javascript实现倒计时提示框

Z时代
2024-01-10
分类：IT

本文实例为大家分享了javascript实现倒计时提示框的具体代码，供大家参考，具体内容如下

代码：


<!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>全屏提示框</title>
 <style>
  #button{
   width: 150px;
   height: 50px;
   background-color: greenyellow;
  }
  .fullScreenDiv{/* 全屏div */
   display: none;
   position: absolute;
   left: 0px;
   top: 0px;
   width: 100%;
   height: 100%;
   background-color: rgba(0, 0, 0, 0.4);
  }
  .promptDiv{/* 提示框div */
   display: none;
   position: absolute;
   left: 50%;
   top: 50%;
   transform: translateX(-50%) translateY(-50%);
   width: 30%;
   height: 30%;
   border-radius: 20px;
   background-color:white;
   text-align: center;
  }
  .close{
   height: 34px;
   line-height: 34px;
   margin: 0px;
   text-align: right;
   border-top-left-radius: 20px;
   border-top-right-radius: 20px;
   background-color: cornflowerblue
  }
  .X{
   padding: 2px 6px;
   margin-right: 8px;
   color: white;
   cursor: pointer;
  }
  .countDown{/*倒计时关闭提示框*/
   color: red;
   font-size: 28px;
  }
 </style>
 <script>
  window.onload=function(){
   document.getElementById("button").addEventListener("click",function(){
    document.getElementsByClassName("fullScreenDiv")[0].style.display="block";
    document.getElementsByClassName("promptDiv")[0].style.display="block";
     for(var i=5;i>=0;i--){
      (function(i){
       setTimeout(function(){
       var j=Math.abs(i-5);//如果i为0，那么被定时0s，则要输出abs(0-5)=5 ,如果i为5，那么被定时5s，则要输出abs(i-5)=0   
       if(j==0){
   document.getElementsByClassName("fullScreenDiv")[0].style.display="none";
        document.getElementsByClassName("promptDiv")[0].style.display="none";
        }else{
        document.getElementsByClassName("countDown")[0].innerHTML=j;
        }  
        },i*1000);//每次间隔时间为1s
       })(i); 
      }
    });
     document.getElementsByClassName("X")[0].addEventListener("click",function(){
      document.getElementsByClassName("fullScreenDiv")[0].style.display="none";
      document.getElementsByClassName("promptDiv")[0].style.display="none";
     }); 
  }
 </script>
</head>
<body>
 <div>
  <button id="button">打开全屏提示框</button>
 </div>
 <div class="fullScreenDiv">
  <div class="promptDiv">
   <h4 class="close"><span class="X">X</span></h4>
    <p>我是全屏提示框我是全屏提示框我是全屏提示框</p>
    <p>倒计时关闭</p>
    <span class="countDown">5</span>
  </div>
 </div>
</body>
</html>