<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>DIV CSS遮罩层</title> <script language="javascript" type="text/javascript"> function showdiv() { document.getElementById("bg").style.display ="block"; document.getElementById("show").style.display ="block"; } function hidediv() { document.getElementById("bg").style.display ='none'; document.getElementById("show").style.display ='none'; } </script> <style type="text/css"> #bg { display: none; position: absolute; top: 0%; left: 0%; width: 100%; height: 100%; background-color: black; z-index: 1001; -moz-opacity: 0.7; opacity: .70; filter: alpha(opacity=70); } #show { display: none; position: absolute; top: 25%; left: 22%; width: 53%; height: 49%; padding: 8px; border: 8px solid #E8E9F7; background-color: white; z-index: 1002; overflow: auto; } body { padding-top: 100px; } </style> </head> <body> <input id="btnshow" type="button" value="Show" onclick="showdiv();"/> <div id="bg"></div> <div id="show">测试 <input id="btnclose" type="button" value="Close" onclick="hidediv();"/> </div> </body> </html>
发现当有滚动条时就出现问题了。
经过改动的代码如下
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>DIV CSS遮罩层</title> <script src="js/jquery-1.11.3.min.js"></script> <script language="javascript" type="text/javascript"> function showdiv() { document.getElementById("bg").style.display ="block"; document.getElementById("show").style.display ="block"; $('body').css("overflow", "hidden") } function hidediv() { document.getElementById("bg").style.display = 'none'; document.getElementById("show").style.display = 'none'; $('body').css("overflow", "auto") } </script> <style type="text/css"> #bg { display: none; position: fixed; top: 0; left: 0; bottom: 0; right: 0; background-color: black; z-index: 1001; -moz-opacity: 0.7; opacity: .70; filter: alpha(opacity=70); } #show { display: none; position: absolute; top: 25%; left: 22%; width: 53%; height: 49%; padding: 8px; border: 8px solid #E8E9F7; background-color: white; z-index: 1002; overflow: auto; } body { padding-top: 300px; } </style> </head> <body> <input id="btnshow" type="button" value="Show" onclick="showdiv();"/> <div id="bg"></div> <div id="show">测试 <input id="btnclose" type="button" value="Close" onclick="hidediv();"/> </div> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br><br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br><br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br><br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br><br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br><br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> </body> </html>
完美解决。
从上面的问题中我们总结出以上两条经验。
1、fixed的的作用是
overflow:hidden。才有效，如果页面有滚动条，fixed的意义是不存在的。这是fixed的bug
2、让一个层在body中全部占满有下面的方式
1、left:0;top:0;100%;height:100%；position:fixed
2、left:0;top:0;right：0；bottom：0；posioton:fixed;
非常感谢下面博主的链接问题才得以解决，感谢互联网时代的分享精神。
http://www.cnblogs.com/kaisela/archive/2014/05/21/3740898.html