect:'/'}
  ],
  mode:"history"
});