js学习进阶-页面覆盖

Posted 2020-08-20 HeroBo

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了js学习进阶-页面覆盖相关的知识，希望对你有一定的参考价值。

页面覆盖以显示一条信息，照片或者常见的登录，广告，

实例：

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
  <style>
    .overlay{
      background-color:#000;
      opacity:.5;
      filter:alpha(opacity=50);
      position:fixed;
      top:0;left:0;
      width:100%;height:100%;
      z-index:10;
    }
    .overlaymsg{
      position:absolute;
      background-color:yellow;
      padding:10px;
      width:200px;
      height:200px;
      font-size:2em;
      z-index:11;
      top:50%;
      left:50%;
      margin-left:-100px;
      margin-top:-100px;
    }
  </style>
  <script>
     function displayPopup(){
       
       var overlay = document.createElement("div");
       overlay.setAttribute("id","overlay");
       overlay.setAttribute("class","overlay");
       document.body.appendChild(overlay);
       
       var msg = document.createElement("div");
       var txt = document.createTextNode("please join our mailing list!(click to close)");
       msg.appendChild(txt);
       msg.setAttribute("id","msg");
       msg.setAttribute("class","overlaymsg");
       
       msg.onclick = restore;
       document.body.appendChild(msg);
     }
    
    function restore(){
      document.body.removeChild(document.getElementById("overlay"));
      document.body.removeChild(document.getElementById("msg"));
      
    }
    
    window.onload = function(){
      displayPopup();
    }
  </script>
</head>
<body>
<p>Existing material.</p>
</body>
</html>