import Vue from 'vue'
import VueRouter from 'vue-router'
 
import Home from '../components/home/home.vue'

Vue.use(VueRouter);
const router = new VueRouter({
 mode : 'history',
 base: __dirname,
  routes: [
  {
    path: historyUrl + '/',
    component: Home,
    name : '主页'
  },
]}

import router from './main/router.js'
const app = new Vue({
 router : router,
 watch : {
  '$route' (to,from,next){
   //console.log(to) //路由监听
   //console.log(from)
  }
  },
 render : h => h(App)
}).$mount('#app');

<template>
 <div ref="index"> //ref标识
   <Title :refDome='refDome'></Title>
 </div>
</template>

<template>
 <div ref="index">
   <Title :refDome='refDome'></Title> //这里把data的值转给子组件Title 
 </div>
</template>
<script>
import Title from '../components/title'
export default {
  components:{
    Title
  },
  data(){
    return{
      refDome:null
    }
  },
  mounted(){
    this.refDome = this.$refs.index //在这里给data赋值，记得要在mounted赋值
  }
}

<script>
export default {
 props: ['refDome'],
}
</script>

// 点击切换全屏
  handleFullScreen() {
   if (this.screen % 2 == 0) {
    this.refDome.style.position = 'static'
    this.screen++
   } else {
    this.refDome.style.width = '100%'
    this.refDome.style.height = '100%'
    this.refDome.style.position = 'absolute'
    this.refDome.style.top = '0'
    this.refDome.style.left = '0'
    this.refDome.style.zIndex = '10'
    this.refDome.style.background = '#fff'
    this.screen++
   }
  },