今天遇到一个简单的小功能，看网上的一些方法感觉不太适合，所以就手敲了一个，直接上代码！！！

1 import React, { Component } from 'react'; 2  3 class NoTimeContent extends Component { 4     constructor(props) { 5         super(props) 6         this.state = { 7             day: 0, 8             hour: 0, 9             minute: 0,10             second: 011         }12     }13     render() {14         return (15             
     
      16                 
      
17                     限时秒杀18                     {
   this.state.day}天 {
   this.state.hour}:{
   this.state.minute}:{
   this.state.second}19                 
20             
     21         )22     }23 24 componentDidMount() {25       const end = Date.parse(new Date('2018-11-29 24:00'))26       this.countFun(end);27     }28   29   //卸载组件取消倒计时30   componentWillUnmount(){31     clearInterval(this.timer);32   }33   34   countFun = (end) => {35 36     let now_time = Date.parse(new Date());37     var remaining = end - now_time;38  39     this.timer = setInterval(() => {40         //防止出现负数41       if (remaining > 1000) {42         remaining -= 1000;43         let day = Math.floor((remaining / 1000 / 3600) / 24);44         let hour = Math.floor((remaining / 1000 / 3600) % 24);45         let minute = Math.floor((remaining / 1000 / 60) % 60);46         let second = Math.floor(remaining / 1000 % 60);47 48         this.setState({49             day:day,50             hour:hour < 10 ? "0" + hour : hour,51             minute:minute < 10 ? "0" + minute : minute,52             second:second < 10 ? "0" + second : second53         })54       } else {55         clearInterval(this.timer);56         //倒计时结束时触发父组件的方法57         //this.props.timeEnd();58       }59     }, 1000);60   }61 62 }63 export default NoTimeContent;