vue---day03
1. Vue的生命周期
- 创建和销毁的时候可以做一些我们自己的事情
- beforeCreated
- created
- beforeMount
- mounted
- beforeUpdate
- updated
- activated
- deactivated
- beforeDestroy
- destroyed
1.1 知识点回顾
1.1.1 beforeCreated 在实例创建之前除标签外,所有的vue实例需要的数据,事件都不存在
1.1.2 created 实例被我创建之后,data和事件已经被解析到,el还没有解析到
1.1.3 beforeMount 开始找标签,数据还没被渲染,事件也没被监听
1.1.4 mounted 开始渲染数据和监听事件
1.1.5 beforeUpdate 数据已经被修改在虚拟DOM,但是还没渲染到页面上
1.1.6 updated 开始使用Diff算法,将虚拟DOM中的要修改数据应用到页面上,真实DOM中的数据也被修改了
1.1.7 beforeDestroy 所有的数据都存在
1.1.8 destroyed 所有的数据都存在(在虚拟DOM中)
1.1.9 <keep-alive></keep-alive> Vue提供的用来缓存消除的标签
- activated和deactivated取代了beforeDestroy和destroyed的执行
2. Vue的路由系统
2.1 VueRouter的实现原理
- 通过监听a的锚点值,来动态的显示页面内容
2.2 VueRouter的安装使用
2.2.1 第一步:
1 Vue.use(VueRouter)
2.2.2 第二步:创建router对象和每个url对应的组件
1 let Home = { 2 template:``, 3 }; 4 5 let Login = { 6 template:``, 7 }; 8 9 let router = new VueRouter({ 10 routes:[ 11 { 12 name:'home', 13 path:'/', 14 components:Home', 15 }, 16 { 17 name:'login', 18 path:'/login', 19 components:Login, 20 }, 21 ] 22 });
2.2.3 第三步:注册router对象到根实例中
1 new Vue({ 2 el:'#app', 3 template:`<App/>`, 4 components:{ 5 App, 6 } 7 router:router, 8 });
2.2.4 第四步:
1 let App = { 2 template:` 3 <router-link :to='{ name: 'home' }'>首页</router-link> 4 <router-link :to='{ name: 'login' }'>登录</router-link> 5 6 <router-view></router-view> 7 ` 8 }
2.3 VueRouter之命名路由
同上
2.4 VueRouter之路由参数
- user_change/1/
- user_detail/?user_id=1
1 let Home = { 2 template:` 3 <h1>欢迎</h1> 4 ` 5 }; 6 7 let UserDetail = { 8 template:` 9 <h2>用户详情</h2> 10 `, 11 }; 12 13 let UserChange = { 14 template:` 15 <h3>修改用户信息</h3> 16 `, 17 }; 18 19 let App = { 20 template:` 21 <div> 22 <router-link :to="{ name: 'home' }">首页</router-link> 23 <router-link :to="{ name: 'user_detail', query: { user_id: 1 } }">用户详情</router-link> 24 <router-link :to="{ name: 'user_change', params: { user_id: 1 } }">修改用户信息</router-link> 25 <router-view></router-view> 26 </div> 27 ` 28 }; 29 30 let router = new VueRouter({ 31 routes:[ 32 { 33 'name':'home', 34 'path':'/', 35 'component':Home, 36 }, 37 { 38 'name':'user_detail', 39 'path':'/user_detail', 40 'component':UserDetail, 41 }, 42 { 43 'name':'user_change', 44 'path':'/user_change/:user_id', 45 'component':UserChange, 46 }, 47 ] 48 });
2.5 VueRouter之路由参数的实现原理
1 this.$router.params 2 this.$router.query
2.6 VueRouter之子路由
1 let Home = { 2 template: ` 3 <div> 4 <h1>欢迎</h1> 5 </div> 6 ` 7 }; 8 9 let Phone = { 10 template: ` 11 <div> 12 <h2>手机品牌</h2> 13 <router-link :to="{name: 'huawei'}" append>华为</router-link> 14 <router-link :to="{name: 'oneplus'}" append>一加</router-link> 15 16 <router-view></router-view> 17 </div> 18 `, 19 }; 20 let HuaWei = { 21 template: ` 22 <div> 23 <h3>华为手机</h3> 24 </div> 25 `, 26 }; 27 let OnePlus = { 28 template: ` 29 <div> 30 <h3>一加手机</h3> 31 </div> 32 `, 33 34 let App = { 35 template: ` 36 <div> 37 <router-link :to="{ name: 'home' }">首页</router-link> 38 <router-link :to="{ name: 'phone'}">手机品牌</router-link> 39 40 <router-view></router-view> 41 </div> 42 `, 43 }; 44 45 let router = new VueRouter({ 46 routes: [ 47 { 48 'name': 'home', 49 'path': '/', 50 'component': Home, 51 }, 52 { 53 'name': 'phone', 54 'path': '/phone', 55 'component': Phone, 56 'children': [ 57 { 58 'name':'huawei', 59 'path': 'huawei', 60 'component': HuaWei, 61 }, 62 { 63 'name':'oneplus', 64 'path': 'oneplus', 65 'component': OnePlus, 66 }, 67 ], 68 69 }, 70 ] 71 });
2.7 VueRouter之子路由重定向
1 let router = new VueRouter({ 2 routes: [ 3 { 4 name: 'home', 5 path: '/', 6 component: Home, 7 }, 8 { 9 name: 'login', 10 path: '/login', 11 component: Login 12 }, 13 { 14 name: 'pay', 15 path: '/pay', 16 redirect: '/login', 17 component: Pay, 18 }, 19 ] 20 });
2.8 VueRouter之子路由的钩子函数
1 let router = new VueRouter({ 2 routes: [ 3 { 4 name: 'home', 5 path: '/', 6 component: Home, 7 }, 8 { 9 name: 'login', 10 path: '/login', 11 component: Login 12 }, 13 { 14 name: 'pay', 15 path: '/pay', 16 meta: { required_login: true }, 17 component: Pay, 18 }, 19 ] 20 }); 21 22 // 通过router对象的beforeEach(function(to, from, next)) 23 router.beforeEach(function (to, from, next) { 24 console.log("to: ", to); 25 console.log("from: ", from); 26 console.log("next: ", next); 27 if ( to.meta.required_login ) { 28 next('/login'); 29 } else { 30 next(); 31 } 32 });
2.9 VueRouter之子路由的去 # 号
1 let router = new VueRouter({ 2 mode:'history', 3 routes: [ 4 { 5 name: 'home', 6 path: '/', 7 component: Home, 8 }, 9 { 10 name: 'login', 11 path: '/login', 12 component: Login 13 }, 14 { 15 name: 'pay', 16 path: '/pay', 17 component: Pay, 18 }, 19 ] 20 });