1.img 图片内容在不同分辨率下居中显示（如果隐藏多余，在img外面套一个div 设定overflow： hidden。div的大小就是img显示区域的大小）
<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> <style type="text/css"> body,div,p,a,img,ul,ol,li{ margin: 0; padding: 0; } #tab { overflow:hidden;
width:100%;要显示的宽度 } #tab img{ overflow:hidden; width:1920px; height:447px; position: relative;
left:50%; 刚好在中间
margin-left:-960px;图片宽度一半 } #tab>img:not(:first-child){ display:none; } </style> <script> //js幻灯片 window.onload = function(){ var images = document.getElementsByTagName('img'); var pos = 0; var len = images.length; setInterval(function(){ images[pos].style.display = 'none'; pos = ++pos == len ? 0 : pos; images[pos].style.display = 'inline'; },3000); }; </script> </head> <body> <div id="tab"> <img src="images/20160907_100403_003.jpg" width="1920px" height="447"/> <img src="images/20160907_100403_004.jpg" width="1920px" height="447"/> </div> </body> </html>
2.背景 图片内容在不同分辨率下居中显示(演示的图片宽度是1920px，当图片宽度大于显示屏的宽度时)
<div class="index-panel-pic1"></div>
.index-panel-pic1{ background: url(../images/20160907_100403_000.gif) no-repeat center center; width:100%; height:650px; background-size: cover; }