Vue之beforeEach非登录不能访问的实现（代码亲测）

<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的形式将值存放到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) { // 判断该路由是否需要登录权限
  if(sessionStorage.getItem('token')){ //判断sessionStorage是否存在token
   alert("已经登录了")
   next();
  }else{
   //防止死循环
   alert("暂时未登录")
   if (to.path === '/login') {
    next();
    return
   }else{
     next({
     path: '/login',
   });
 }
  }
 }
 else {
  next();
 }
 /*如果本地 存在 token 则 不允许直接跳转到 登录页面*/
 if(to.fullPath == "/login"){
  if(localStorage.getItem('token')){
   next({
    path:from.fullPath
   });
  }else {
   next();
  }
 }
});