Vue之生命周期函数详解

 <div id="root">
        <h2 :style="{opacity}"> 欢迎学习Vue的生命周期</h2>
        <button @click="stop">点我停止变化</button>

    </div>
    <script>
        Vue.config.productionTip = false;
        const vm = new Vue({
            el: '#root',
            data: {
                opacity: 1,
            },
            methods: {
                stop() {
                    // clearInterval(this.timer)
                    this.$destroy();
                }
            },
            //Vue完成模板解析并把真实的初始DOM元素放入页面后（挂载完毕）调用mounted
            mounted() {

                this.timer = setInterval(() => {
                    this.opacity -= 0.01;
                    if (this.opacity <= 0)
                        this.opacity = 1;

                }, 16)
            },
            beforeDestroy() {
                console.log('vm即将驾鹤西游了');
                clearInterval(this.timer)
            }
        })
    </script>