CSS实现onMouseOver、onMouseOut效果和层套菜单

news/2024/5/21 0:35:25/文章来源:https://blog.csdn.net/weixin_33705053/article/details/92674114

在IE中 <a> 标签的。而实际上 WEB 标准里面，应该对所有元素都支持。
如果使用 Mozilla 或者 Opera, 那么可以看到不需要这个 htc 都可以正常运行的。因为 htc 是 IE 特有的，别的浏览器不能理解，会忽略掉，不影响结果的显示。

以下这段 htc 是一个老外写的针对 IE 的 hover 行为的一个修正。
有了这个代码就方便多了，而且最可贵的是，以上的这个页面例子是可以兼容 IE, Mozilla 和 Opera 的。

原先在html里都是使用onMouserOver等事件，实现鼠标焦点控制的，从来没有想到过用CSS简化原先繁琐的工作，直到偶然间发现了whatever:hover，才认识到CSS原来可以做很多工作，甚至可是实现繁杂的menubar。

实现的核心部分是csshover.htc文件，它其实就是JScript代码，负责处理所有的CSS格式，根据定制的CSS格式，生成onMouseOver和onMouseOut事件，实现了hover的组件化。使用时只需制定div:hover{ background:#f8f8f8; }，就实现了鼠标移动到div图层上时，改变背景色的事件。

csshover.htc

<attach event="ondocumentready" handler="parseStylesheets" />
<script language="JScript">
/**
* Pseudos - V1.30.050121 - hover & active
* ---------------------------------------------
* Peterned - http://www.xs4all.nl/~peterned/
* (c) 2005 - Peter Nederlof
*
* Credits - Arnoud Berendsen
* - Martin Reurings
* - Robert Hanson
*
* howt body { behavior:url("csshover.htc"); }
* ---------------------------------------------
*/

var currentSheet, doc = window.document, activators = {
onhover:{on:'onmouseover', off:'onmouseout'},
onactive:{on:'onmousedown', off:'onmouseup'}
}

function parseStylesheets() {
var sheets = doc.styleSheets, l = sheets.length;
for(var i=0; i<l; i++)
parseStylesheet(sheets[i]);
}
function parseStylesheet(sheet) {
if(sheet.imports) {
try {
var imports = sheet.imports, l = imports.length;
for(var i=0; i<l; i++) parseStylesheet(sheet.imports[i]);
} catch(securityException){}
}

try {
var rules = (currentSheet = sheet).rules, l = rules.length;
for(var j=0; j<l; j++) parseC×××ule(rules[j]);
} catch(securityException){}
}

function parseC×××ule(rule) {
var select = rule.selectorText, style = rule.style.cssText;
if(!(/(^|\s)(([^a]([^ ]+)?)|(a([^#.][^ ]+)+)):(hover|active)/i).test(select) || !style) return;

var pseudo = select.replace(/[^:]+:([a-z-]+).*/i, 'on$1');
var newSelect = select.replace(/(\.([a-z0-9_-]+):[a-z]+)|(:[a-z]+)/gi, '.$2' + pseudo);
var className = (/\.([a-z0-9_-]*on(hover|active))/i).exec(newSelect)[1];
var affected = select.replace(/:hover.*$/, '');
var elements = getElementsBySelect(affected);

currentSheet.addRule(newSelect, style);
for(var i=0; i<elements.length; i++)
new HoverElement(elements[i], className, activators[pseudo]);
}

function HoverElement(node, className, events) {
if(!node.hovers) node.hovers = {};
if(node.hovers[className]) return;
node.hovers[className] = true;
node.attachEvent(events.on,
function() { node.className += ' ' + className; });
node.attachEvent(events.off,
function() { node.className =
node.className.replace(new RegExp('\\s+'+className, 'g'),''); });
}

function getElementsBySelect(rule) {
var parts, nodes = [doc];
parts = rule.split(' ');
for(var i=0; i<parts.length; i++) {
nodes = getSelectedNodes(parts[i], nodes);
} return nodes;
}
function getSelectedNodes(select, elements) {
var result, node, nodes = [];
var classname = (/\.([a-z0-9_-]+)/i).exec(select);
var identify = (/\#([a-z0-9_-]+)/i).exec(select);
var tagName = select.replace(/(\.|\#|\:)[a-z0-9_-]+/i, '');
for(var i=0; i<elements.length; i++) {
result = tagName? elements[i].all.tags(tagName):elements[i].all;
for(var j=0; j<result.length; j++) {
node = result[j];
if((identify && node.id != identify[1]) || (classname && !(new RegExp('\\b' +
classname[1] + '\\b').exec(node.className)))) continue;
nodes[nodes.length] = node;
}
} return nodes;
}
</script>

Test.htm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<title> New Document </title>
<meta http-equiv="Content-Type" content="text/html;charset=gb2312">
<meta name="Generator" content="EditPlus">
<meta name="Author" content="Roger Chen">
<meta name="keywords" content="">
<meta name="description" content="">
<style>
body {behavior: url(csshover.htc);}
table#tbl tr:hover {background: #000000; color: #ffffff;}
div.test:hover {background: #000000; color: #ffffff;}
a.test:hover {background: #000000; color: #ffffff;}
input.test2:hover {background: #000000; border: 1px dotted black;}
</style>

<div class="test">haha</div><a href="" class="test">5456456</a>
<p>表格1：</p>
<table id="tbl" border="1" width="100%">
<tr>
<td>OK</td>
<td>yes</td>
<td>no</td>
</tr>
<tr>
<td>haha</td>
<td>fsdfsdf</td>
<td>测试</td>
</tr>
<tr>
<td>木野狐</td>
<td>html/css</td>
<td>javascript</td>
</tr>
</table>
<p>表格2：</p>
<table id="tbl" border="1" width="100%">
<tr>
<td>OK</td>
<td>yes</td>
<td>no</td>
</tr>
<tr>
<td>haha</td>
<td>fsdfsdf</td>
<td>测试</td>
</tr>
<tr>
<td>木野狐</td>
<td>html/css</td>
<td>javascript</td>
</tr>
</table>
<input class="test2">

menubar.htm

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html>
<head>
<title> whatever:hover cssmenu </title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />

<style type="text/css">

body {
behavior:url("csshover.htc");
}

* {
font-family:arial,tahoma,verdana,helvetica;
font-size:12px;
}

/* the menu */

ul,li,a {
display:block;
margin:0;
padding:0;
border:0;
}

ul {
width:150px;
border:1px solid #9d9da1;
background:white;
list-style:none;
}

li {
position:relative;
padding:1px;
padding-left:26px;
background:url("p_w_picpaths/item_moz.gif") no-repeat;
z-index:9;
}
li.folder { background:url("p_w_picpaths/item_folder.gif") no-repeat; }
li.folder ul {
position:absolute;
left:120px; /* IE */
top:5px;
}
li.folder>ul { left:140px; } /* others */

a {
padding:2px;
border:1px solid white;
text-decoration:none;
color:gray;
font-weight:bold;
width:100%; /* IE */
}
li>a { width:auto; } /* others */

li a.submenu {
background:url("p_w_picpaths/sub.gif") right no-repeat;
}

/* regular hovers */

a:hover {
border-color:gray;
background-color:#bbb7c7;
color:black;
}
li.folder a:hover {
background-color:#bbb7c7;
}

/* hovers with specificity */

li.folder:hover { z-index:10; }

ul ul, li:hover ul ul {
display:none;
}

li:hover ul, li:hover li:hover ul {
display:block;
}

</style>

</head>

<body>

<ul id="menu">
<li><a href="#"> lorem </a></li>
<li class="folder">
<a href="#" class="submenu"> adipiscing </a>
<ul>
<li><a href="#"> dolor </a></li>
<li class="folder">
<a href="#" class="submenu"> consectetuer</a>
<ul>
<li><a href="#"> elit </a></li>
<li><a href="#"> ipsum </a></li>
<li><a href="#"> Donec </a></li>
</ul>
</li>
<li><a href="#"> vestibulum </a></li>
</ul>
</li>
<li class="folder">
<a href="#" class="submenu"> consectetuer</a>
<ul>
<li><a href="#"> elit </a></li>
<li><a href="#"> ipsum </a></li>
<li><a href="#"> Donec </a></li>
</ul>
</li>
<li><a href="#"> sit amet </a></li>
</ul>
</body>
</html>