//红色部分为增改地方！！！
 1 import Vue from 'vue'
 2 import VueRouter from 'vue-router'
 3 import parent from './transition.vue'
 4 Vue.use(VueRouter)
 5 
 6 const Home={template:`<div>Home内容 - {{$route.query.a}}</div>`}
 7 // const parent={template:`<div>parent内容</div>`}
 8 const page404={template:`
 9     <div><h2>error:404</h2></div>`,
10     beforeRouteEnter:(to,from,next) => {
11         console.log(to)
12         console.log(from)
13         // next(false)
14         next()
15     },
16     beforeRouteLeave:(to,from,next) => {
17         console.log(to)
18         console.log(from)
19         // next(false)
20         next()
21     }
22 }
23 
24 const router=new VueRouter({
25     mode:'history',
26     base:__dirname,
27     routes:[
28         {path:'/',component:Home},
29         {path:'/parent',component:parent,
30             beforeEnter:(to,from,next) => {
31                 console.log(to)
32                 console.log(from)
33                 // next(false)
34                 next({path:'/'})
35             }
36     },
37         {path:'*',component:page404}
38     ]
39 })
40 
41 new Vue({
42     router,
43     data(){
44         return{
45             aaa:'fade'
46         }
47     },
48     template:`
49         <div>
50             <p>hello</p>
51             <button v-on:click="houtui">后退</button>
52             <button v-on:click="qianjin">前进</button>
53             <button v-on:click="home">首页</button>
54             <button v-on:click="query">query</button>
55             <ul>
56                 <li><router-link to="/">/</router-link></li>
57                 <li><router-link to="/parent">parent</router-link></li>
58                 <li><router-link to="/qqqqqqqqqqqqqqqqqqqqq">Where not here</router-link></li>
59             </ul>
60             <transition :name="aaa" mode="out-in">
61                 <router-view></router-view>
62             </transition>
63         </div>
64     `,
65     watch:{
66         '$route'(to,from){
67             if(from.path=='/parent'){
68                 this.aaa='fade1'
69             }else{
70                 this.aaa='fade2'
71             }
72         }
73     },
74     methods:{
75         houtui:function(){
76             router.go(-1)
77         },
78         qianjin:function(){
79             router.go(1)
80         },
81         home:function(){
82             router.push('/')
83         },
84         query:function(){
85             router.push({path:'/',query:{a:1,b:2}})
86         }
87     }
88 }).$mount("#app")