VUE组件 之 倒计时（防刷新）

思路：

一、效果图：

二、CSS代码

.box{
width: 300px;
height: 100px;
line-height: 100px;
margin: 100px auto;
background-color: #eee;
text-align: center;
font-size: 30px;
color: #666;
}
.count-number{
color: red;
font-size: 30px;
font-weight: bold;
}

三、HTML代码

<div class="wrap">
<countdown seconds="15" index="1"></countdown>
<countdown seconds="30" index="2"></countdown>
</div>

四、JAVASCRIPT代码

// 倒计时组件
Vue.component('countdown', {
props: ['seconds', 'index'],
data: () => {
return {
timerCount: 0
}
},
mounted() {
this.timing();
},
methods: {
timing() {
let startTime = localStorage.getItem(`startTime${this.index}`);
let nowTime = new Date().getTime();
if(startTime) {
let surplus = this.seconds - parseInt((nowTime-startTime) / 1000, 10);
this.timerCount = surplus <= 0 ? 0 : surplus;
} else {
this.timerCount = this.seconds;
localStorage.setItem(`startTime${this.index}`, nowTime);
}

let timer = setInterval(() => {
if(this.timerCount > 0 && this.timerCount <= this.seconds) {
this.timerCount--;
　　  } else {
localStorage.removeItem(`startTime${this.index}`);
clearInterval(timer);
}
}, 1000);
}
},
template: `<div class="box">倒计时 <span class="count-number">{{timerCount < 10 ? '0' + timerCount : timerCount}}</span> 秒</div>`
});

// Vue实例
new Vue({
el: '.wrap'
});