<template> 
 <span :endTime="endTime" :callback="callback" :endText="endText"> 
  <slot> 
   {{content}} 
  </slot> 
 </span> 
</template> 
<script> 
 export default { 
  data(){ 
   return { 
   content: '', 
   } 
  }, 
  props:{ 
   endTime:{ 
    type: String, 
    default :'' 
   }, 
   endText:{ 
    type : String, 
    default:'已结束' 
   }, 
   callback : { 
    type : Function, 
    default :'' 
   } 
  }, 
  mounted () { 
   this.countdowm(this.endTime) 
  }, 
  methods: { 
   countdowm(timestamp){ 
   let self = this; 
   let timer = setInterval(function(){ 
    let nowTime = new Date(); 
    let endTime = new Date(timestamp * 1000); 
    let t = endTime.getTime() - nowTime.getTime(); 
    if(t>0){ 
     let day = Math.floor(t/86400000); 
     let hour=Math.floor((t/3600000)%24); 
     let min=Math.floor((t/60000)%60); 
     let sec=Math.floor((t/1000)%60); 
     hour = hour < 10 "0" + hour : hour; 
     min = min < 10 "0" + min : min; 
     sec = sec < 10 "0" + sec : sec; 
     let format = ''; 
     if(day > 0){ 
      format = `${day}天${hour}小时${min}分${sec}秒`; 
     }  
     if(day <= 0 && hour > 0 ){ 
      format = `${hour}小时${min}分${sec}秒`;  
     } 
     if(day <= 0 && hour <= 0){ 
      format =`${min}分${sec}秒`; 
     } 
     self.content = format; 
     }else{ 
      clearInterval(timer); 
      self.content = self.endText; 
      self._callback(); 
     } 
     },1000); 
    }, 
    _callback(){ 
    if(this.callback && this.callback instanceof Function){ 
      this.callback(...this); 
     } 
   } 
  } 
 } 
</script>

<count-down endTime="1590761620" :callback="callback" endText="已经结束了"></count-down> 
methods:{
callback:function(){
}
}