浅谈弹性页面布局
??? 今天在博客園看了冰極峰先生的《彈性流體布局》文章，他具體的講解了彈性布局是用到min-width這個屬性,但這個屬性在IE6下不受支持,因此加入了老外的一個JS腳本,這個腳本讓IE6也能支持最小,最大寬度(高度)四個屬性.彈性布局其實最難的還不是布局，而是里面的圖片如何做到自適應，也就是說讓圖片也變得彈性起來。這是這種布局時要最優先考慮的事情。頁頭圖片就是一個彈性圖片的典型應用，你可以縮小一下窗口看看。
????? 其中minmax.js的代碼如下：
// 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 @*/
轉載于:https://www.cnblogs.com/xj0112/archive/2009/05/10/1453749.html
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