<div id="app">  <h1>滾動行為</h1>  <ul>    <li><router-link to="/">首頁</router-link></li>    <li><router-link to="/foo">導航</router-link></li>    <li><router-link to="/bar">關于</router-link></li>    <li><router-link to="/bar#an1">紅色頁面</router-link></li>    <li><router-link to="/bar#an2">藍色頁面</router-link></li>  </ul>  <router-view></router-view></div><script>  var Home = {    template:"<div>home</div>"  }  var Foo = {    template:"<div>foo</div>"  }  var Bar = {    template:      `        <div>          bar          <div style="height:500px;background: yellow;"></div>          <p id="an1" style="height:500px;background: red;">紅色頁面</p>          <p id="an2" style="height:300px;background: blue;">藍色頁面</p>        </div>      `  }  var router = new VueRouter({    mode:"history",    //控制滾動位置    scrollBehavior (to, from, savedPosition) {      //判斷如果滾動條的位置存在直接返回到當前位置，否者返回到起點      if (savedPosition) {        return savedPosition      } else {        if (to.hash) {          return {selector: to.hash}        }      }    },    routes:[      {        path:"/",component:Home      },      {        path:"/foo",component:Foo      },      {        path:"/bar",component:Bar      }    ]  });  var vm = new Vue({    el:"#app",    router  });</script>