JS实现的透明度渐变动画效果示例

程序员文章站 2022-05-28 12:50:22

本文实例讲述了js实现的透明度渐变动画效果。分享给大家供大家参考，具体如下： <...

本文实例讲述了js实现的透明度渐变动画效果。分享给大家供大家参考，具体如下：

<!doctype html>
<html>
  <head>
  <meta charset="utf-8">
    <title>www.jb51.net js透明度变化效果</title>
    <style>
    body{
      margin: 0px;
      padding: 0px;
    }
    .redb{
      width:200px;
      height: 200px;
      background: red;
      filter:alpha(opacity=30);
      opacity: 0.3;
    }
    </style>
  </head>
  <body>
    <div class="redb" id="opbtn"></div>
    <script>
    window.onload = function(){
      var opdiv = document.getelementbyid("opbtn");
      opdiv.onmouseover = function(){
        startmove(100);
      }
      opdiv.onmouseout = function(){
        startmove(30);
      }
    }
    var timer = null;
    var alpha = 30;
    var speed = 0;
    function startmove(optarget){
      clearinterval(timer);
      var opdiv = document.getelementbyid("opbtn");
      timer = setinterval(function(){
        if(alpha<optarget){
          speed = 10;
        }
        else if(alpha>optarget){
          speed = -10;
        }
        if(alpha==optarget){
          clearinterval(timer);
        }
        else{
          alpha += speed;
          opdiv.style.opacity = alpha/100;
          opdiv.style.filter = 'alpha(opacity='+alpha+')';
        }
      },100);
    }
    </script>
  </body>
</html>

运行效果：

JS实现的透明度渐变动画效果示例