function setMetaTitle(title) {
 document.title = title
 let mobile = navigator.userAgent.toLowerCase()
 if (/iphone|ipad|ipod/.test(mobile)) {
  let iframe = document.createElement('iframe')
  iframe.style.display = 'none'
  // 替换成站标favicon路径或者任意存在的较小的图片即可
  iframe.setAttribute('src', 'static/img/blank.png')
  let iframeCallback = function () {
   setTimeout(function () {
    iframe.removeEventListener('load', iframeCallback)
    document.body.removeChild(iframe)
   }, 0)
  }
  iframe.addEventListener('load', iframeCallback)
  document.body.appendChild(iframe)
 }
}
 
 
export {
 setMetaTitle
}

import Vue from 'vue'
import VueRouter from 'vue-router'
import VueResource from 'vue-resource'
import routes from './router/router.js'
import filter from './utils/filter.js'
import { setMetaTitle } from './utils/util.js'
import App from './App.vue'
 
Vue.use(VueRouter)
Vue.use(VueResource)
 
Vue.directive('title', {
 inserted: function (el, binding) {
  setMetaTitle(binding.value)
 }
})
 
Object.keys(filter).forEach(function(k) {
 Vue.filter(k, filter[k]);
});
 
const router = new VueRouter({
 routes: routes
})
 
new Vue({
 router: router,
 render: h => h(App)
}).$mount('#app')

<h2 v-title="'页面标题'">通过指令设置页面标题</h2>