在 ie6 下只有 a 才支援 :hover 偽類,其它標籤都不支援,很是讓人頭疼。不過,可以通過 csshover.htc 可以解決 ie6 的 hover 相容問題。
它利用 javascript 指令碼來給元素的的樣式定義,如果檢測到 hover 定義,就給元素設定 onmouseover 和 onmouseout 事件,以此來實現 hover 的效果。
附上 csshover.htc 代碼:
<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(){ 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>
引用方式:
body{behavior:url(css/csshover.htc);}
需要注意的是引用 htc 的路徑問題:不管你是在 css 檔案裡面引用 htc 檔案,還是 html 裡面引用 htc 檔案,都是 html 檔案去找 htc 的路徑。