@TOC
- 推荐Vscode编译器、vue官网：https://cn.vuejs.org/v2/guide/installation.html
1.v-bind（style对象属性）
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<!-- <h2 :style="{key（属性值）:value(属性值)}">{{message}}</h2> -->
<h2 :style="{fontSize:finalSize,color:finalColor}">{{message}}</h2>
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
name: 'codewhy',
finalSize: '50px',
finalColor: 'red'
}
})
</script>
</body>
</html>函数方法改进：
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<!-- <h2 :style="{key（属性值）:value(属性值)}">{{message}}</h2> -->
<h2 :style="getStyles()">{{message}}</h2>
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
name: 'codewhy',
finalSize: '50px',
finalColor: 'red'
},
methods:{
getStyles:function(){
return {fontSize:this.finalSize,color:this.finalColor};
}
}
})
</script>
</body>
</html>2.v-bind（style数组属性）
了解即可
3.计算属性
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<h2>{{firstname}}{{lastname}}</h2>
<h2>{{getFullName()}}</h2>
<h2>{{fullName}}</h2>
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
firstname: 'a',
lastname: 'b',
},
methods:{
getFullName(){
return this.firstname + this.lastname;
}
},
//计算属性
computed: {
fullName:function(){
return this.firstname + this.lastname;
}
}
})
</script>
</body>
</html>4.计算属性的复杂操作
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<h2>总价:{{totalPrice}}</h2>
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
books: [
{id:110,name:'Unix',price:119},
{id:111,name:'代码大全',price:201},
{id:112,name:'深入理解计算机原理',price:52}
]
},
//有缓存，方法没有
computed: {
totalPrice:function(){
let result = 0;
for(let i =0;i<this.books.length;i++){
result += this.books[i].price;
}
return result;
}
}
})
</script>
</body>
</html>5.计算属性getter、setter
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
{{message}}
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
firstname: 'a',
lastname: 'b',
},
computed: {
// fullName:function(){
// return this.firstname + this.lastname;
// }
//属性fullName，一般只实现get方法，所以一般可以简写为上面的写法
fullName :{
set:function(newValue){
console.log(newValue);
const names = newValue.split(" ");
this.firstname = names[0];
this.lastname = names[1];
},
get:function(){
return this.firstname + this.lastname;
}
}
}
})
</script>
</body>
</html>6.计算属性computed和methods的对比
- 计算属性：一次计算，多次使用，有缓存
- methods：多次计算，多次使用，无缓存
7.es6语法
7.1 let/var
注：let有闭包，var没有，推荐使用let
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<button>按钮1</button>
<button>按钮2</button>
<button>按钮3</button>
<button>按钮4</button>
<button>按钮5</button>
<script src='../js/vue.js'></script>
<script>
//ES5之前因为 if、for没有块级作用域的概念，所以很多时候需要借鉴function的作用域
//1.变量作用域：变量在什么范围内是可用
{
var name = 'why';
console.log(name);
}
console.log(name);//var没有块级作用域
//2.没有块级作用域引起的问题 if
var func;
if(true){
var name = 'why';
func = function(){
console.log(name);
}
//func();
}
name = 'modify';
func();
//3.没有块级作用域引起的问题 for
//为什么闭包可以解决问题：函数是一个作用域
// var btns = document.getElementsByTagName('button')
// for(var i = 0;i<btns.length;i++){
// (function(i){ //0
// btns[i].addEventListener('click',function(){
// console.log('第' + i + '个按钮被点击');
// })
// })(i)
// }
// 4.es6
const btns = document.getElementsByTagName('button')
for(let i = 0;i<btns.length;i++){
btns[i].addEventListener('click',function(){
console.log('第' + i + '个按钮被点击');
})
}
</script>
</body>
</html>7.2 const
7.3 对象字面量增强
8.v-on
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<h2>{{counter}}</h2>
<!-- <button v-on:click="counter++">+</button>
<button v-on:click="counter--">-</button> -->
<button @click="add">+</button>
<button v-on:click="sub">-</button>
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
counter: 0
},
methods:{
add(){
this.counter++;
},
sub(){
this.counter--;
}
}
})
</script>
</body>
</html>语法糖：@click
9.v-on参数
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<!-- 不需要参数的时候，不需要括号 -->
<button @click="btn1Click">按钮1</button>
<button @click="btn1Click">按钮1</button>
<!-- 需要参数的时候，默认传入event参数，不需要括号 -->
<button @click="btn2Click">按钮2</button>
<button @click="btn2Click">按钮2</button>
<!-- 需要参数的时候，并且需要event参数，-->
<button @click="btn3Click(123,$event)">按钮3</button>
<button @click="btn3Click">按钮3</button>
<!-- 需要参数的时候，并且需要event参数，-->
<button @click="btn3Click(123,$event)">按钮3</button>
<button @click="btn3Click">按钮3</button>
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
name: 'codewhy'
},methods: {
btn1Click(){
console.log(123);
},
btn2Click(event){
console.log(event);
},
btn3Click(first,event){
console.log(first);
console.log(event);
}
}
})
</script>
</body>
</html>10.v-on修饰符
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div id='app'>
<!-- 1.stop修饰符的使用(停止冒泡) -->
<div @click="divClick">
<button @click.stop='btnClick'>
按钮
</button>
</div>
<br>
<!-- 2.prevent修饰符的使用(阻止默认行为) -->
<form action="baidu">
<input type="submit" value="提交" @click.prevent="submitClick">
</form>
<!-- 3.监听某个键盘的键帽 -->
<input type="text" @keyup.enter="keyUp">
</div>
<script src='../js/vue.js'></script>
<script>
const app = new Vue({
el:'#app', //用于挂载要管理的元素
data:{ //定义数据
message: '你好啊，李银河！',
name: 'codewhy'
},
methods: {
btnClick(){
console.log("btnClick");
},
divClick(){
console.log("divClick");
},
submitClick(){
console.log("submitClick");
},
keyUp(){
console.log("keyup");
}
}
})
</script>
</body>
</html>
