{
 "error_code": 0,
 "data": [{
   "id": '1',
   "usertitle": "管理員",
   "username": "admin",
   "password": "123456",
   "token": "@date(T)",
  },
  {
   "id": '2',
   "usertitle": "超級(jí)管理員",
   "username": "root",
   "password": "root",
   "token": "@date(T)",
  }
 ]
}

<template>
<div>
  <p>用戶(hù)名：<input type='text' v-model="userName"></p>
  <p>密碼：<input type='text' v-model="passWord"></p>
  <button @click="login()">登錄</button>
</div>
</template>
<script>
 export default {
  data() {
    return {
     userName:'root',
     passWord:'root'
    }
  }
}
</script>

 login(){
    const self = this;
    axios.get('https://easy-mock.com/mock/5c7cd0f89d0184e94358d/museum/login').then(response=>{
     var res =response.data.data,
       len = res.length,
       userNameArr= [],
       passWordArr= [],
       ses= window.sessionStorage; 
     // 拿到所有的username
     for(var i=0; i<len; i++){
      userNameArr.push(res[i].username);
      passWordArr.push(res[i].password);
     }
     console.log(userNameArr, passWordArr);
     if(userNameArr.indexOf(this.userName) === -1){
       alert('賬號(hào)不存在！');
     }else{
      var index = userNameArr.indexOf(this.userName);
      if(passWordArr[index] === this.passWord){
       // 把token放在sessionStorage中
       ses.setItem('data', res[index].token);
       this.$parent.$data.userTitle = res[index].usertitle;
       //驗(yàn)證成功進(jìn)入首頁(yè)
       this.startHacking ('登錄成功！');
       //跳轉(zhuǎn)到首頁(yè)
       this.$router.push('/index');
       // console.log(this.$router);
      }else{
       alert('密碼錯(cuò)誤！')
      }
     }
    }).catch(err=>{
     console.log('連接數(shù)據(jù)庫(kù)失??！')
    })
   }

  {
   path: '/',
   name: 'login',
   component: login,
   meta:{
    needLogin: false
   }
  },
  {
   path: '/index',
   name: 'index',
   component: index,
   meta:{
    needLogin: true
   }
  }

//路由守衛(wèi)
router.beforeEach((to, from, next)=>{
  //路由中設(shè)置的needLogin字段就在to當(dāng)中 
  if(window.sessionStorage.data){
   console.log(window.sessionStorage);
   // console.log(to.path) //每次跳轉(zhuǎn)的路徑
   if(to.path === '/'){
    //登錄狀態(tài)下 訪(fǎng)問(wèn)login.vue頁(yè)面 會(huì)跳到index.vue
    next({path: '/index'});
   }else{
    next();
   }
  }else{
   // 如果沒(méi)有session ,訪(fǎng)問(wèn)任何頁(yè)面。都會(huì)進(jìn)入到 登錄頁(yè)
   if (to.path === '/') { // 如果是登錄頁(yè)面的話(huà)，直接next() -->解決注銷(xiāo)后的循環(huán)執(zhí)行bug
    next();
   } else { // 否則 跳轉(zhuǎn)到登錄頁(yè)面
    next({ path: '/' });
   }
  }
})

  loginOut(){
  // 注銷(xiāo)后 清除session信息 ，并返回登錄頁(yè)
  window.sessionStorage.removeItem('data');
  this.common.startHacking(this, 'success', '注銷(xiāo)成功！');
  this.$router.push('/index'); 
  }