时间:2020-10-04 14:43:40 | 栏目:Python代码 | 点击:次
vue常用内置指令
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>12_指令_内置指令</title> <style> [v-cloak] { display: none } </style> </head> <body> <!-- 常用内置指令 v:text : 更新元素的 textContent v-html : 更新元素的 innerHTML v-if : 如果为true, 当前标签才会输出到页面 v-else: 如果为false, 当前标签才会输出到页面 v-show : 通过控制display样式来控制显示/隐藏 v-for : 遍历数组/对象 v-on : 绑定事件监听, 一般简写为@ v-bind : 强制绑定解析表达式, 可以省略v-bind v-model : 双向数据绑定 ref : 为某个元素注册一个唯一标识, vue对象通过$refs属性访问这个元素对象 v-cloak : 使用它防止闪现表达式, 与css配合: [v-cloak] { display: none } --> <div id="example"> <p v-cloak>{{content}}</p> <p v-text="content"></p> <!--p.textContent = content--> <p v-html="content"></p> <!--p.innerHTML = content--> <p ref="msg">abcd</p> <button @click="hint">提示</button> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#example', data: { content: '<a href="http://www.baidu.com" rel="external nofollow" rel="external nofollow" >百度一下</a>' }, methods: { hint () { alert(this.$refs.msg.innerHTML) } } }) </script> </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script> </head> <body> <div id="app"> <!-- 数据绑定 --> <a v-bind:href="url" rel="external nofollow" >百度一下</a> <!-- 双向数据绑定 --> <input type="text" v-model="name"> <p>{{name}}</p> <!-- 绑定回车键 --> <input type="text" @keyup.enter="showEnt"> <!-- 点击事件 --> <button @click="show('888')">按钮</button> <!-- 获取数组值 --> <p>{{arr[1]}}</p> <!-- 获取对象属性 --> <p>{{users[1].name}}</p> </div> <script> var app = new Vue({ el: "#app", data: { name:'', url: 'http://www.baidu.com', arr: ["a", "b", "c", "d"], users: [ { name: "aowei", age: 12 }, { name: "baozi", age: 13 }, { name: "bbbbb", age: 14 }, ] }, methods: { // 绑定回车键 showEnt: function () { alert("666"); }, // 传参 show: function (num) { alert(num); } }, } ) </script> </body> </html>
计算属性和监视
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>03_计算属性和监视</title> </head> <body> <!-- 1. 计算属性 在computed属性对象中定义计算属性的方法 在页面中使用{{方法名}}来显示计算的结果 2. 监视属性: 通过通过vm对象的$watch()或watch配置来监视指定的属性 当属性变化时, 回调函数自动调用, 在函数内部进行计算 3. 计算属性高级: 通过getter/setter实现对属性数据的显示和监视 计算属性存在缓存, 多次读取只执行一次getter计算 --> <div id="demo"> 姓: <input type="text" placeholder="First Name" v-model="firstName"><br> 名: <input type="text" placeholder="Last Name" v-model="lastName"><br> <!--fullName1是根据fistName和lastName计算产生--> 姓名1(单向): <input type="text" placeholder="Full Name1" v-model="fullName1"><br> 姓名2(单向): <input type="text" placeholder="Full Name2" v-model="fullName2"><br> 姓名3(双向): <input type="text" placeholder="Full Name3" v-model="fullName3"><br> <p>{{fullName1}}</p> <p>{{fullName1}}</p> </div> <script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script> <script type="text/javascript"> const vm = new Vue({ el: '#demo', data: { firstName: 'A', lastName: 'B', fullName2: 'A-B' }, // 计算属性配置: 值为对象 computed: { fullName1:function() { // 属性的get() return this.firstName + '-' + this.lastName; }, fullName3: { // 当获取当前属性值时自动调用, 将返回值(根据相关的其它属性数据)作为属性值 get () { return this.firstName + '-' + this.lastName }, // 当属性值发生了改变时自动调用, 监视当前属性值变化, 同步更新相关的其它属性值 set (value) {// fullName3的最新value值 A-B23 // 更新firstName和lastName const names = value.split('-') this.firstName = names[0] this.lastName = names[1] } } }, watch: { // 配置监视firstName firstName: function (value) { // 相当于属性的set // 更新fullName2 this.fullName2 = value + '-' + this.lastName } } }) // 监视lastName vm.$watch('lastName', function (value) { // 更新fullName2 this.fullName2 = this.firstName + '-' + value }) </script> </body> </html>
列表渲染
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script> </head> <body> <div id="app"> <ul> <li v-for='item in arr'> {{item}} </li> </ul> <ul> <li v-for="(item,index) in arr"> {{index}} --- {{item}} </li> </ul> <h3 v-for="user in users" v-bind:title="user.name"> {{user.name}} --- {{user.age}} </h3> <button @click="add">add按钮</button> <button @click="del">del按钮</button> </div> <script> var app = new Vue({ el: "#app", data: { arr: ["a", "b", "c", "d"], users: [ { name: "aowei", age: 12 }, { name: "baozi", age: 13 }, { name: "bbbbb", age: 14 }, ] }, methods: { add: function () { console.log("add"); this.users.push({ name: "hello", age: "3" }); }, del: function () { console.log("del"); this.users.shift(); } }, } ) </script> </body> </html>
class & style 绑定
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>04_class与style绑定</title> <style> .classA { color: red; } .classB { background: blue; } .classC { font-size: 20px; } </style> </head> <body> <!-- 1. 理解 在应用界面中, 某个(些)元素的样式是变化的 class/style绑定就是专门用来实现动态样式效果的技术 2. class绑定: :class='xxx' xxx是字符串 xxx是对象 xxx是数组 3. style绑定 :style="{ color: activeColor, fontSize: fontSize + 'px' }" 其中activeColor/fontSize是data属性 --> <div id="demo"> <h2>1. class绑定: :class='xxx'</h2> <p :class="myClass">xxx是字符串</p> <p :class="{classA: hasClassA, classB: hasClassB}">xxx是对象</p> <p :class="['classA', 'classB']">xxx是数组</p> <h2>2. style绑定</h2> <p :style="{color:activeColor, fontSize}">:style="{ color: activeColor, fontSize: fontSize + 'px' }"</p> <button @click="update">更新</button> </div> <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#demo', data: { myClass: 'classA', hasClassA: true, hasClassB: false, activeColor: 'red', fontSize: '20px' }, methods: { update () { this.myClass = 'classB' this.hasClassA = !this.hasClassA this.hasClassB = !this.hasClassB this.activeColor = 'yellow' this.fontSize = '30px' } } }) </script> </body> </html>
条件渲染
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>08_条件渲染</title> </head> <body> <!-- 1. 条件渲染指令 v-if v-else v-show 2. 比较v-if与v-show 如果需要频繁切换 v-show 较好 --> <div id="demo"> <p v-if="ok">表白成功</p> <p v-else>表白失败</p> <hr> <p v-show="ok">求婚成功</p> <p v-show="!ok">求婚失败</p> <button @click="ok=!ok">切换</button> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#demo', data: { ok: true, } }) </script> </body> </html>
事件处理
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>07_事件处理</title> </head> <body> <!-- 1. 绑定监听: v-on:xxx="fun" @xxx="fun" @xxx="fun(参数)" 默认事件形参: event 隐含属性对象: $event 2. 事件修饰符: .prevent : 阻止事件的默认行为 event.preventDefault() .stop : 停止事件冒泡 event.stopPropagation() 3. 按键修饰符 .keycode : 操作的是某个keycode值的健 .enter : 操作的是enter键 --> <div id="example"> <h2>1. 绑定监听</h2> <button @click="test1">test1</button> <button @click="test2('abc')">test2</button> <button @click="test3('abcd', $event)">test3</button> <h2>2. 事件修饰符</h2> <!-- 阻止事件默认行为 --> <a href="http://www.baidu.com" rel="external nofollow" rel="external nofollow" @click.prevent="test4">百度一下</a> <div style="width: 200px;height: 200px;background: red" @click="test5"> <div style="width: 100px;height: 100px;background: blue" @click.stop="test6"></div> <!-- 阻止事件冒泡 --> </div> <h2>3. 按键修饰符</h2> <!-- enter键/13 --> <input type="text" @keyup.13="test7"> <input type="text" @keyup.enter="test7"> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#example', data: { }, methods: { test1(event) { alert(event.target.innerHTML) }, test2 (msg) { alert(msg) }, test3 (msg, event) { alert(msg+'---'+event.target.textContent) }, test4 () { alert('点击了链接') }, test5 () { alert('out') }, test6 () { alert('inner') }, test7 (event) { console.log(event.keyCode) alert(event.target.value) } } }) </script> </body> </html>
表单数据绑定
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>08_表单输入绑定</title> </head> <body> <!-- 1. 使用v-model(双向数据绑定)自动收集数据 text/textarea checkbox radio select --> <div id="demo"> <!-- 阻止表单自动提交,手动ajax提交 --> <form action="/xxx" @submit.prevent="handleSubmit"> <span>用户名: </span> <input type="text" v-model="username"><br> <span>密码: </span> <input type="password" v-model="pwd"><br> <span>性别: </span> <input type="radio" id="female" value="女" v-model="sex"> <label for="female">女</label> <input type="radio" id="male" value="男" v-model="sex"> <label for="male">男</label><br> <span>爱好: </span> <input type="checkbox" id="basket" value="basket" v-model="likes"> <label for="basket">篮球</label> <input type="checkbox" id="foot" value="foot" v-model="likes"> <label for="foot">足球</label> <input type="checkbox" id="pingpang" value="pingpang" v-model="likes"> <label for="pingpang">乒乓</label><br> <span>城市: </span> <select v-model="cityId"> <option value="">未选择</option> <option :value="city.id" v-for="(city, index) in allCitys" :key="city.id">{{city.name}}</option> </select><br> <span>介绍: </span> <textarea rows="10" v-model="info"></textarea><br><br> <input type="submit" value="注册"> </form> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#demo', data: { username: '', pwd: '', sex: '男', likes: ['foot'], allCitys: [{id: 1, name: 'BJ'}, {id: 2, name: 'SS'}, {id: 3, name: 'SZ'}], cityId: '2', info: '' }, methods: { handleSubmit () { console.log(this.username, this.pwd, this.sex, this.likes, this.cityId, this.info) alert('提交注册的ajax请求') } } }) </script> </body> </html>
生命周期
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>09_Vue实例_生命周期</title> </head> <body> <!-- 1. vue对象的生命周期 1). 初始化显示 * beforeCreate() * created() * beforeMount() * mounted() 2). 更新状态 * beforeUpdate() * updated() 3). 销毁vue实例: vm.$destory() * beforeDestory() * destoryed() 2. 常用的生命周期方法 created()/mounted(): 发送ajax请求, 启动定时器等异步任务 beforeDestory(): 做收尾工作, 如: 清除定时器 --> <div id="test"> <button @click="destroyVue">destory vue</button> <p v-if="isShow">尚硅谷IT教育</p> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#test', data: { isShow: true }, beforeCreate() { console.log('beforeCreate()') }, created() { console.log('created()') }, beforeMount() { console.log('beforeMount()') }, mounted () { console.log('mounted()') // 执行异步任务 this.intervalId = setInterval(() => { console.log('-----') this.isShow = !this.isShow }, 1000) }, beforeUpdate() { console.log('beforeUpdate()') }, updated () { console.log('updated()') }, beforeDestroy() { console.log('beforeDestroy()') // 执行收尾的工作 clearInterval(this.intervalId) }, destroyed() { console.log('destroyed()') }, methods: { destroyVue () { this.$destroy() } } }) </script> </body> </html>
过渡,动画
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>10_过渡&动画1</title> <style> /*指定过渡样式*/ .xxx-enter-active, .xxx-leave-active { transition: opacity 1s } /*指定隐藏时的样式*/ .xxx-enter, .xxx-leave-to { opacity: 0; } .move-enter-active { transition: all 1s } .move-leave-active { transition: all 3s } .move-enter, .move-leave-to { opacity: 0; transform: translateX(20px) } </style> </head> <body> <!-- 1. vue动画的理解 操作css的trasition或animation vue会给目标元素添加/移除特定的class 2. 基本过渡动画的编码 1). 在目标元素外包裹<transition name="xxx"> 2). 定义class样式 1>. 指定过渡样式: transition 2>. 指定隐藏时的样式: opacity/其它 3. 过渡的类名 xxx-enter-active: 指定显示的transition xxx-leave-active: 指定隐藏的transition xxx-enter: 指定隐藏时的样式 --> <div id="demo"> <button @click="show = !show">Toggle</button> <transition name="xxx"> <p v-show="show">hello</p> </transition> </div> <hr> <div id="demo2"> <button @click="show = !show">Toggle2</button> <transition name="move"> <p v-show="show">hello</p> </transition> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> new Vue({ el: '#demo', data: { show: true } }) new Vue({ el: '#demo2', data: { show: true } }) </script> </body> </html>
过滤器
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>11_过滤器</title> </head> <body> <!-- 1. 理解过滤器 功能: 对要显示的数据进行特定格式化后再显示 注意: 并没有改变原本的数据, 可是产生新的对应的数据 2. 编码 1). 定义过滤器 Vue.filter(filterName, function(value[,arg1,arg2,...]){ // 进行一定的数据处理 return newValue }) 2). 使用过滤器 <div>{{myData | filterName}}</div> <div>{{myData | filterName(arg)}}</div> --> <!--需求: 对当前时间进行指定格式显示--> <div id="test"> <h2>显示格式化的日期时间</h2> <p>{{time}}</p> <p>最完整的: {{time | dateString}}</p> <p>年月日: {{time | dateString('YYYY-MM-DD')}}</p> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript" src="https://cdn.bootcss.com/moment.js/2.22.1/moment.js"></script> <script> // 定义过滤器 Vue.filter('dateString', function (value, format='YYYY-MM-DD HH:mm:ss') { return moment(value).format(format); }) new Vue({ el: '#test', data: { time: new Date() }, mounted () { setInterval(() => { this.time = new Date() }, 1000) } }) </script> </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>12_指令_自定义指令</title> </head> <body> <!-- 1. 注册全局指令 Vue.directive('my-directive', function(el, binding){ el.innerHTML = binding.value.toupperCase() }) 2. 注册局部指令 directives : { 'my-directive' : { bind (el, binding) { el.innerHTML = binding.value.toupperCase() } } } 3. 使用指令 v-my-directive='xxx' --> <!-- 需求: 自定义2个指令 1. 功能类型于v-text, 但转换为全大写 2. 功能类型于v-text, 但转换为全小写 --> <div id="test"> <p v-upper-text="msg"></p> <p v-lower-text="msg"></p> </div> <div id="test2"> <p v-upper-text="msg"></p> <p v-lower-text="msg"></p> </div> <script type="text/javascript" src="../js/vue.js"></script> <script type="text/javascript"> // 注册一个全局指令 // el: 指令所在的标签对象 // binding: 包含指令相关数据的容器对象 Vue.directive('upper-text', function (el, binding) { console.log(el, binding) el.textContent = binding.value.toUpperCase() }) new Vue({ el: '#test', data: { msg: "I Like You" }, // 注册局部指令 directives: { 'lower-text'(el, binding) { console.log(el, binding) el.textContent = binding.value.toLowerCase() } } }) new Vue({ el: '#test2', data: { msg: "I Like You Too" } }) </script> </body> </html>
本文主要介绍了vue常用指令代码实例,更多关于vue常用指令请查看下面的相关链接