vue如何修改浏览器的标题title

Vue.directive('title', {
  inserted: function (el, binding) {
    document.title = el.dataset.title
  }
})

v-title data-title="我的"

<template>
    <header class="header_home user_reg" v-title data-title=""> 
   <div class="top_box hidden-xs"> 
    <div class="container"> 
      <router-link to="/" class="logo"> 
        <img src="../../../assets/image/5b10f166c3332.png" alt="" /> 
      </router-link> 
     <ul class="navs">
        <li>
            <router-link to="/regist">注册</router-link>
        </li> 
        <li>
          <router-link to="/login">登录</router-link>
        </li> 
        <li>
          <router-link to="/CooperUser">合作平台</router-link>
        </li> 
     </ul> 
    </div> 
   </div> 
  </header>
</template>

{
            path: '/login',
            name: 'login',
            component(resolve) {
                require(['./views/login.vue'], resolve)
            },
            meta: {
                title: '登录页',
                keepAlive: true, // 需要被缓存
            }
        },
        {
            path: '/regist',
            name: 'regist',
            component(resolve) {
                require(['./views/regist.vue'], resolve)
            },
            meta: {
                title: '注册页',
                keepAlive: true, // 需要被缓存
            }
        },
        {
            path: '/newList',
            name: 'newlist',
            component(resolve) {
                require(['./views/newsList.vue'], resolve)
            },
            meta: {
                title: '新闻列表',
                keepAlive: true, // 需要被缓存
            }
        }

router.beforeEach((to, from, next) => {
    window.document.title = to.meta.title == undefined?'默认标题':to.meta.title
    if (to.meta.requireAuth) {
        let token = Cookies.get('access_token');
        let anonymous = Cookies.get('user_name');
        if (token) { 
            
                next({
                    path: '/login',
                    query: {
                        redirect: to.fullPath
                    } 
                })
          
        }
    }
    next();
})

import VueWechatTitle from 'vue-wechat-title'
Vue.use(VueWechatTitle)

routes: [{
            path: '/',
            name: 'index',
            component: Index,
            meta: {
                title: "漫岛-一个有趣的网站"
            }
        },
        {
            path: '/recruit',
            name: 'recruit',
            component: Recruit,
            meta: {
                title: "漫岛-团队伙伴招募"
            }
        }
    ]

<!-- 任意元素中加 v-wechat-title 指令 建议将标题放在 route 对应meta对象的定义中 -->
<div v-wechat-title="$route.meta.title"></div>
<!--或者-->
<router-view v-wechat-title="$route.meta.title"></router-view>