03_02.子传父

作者: Robyn_Luo | 来源:发表于2017-11-14 19:11 被阅读0次

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <main id="app">
        <!-- 1 父使用子的时候, 监听子事件 -->
        <app-header v-bind:tit="title" v-on:changecount="change"></app-header>
    </main>

    <script src="vue.js"></script>
    <script>
        Vue.component('app-header', {
            template: `<header>{{ tit }}{{ count }}<button @click="countAdd">点我</button></header>`,
            data: function() {
                return {
                    count: 0
                };
            },
            props: ['tit'],
            methods: {
                countAdd: function() {
                    this.count++;
                    this.$emit('changecount', this.count);  // 2 子在需要的时候触发事件
                }
            }
        });

        var vm = new Vue({
            el: '#app',
            data: {
                title: '登陆'
            },
            methods: {
                change: function(val) {
                    console.log(`接收来自子的值:${val}`);
                }
            }
        });
    </script>
</body>
</html>