<template><div class=''>  <input type="text" v-model="name" />  <input type="password" v-model="password" />  <button type="primary" @click="submitForm"><router-link :to="{path:'/'}">提交</router-link></button></div></template><script>import axios from 'axios'; export default {  data(){    return{    name:'',    password:'',    }  },  methods:{  submitForm:function(){  var params = new URLSearchParams();  params.append('name', this.name);  params.append('password',this.password);    axios({    method: 'post',    url: '/api/bbb.php',    data:params    }).then((resp)=>{      sessionStorage.setItem('token',resp.status)// localStorage      //以key value的形式將值存放到sessionStorage中。      console.log(resp);      }).catch((error)=>{        console.log(error); })   }  } }</script>

  {   path: '/',   name: 'HelloWorld',   component: HelloWorld,   meta:{requireAuth:true}  },

router.beforeEach((to, from, next) => { console.log(to); console.log(from); console.log( sessionStorage.getItem('token')) if (to.meta.requireAuth) { // 判斷該路由是否需要登錄權限  if(sessionStorage.getItem('token')){ //判斷sessionStorage是否存在token   alert("已經登錄了")   next();  }else{   //防止死循環   alert("暫時未登錄")   if (to.path === '/login') {    next();    return   }else{     next({     path: '/login',   }); }  } } else {  next(); } /*如果本地 存在 token 則 不允許直接跳轉到 登錄頁面*/ if(to.fullPath == "/login"){  if(localStorage.getItem('token')){   next({    path:from.fullPath   });  }else {   next();  } }});