不用jQuery实现的动画效果代码

不过随着新版本的升级, 体积也慢慢变大了.
24KB, Minified and Gzipped 155KB, Uncompressed Code
压缩并gzip输出24K, 也不小了.
如果页面上一个简单的效果,一个简单的动画就没必要载入这么大的库.
看下面这个图片渐变效果, 其实纯js不到20行就可以搞定了.
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" /><style type="text/css"></P> <P>body {padding:0; margin:0;}#main {margin: 50px auto;border: 1px solid #ccc;width:700px}#main img {padding:0 20px; border:none; display:none}</style><a href="javascript:;" onclick="showimg('/UploadFiles/2021-04-02/logo.gif');"><img src="/UploadFiles/2021-04-02/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('https://www.jb51.net/images/logo.gif');"><img src="https://www.jb51.net/images/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('/UploadFiles/2021-04-02/logo.gif');"><img src="/UploadFiles/2021-04-02/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('https://www.jb51.net/images/logo.gif');"><img src="https://www.jb51.net/images/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('/UploadFiles/2021-04-02/logo.gif');"><img src="/UploadFiles/2021-04-02/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('https://www.jb51.net/images/logo.gif');"><img src="https://www.jb51.net/images/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('/UploadFiles/2021-04-02/logo.gif');"><img src="/UploadFiles/2021-04-02/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a> <a href="javascript:;" onclick="showimg('https://www.jb51.net/images/logo.gif');"><img src="https://www.jb51.net/images/logo.gif" alt="不用jQuery实现的动画效果代码" onmousewheel="return bbimg(this)" onload="javascript:resizepic(this)" border="0"/></a>
[Ctrl+A 全选 注:引入外部Js需再刷新一下页面才能执行]