我们在上一篇说过[cref 42 IE6不支持PNG-24]，同样的[cref 30 bug]还有很多，本文介绍了用 Javascript 修复IE6 及其以下版本不支持 CSS 中 min/max-width/height 属性的方法。
// 说明：让 IE6 及其以下版本支持 CSS 中 min/max-width/height 属性 // 整理：http://www.codebit.cn // minmax.js: make IE5+/Win support CSS min/max-width/height // version 1.0, 08-Aug-2003 // written by Andrew Clover <and@doxdesk.com>, use freely /*@cc_on @if (@_win32 && @_jscript_version>4) var minmax_elements; minmax_props= new Array( new Array('min-width', 'minWidth'), new Array('max-width', 'maxWidth'), new Array('min-height','minHeight'), new Array('max-height','maxHeight') ); // Binding. Called on all new elements. If <body>, initialise; check all // elements for minmax properties function minmax_bind(el) { var i, em, ms; var st= el.style, cs= el.currentStyle; if (minmax_elements==window.undefined) { // initialise when body element has turned up, but only on IE if (!document.body || !document.body.currentStyle) return; minmax_elements= new Array(); window.attachEvent('onresize', minmax_delayout); // make font size listener em= document.createElement('div'); em.setAttribute('id', 'minmax_em'); em.style.position= 'absolute'; em.style.visibility= 'hidden'; em.style.fontSize= 'xx-large'; em.style.height= '5em'; em.style.top='-5em'; em.style.left= '0'; if (em.style.setExpression) { em.style.setExpression('width', 'minmax_checkFont()'); document.body.insertBefore(em, document.body.firstChild); } } // transform hyphenated properties the browser has not caught to camelCase for (i= minmax_props.length; i-->0;) if (cs[minmax_props[i][0]]) st[minmax_props[i][1]]= cs[minmax_props[i][0]]; // add element with properties to list, store optimal size values for (i= minmax_props.length; i-->0;) { ms= cs[minmax_props[i][1]]; if (ms && ms!='auto' && ms!='none' && ms!='0' && ms!='') { st.minmaxWidth= cs.width; st.minmaxHeight= cs.height; minmax_elements[minmax_elements.length]= el; // will need a layout later minmax_delayout(); break; } } } // check for font size changes var minmax_fontsize= 0; function minmax_checkFont() { var fs= document.getElementById('minmax_em').offsetHeight; if (minmax_fontsize!=fs && minmax_fontsize!=0) minmax_delayout(); minmax_fontsize= fs; return '5em'; } // Layout. Called after window and font size-change. Go through elements we // picked out earlier and set their size to the minimum, maximum and optimum, // choosing whichever is appropriate // Request re-layout at next available moment var minmax_delaying= false; function minmax_delayout() { if (minmax_delaying) return; minmax_delaying= true; window.setTimeout(minmax_layout, 0); } function minmax_stopdelaying() { minmax_delaying= false; } function minmax_layout() { window.setTimeout(minmax_stopdelaying, 100); var i, el, st, cs, optimal, inrange; for (i= minmax_elements.length; i-->0;) { el= minmax_elements[i]; st= el.style; cs= el.currentStyle; // horizontal size bounding st.width= st.minmaxWidth; optimal= el.offsetWidth; inrange= true; if (inrange && cs.minWidth && cs.minWidth!='0' && cs.minWidth!='auto' && cs.minWidth!='') { st.width= cs.minWidth; inrange= (el.offsetWidth<optimal); } if (inrange && cs.maxWidth && cs.maxWidth!='none' && cs.maxWidth!='auto' && cs.maxWidth!='') { st.width= cs.maxWidth; inrange= (el.offsetWidth>optimal); } if (inrange) st.width= st.minmaxWidth; // vertical size bounding st.height= st.minmaxHeight; optimal= el.offsetHeight; inrange= true; if (inrange && cs.minHeight && cs.minHeight!='0' && cs.minHeight!='auto' && cs.minHeight!='') { st.height= cs.minHeight; inrange= (el.offsetHeight<optimal); } if (inrange && cs.maxHeight && cs.maxHeight!='none' && cs.maxHeight!='auto' && cs.maxHeight!='') { st.height= cs.maxHeight; inrange= (el.offsetHeight>optimal); } if (inrange) st.height= st.minmaxHeight; } } // Scanning. Check document every so often until it has finished loading. Do // nothing until <body> arrives, then call main init. Pass any new elements // found on each scan to be bound var minmax_SCANDELAY= 500; function minmax_scan() { var el; for (var i= 0; i<document.all.length; i++) { el= document.all[i]; if (!el.minmax_bound) { el.minmax_bound= true; minmax_bind(el); } } } var minmax_scanner; function minmax_stop() { window.clearInterval(minmax_scanner); minmax_scan(); } minmax_scan(); minmax_scanner= window.setInterval(minmax_scan, minmax_SCANDELAY); window.attachEvent('onload', minmax_stop); @end @*/ |
由于只有 IE6 及其以下版本不支持min/max-width/height 属性，因此，我们可以用下面的调用方式：
<!--[if lt IE 7]> <script type="text/javascript" src="minmax.js"></script> <![endif]--> |
在IE中height其实可以理解为min-height
min-height: 23px;
_height: 23px;
在IE中也可以通过overflow: hidden代替max-height
height: 300px;
max-height: 300px;
overflow: hidden;
不需要那么一大段JS这么麻烦。