把子组件中的数据传递到父组件中
例：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>子给父传值</title>
</head>
<body>
<div class="itany">
<father></father>
</div>
<script src="./vue.js"></script>
<script>
Vue.component('father',{
template:`
<div>
<h1>{{num2}}</h1>
<child @meth='the'></child>
</div>
`,
data:function(){
return{
num2:''
}
},
methods:{
the:function(txt){
this.num2=txt
}
}
})
Vue.component('child',{
template:`
<button @click="show">传给父元素</button>
`,
data:function(){
return{
num:'我是子组件，我要传值给父组件'
}
},
methods:{
show:function(){
this.$emit('meth',this.num)
}
}
})
new Vue({
el:'.itany'
})
</script>
</body>
</html>
12041882-55005438ebec8c8b.png
注释：点击按钮时，就会弹出父组件传给子组件的数据
练习1：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>子给父传值练习</title>
</head>
<body>
<div class="itany">
<father></father>
</div>
<script src="vue.js"></script>
<script>
Vue.component('father',{
template:`
<div>
<h1>我是父元素</h1>
<p>请传值<b>{{mess}}</b></p>
<child @show="the"></child>
</div>
`,
data:function(){
return{
mess:""
}
},
methods:{
the:function(txt){
this.mess=txt
}
}
})
Vue.component('child',{
template:`
<div>
<h1>我是子元素</h1>
<input type="text" v-model="arr">
<button @click="add">传值</button>
</div>
`,
data:function(){
return{
arr:""
}
},
methods:{
add:function(){
this.$emit('show',this.arr)
}
}
})
new Vue({
el:'.itany'
})
</script>
</body>
</html>
12041882-7b461f24cb046ffa.png
注释：可以把子组件中input的value传递到父组件的p标签中去
练习2：制作一个聊天对话框
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>对话框</title>
</head>
<body>
<div class="itany">
<father></father>
</div>
<script src="vue.js"></script>
<script>
Vue.component('father', {
template: `
<div>
<ul>
<li v-for="(value,index) in one">{{value}}</li>
</ul>
<child @show="the" userName='jack'></child>
<child @show="the" userName='roce'></child>
</div>
`
, data: function () {
return {
one:[]
}
}
, methods: {
the: function (txt) {
this.one.push(txt)
}
}
})
Vue.component('child', {
props:['userName'],
template: `
<div>
<label>{{userName}}</label>
<input type="text" v-model="arr">
<button @click="add">发送</button>
</div>
`
, data: function () {
return {
arr: ''
}
}
, methods: {
add: function () {
this.$emit('show',this.userName+':'+this.arr);
this.arr=""
}
}
})
new Vue({
el: ".itany"
})
</script>
</body>
</html>
点击前：
12041882-5f528891b9ce931a.png
点击后：
12041882-f8651d0a28026603.png
