本篇导航：
一、介绍与安装
vue是一套构建用户界面的JAVASCRIPT框架。与其它大型框架不同的是，Vue 被设计为可以自底向上逐层应用。Vue 的核心库只关注视图层，不仅易于上手，还便于与第三方库或既有项目整合。
1、安装
下载vue.js：https://cn.vuejs.org/v2/guide/installation.html
2、CDN
也可以不下载直接使用cdn
https://cdn.jsdelivr.net/npm/vue
3、引用
<script src="vue.js"></script>
<script src="https://cdn.jsdelivr.net/npm/vue"></script>
4、使用格式
{{}}，里面可以放表达式
<div id="app">
//和django中模版渲染一样使用｛｛变量｝｝插入文本
{{ message }}
</div> <script>
//实例化Vue
var app = new Vue({
//定位标签 表示在当前这个元素内开始使用VUE
el: '#app',
//变量
data: {
message: 'Hello Vue!'
}
})
<script>
二、vue常用指令
指令：是带有V-前缀的特殊属性，通过属性来操作元素
1、v-text,v-html
v-text：可以在元素当中插入值
v-html：元素不中不仅可以插入文本，还可以插入标签
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
</head>
<body>
<div id="app">
<p>{{msg}}</p>
<p>{{80+2}}</p>
<p>{{20>30}}</p>
我是：<h1 v-text="msg">{{str}}</h1>
你是：<h1 v-text="msg">2222222222222</h1> <h2 v-html="hd"></h2>
<h2 v-html="str"></h2>
</div>
<script>
new Vue({
el: "#app", //表示在当前这个元素内开始使用VUE
data:{
msg: "我是老大",
hd: "<input type='button' value='你是小三'>",
str: "我要发财!"
}
})
</script>
</body>
</html>
v-text,v-html
2、v-if,v-show
v-if：根据表达式的真假值来动态插入和移除元素
v-show：根据表达式的真假值来隐藏和显示元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
</head>
<body>
<div id="app">
<p v-if="pick">我是刘德华</p>
<p v-else>我是张学友</p>
<p v-show="temp">我是赵本山</p> <p v-show="ok">你喜欢我吗？</p> </div>
<script>
var vm = new Vue({
el: "#app",
data:{
pick: false,
temp: true,
ok: true
}
}) window.setInterval(function(){
vm.ok = !vm.ok;
},1000)
</script>
</body>
</html>
v-if,v-html
3、v-for
v-for：根据变量的值来循环渲染元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
}
</style>
</head>
<body>
<div id="app">
<ul>
<li v-for="(item,index2) in arr">
{{item}}: {{index2}}
</li>
</ul> <ul>
<li v-for="(item,key,index) in obj">
{{item}}: {{key}}:{{index}}
</li>
</ul>
<ul>
<li v-for="item in obj2">
{{item.username}}
{{item.age}}
{{item.sex}}
</li>
</ul>
<div v-for="i in 8">
{{i}}
</div>
</div>
<script>
new Vue({
el: "#app",
data:{
arr: [11,22,3344,55],
obj: {a:"张三",b:"李四",c:"王大拿",d:"谢大脚"},
obj2:[
{username: "jason"},
{age: 20},
{sex: "male"}
],
}
})
</script>
</body>
</html>
v-for
4、v-on
1）v-on：监听元素事件，并执行相应的操作
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
</head>
<body>
<div id="app">
<ul>
<li v-for="(item,index) in arr">
{{item}}: {{index}}
</li>
</ul> <input type="button" value="点我吧!" @click="show()"> </div>
<script>
new Vue({
el: "#app",
data:{
arr: [11,22,33,44,55],
],
},
//监听的事件
methods: {
show: function () {
this.arr.pop();
}
}
})
</script>
</body>
</html>
v-on
2）小实例：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
}
</style>
</head>
<body>
<div id="app">
<ul>
<li><input type="checkbox">苹果</li>
<li><input type="checkbox">香蕉</li>
<li><input type="checkbox">香梨</li>
<li><input type="checkbox" v-on:click="create()">其它</li>
<li v-html="htmlstr" v-show="test"></li>
</ul> </div>
<script>
var vm = new Vue({
el: "#app",
data:{
test: false,
htmlstr: "<textarea></textarea>"
},
methods: {
create: function () {
this.test = !this.test;
}
}
})
</script>
</body>
</html>
动态生成html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
display: inline-block;
border: 1px solid cornflowerblue;
height:40px;
line-height: 40px;
width: 120px;
text-align: center;
}
</style>
</head>
<body>
<div id="mybox">
<ul>
<li>
<span v-on:click="qh(true)">二唯码登录</span>
</li>
<li>
<span v-on:click="qh(false)">邮箱登录</span>
</li>
</ul> <div v-show="temp">
<img src="erma.jpg">
</div>
<div v-show="!temp">
<form action="http://mail.163.com" method="post">
<p><input type="email"></p>
<p><input type="password"></p>
<p><input type="submit" value="登录"></p>
</form>
</div>
</div>
<script>
new Vue({
el: "#mybox",
data: {
temp: true
},
methods: {
qh: function (t) {
this.temp = t
}
}
})
</script>
</body>
</html>
tag切换
3）v-on简写
//标准书写：
<input type="button" value="点我吧!" v-on:click="show()">
//简写：
<input type="button" value="点我吧!" @click="show()">
5、v-bind
1）v-bind：绑定元素的属性来执行相应的操作
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
.bk_1{
background-color: cornflowerblue;
width: 200px;
height: 200px;
}
.bk_2{
background-color: red;
width: 200px;
height: 200px;
}
.bk_3{
border: 5px solid #000;
}
</style>
</head>
<body>
<div id="app">
<a href="http://www.qq.com" v-bind:title="msg">腾讯</a>
<div :class="bk"></div>
<div :class="bk2"></div> <div :class="{bk_2:temp}">fdjjdjdkdkkeedd</div>
<div :class="[bk2,bk3]">8888888888</div>
</div>
<script>
var vm = new Vue({
el: "#app", //表示在当前这个元素内开始使用VUE
data:{
msg: "我想去腾讯公司上班",
bk:"bk_1",
bk2:"bk_2",
bk3:"bk_3",
temp: false
}
})
</script>
</body>
</html>
v-bind
2）简写
//标准写法：
<div v-bind:class="bk"></div>
//简写：
<div :class="bk"></div>
6、v-model
1）v-model：实现了数据和视图的双向绑定
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
}
</style>
</head>
<body>
<div id="app">
<input v-model="msg">
<p>{{msg}}</p>
<input type="button" value="变化" @click="change">
</div>
<script>
new Vue({
el: "#app",
data:{
msg: "aaaaa"
},
methods: {
change: function () {
this.msg = 8888888;
}
} })
</script>
</body>
</html>
v-model
2）简单实现学生信息增删改：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
}
.tds{
height: 15px;
width: 175px;
}
</style>
</head>
<body>
<div id="app">
<div>
<input type="text" placeholder="姓名" v-model="username">
<input type="text" placeholder="年龄" v-model="age">
<input type="button" value="增加" @click="add">
</div>
<div>
<table cellpadding="0" border="1">
<tr v-for="(item,index) in arr">
<td :class="td" v-if="arr[index].temp">{{item.username}}</td>
<td :class="td" v-else><input v-model="msg_user"></td>
<td :class="td" v-if="arr[index].temp">{{item.age}}</td>
<td :class="td" v-else><input v-model="msg_age"></td> <td>
<input type="button" value="删除" @click="del(index)">
<input type="button" value="修改" @click="edit1(index)" v-show="arr[index].temp">
<input type="button" value="确定" @click="edit2(index)" v-show="!arr[index].temp">
</td>
</tr>
</table>
</div>
</div>
<script>
new Vue({
el: "#app",
data:{
temp:true,
td:"tds",
username: "",
age: "",
arr: [],
msg_user:"",
msg_age:""
},
methods: {
add: function () {
this.arr.push({username:this.username, age:this.age, temp:this.temp});
},
del: function (index) {
this.arr.splice(index,1);
},
edit1:function (index) {
this.arr[index].temp = !this.arr[index].temp;
this.msg_user = this.arr[index].username;
this.msg_age = this.arr[index].age
},
edit2:function (index) {
this.arr[index].temp = !this.arr[index].temp;
this.arr[index].username = this.msg_user;
this.arr[index].age = this.msg_age
}
}
})
</script>
</body>
</html>
当前行修改方式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
}
.tipbox{
width: 200px;
height:200px;
border: 1px solid cornflowerblue;
position: absolute;
background-color: #aaaaaa;
top: 200px;
left: 600px;
}
</style>
</head>
<body>
<div id="app">
<div>
<input type="text" placeholder="姓名" v-model="username">
<input type="text" placeholder="年龄" v-model="age">
<input type="button" value="增加" @click="add">
</div>
<div>
<table cellpadding="0" border="1">
<tr v-for="(item,index) in arr">
<td>{{item.username}}</td>
<td>{{item.age}}</td>
<td>{{index}}</td>
<td><input type="button" value="删除" @click="del(index)"></td>
<td><input type="button" value="修改" @click="showBox(index)"></td>
</tr>
</table>
</div>
<div class="tipbox" v-show="isShow">
<p><input type="text" placeholder="姓名" v-model="m_username"></p>
<p><input type="text" placeholder="年龄" v-model="m_age"></p>
<p>
<input type="button" value="确定" @click="save()">
<input type="button" value="取消" @click="cancel()">
</p>
</div>
</div>
<script>
new Vue({
el: "#app", //表示在当前这个元素内开始使用VUE
data:{
username: "",
age: "",
arr: [],
isShow:false,
m_username: "",
m_age: "",
n: 0
},
methods: {
add: function () {
this.arr.push({username:this.username, age: this.age});
},
del: function (index) {
this.arr.splice(index,1);
},
showBox: function (index) {
this.isShow = true;
this.n = index;
this.m_username = this.arr[index].username;
this.m_age = this.arr[index].age;
},
cancel: function () {
this.isShow = false
},
save: function () {
this.arr[this.n].username = this.m_username;
this.arr[this.n].age = this.m_age;
this.isShow = false
}
}
})
</script>
</body>
</html>
类模态框修改方式
7、自定义指令
特定指令无法满足我们的开发需求时可以自定义指令
当进入一个页面时，输入框获取焦点，且背景颜色是蓝色，字体颜色是白色：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
<style>
ul li{
list-style: none;
}
</style>
</head>
<body>
<div id="app">
<input type="text" v-focus>
</div>
<script>
new Vue({
el: "#app", //表示在当前这个元素内开始使用VUE
data:{ },
//自定义指令
directives: {
focus: { //指令的名字
//当绑定的元素显示时
inserted: function (tt) {
tt.focus();
tt.style.backgroundColor = "blue";
tt.style.color = "#fff"
}
}
}
})
</script>
</body>
</html>
自定义指令
8、computed计算属性
从前面的代码中可以了解{{}}中可以放表达式 但是当简单的表达式无法满足业务时就需要计算属性了
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="vue.js"></script>
</head>
<body>
<div id="app">
<p>{{msg}}</p>
</div>
<script>
var vm = new Vue({
el: "#app",
data: {
temp: 1001
},
//计算属性
computed: {
msg: function () {
if(this.temp > 1000){
return parseInt(this.temp/10)-1
} else {
return this.temp-1
}
}
}
})
</script>
</body>
</html>