router.beforeEach(async (to, from, next) => {
 const { name, meta } = to;
 const { requireLogin } = meta;
 if (name === 'login') { // 如果是登录页则用next方法resolve掉这个钩子，如果不是，进行到下一个判断
  return next();  
 }
 const needLogin = requireLogin && !store.getters.user.isLogin; // 从store中读取是否获取了已登录的信息
 if (needLogin) {
  return next({  // 如果没有则跳转到登录页，将当前路由路径放到参数中
   name: 'login',
   params: { back: to },
  });
 }
 return next(); 
});

 loginSuccess() {
   const { params: { back } } = this.$route;
   const route = back || { name: 'home' };
   const { name, params, query } = route;
   this.$router.replace({ name, params, query });
  },