[小知识点]IE6下不支持:hover的解决方法

在网上百度到的解决办法，感觉不错，和大家分享一下。

在CSS样式里加一句代码“body{behavior:url("文件夹/csshover.htc");}”即可。

csshover.htc文件可以在网上搜索下载，也可以自己建立，文件具体内容如下：

<attach event="ondocumentready" handler="parseStylesheets" />

<script language="JScript">

var currentSheet, doc = window.document, activators = {

onhover:{on:'onmouseover', off:'onmouseout'},

onactive:{on:'onmousedown', off:'onmouseup'}

}

function parseStylesheets() {

//window.alert("hi");

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++) parseCSSRule(rules[j]);

   } catch(securityException){}

}

function parseCSSRule(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>