1 切图

2 div{filter:Alpha(Opacity=50);/* IE */-moz-opacity:0.5;/* Moz FF */opacity: 0.5;}


1 图片也可以用gif    

2

注:DD_belatedPNG.js 和 js会产生冲突    所以比如一个tab切换做了效果又做了背景图片透明 一般这个背景要用gif的


/**
* DD_belatedPNG: Adds IE6 support: PNG p_w_picpaths for CSS background-p_w_picpath and HTML .
* Author: Drew Diller
* Email: [email protected]
* URL: http://www.dillerdesign.com/experiment/DD_belatedPNG/
* Version: 0.0.8a
* Licensed under the MIT License: http://dillerdesign.com/experiment/DD_belatedPNG/#license
*
* Example usage:
* DD_belatedPNG.fix('.png_bg'); // argument is a CSS selector
* DD_belatedPNG.fixPng( someNode ); // argument is an HTMLDomElement
**/

/*
PLEASE READ:
Absolutely everything in this script is SILLY.  I know this.  IE's rendering of certain pixels doesn't make sense, so neither does this code!
*/

var DD_belatedPNG = {
   ns: 'DD_belatedPNG',
   imgSize: {},
   delay: 10,
   nodesFixed: 0,
   createVmlNameSpace: function () { /* enable VML */
       if (document.namespaces && !document.namespaces[this.ns]) {
           document.namespaces.add(this.ns, 'urn:schemas-microsoft-com:vml');
       }
   },
   createVmlStyleSheet: function () { /* style VML, enable behaviors */
       /*
           Just in case lots of other developers have added
           lots of other stylesheets using document.createStyleSheet
           and hit the 31-limit mark, let's not use that method!
           further reading: http://msdn.microsoft.com/en-us/library/ms531194(VS.85).aspx
       */
       var screenStyleSheet, printStyleSheet;
       screenStyleSheet = document.createElement('style');
       screenStyleSheet.setAttribute('media', 'screen');
       document.documentElement.firstChild.insertBefore(screenStyleSheet, document.documentElement.firstChild.firstChild);
       if (screenStyleSheet.styleSheet) {
           screenStyleSheet = screenStyleSheet.styleSheet;
           screenStyleSheet.addRule(this.ns + '\\:*', '{behavior:url(#default#VML)}');
           screenStyleSheet.addRule(this.ns + '\\:shape', 'position:absolute;');
           screenStyleSheet.addRule('img.' + this.ns + '_sizeFinder', 'behavior:none; border:none; position:absolute; z-index:-1; top:-10000px; visibility:hidden;'); /* large negative top value for avoiding vertical scrollbars for large p_w_picpaths, suggested by James O'Brien, http://www.thanatopsic.org/hendrik/ */
           this.screenStyleSheet = screenStyleSheet;

           /* Add a print-media stylesheet, for preventing VML artifacts from showing up in print (including preview). */
           /* Thanks to R閙i Pr関ost for automating this! */
           printStyleSheet = document.createElement('style');
           printStyleSheet.setAttribute('media', 'print');
           document.documentElement.firstChild.insertBefore(printStyleSheet, document.documentElement.firstChild.firstChild);
           printStyleSheet = printStyleSheet.styleSheet;
           printStyleSheet.addRule(this.ns + '\\:*', '{display: none !important;}');
           printStyleSheet.addRule('img.' + this.ns + '_sizeFinder', '{display: none !important;}');
       }
   },
   readPropertyChange: function () {
       var el, display, v;
       el = event.srcElement;
       if (!el.vmlInitiated) {
           return;
       }
       if (event.propertyName.search('background') != -1 || event.propertyName.search('border') != -1) {
           DD_belatedPNG.applyVML(el);
       }
       if (event.propertyName == 'style.display') {
           display = (el.currentStyle.display == 'none') ? 'none' : 'block';
           for (v in el.vml) {
               if (el.vml.hasOwnProperty(v)) {
                   el.vml[v].shape.style.display = display;
               }
           }
       }
       if (event.propertyName.search('filter') != -1) {
           DD_belatedPNG.vmlOpacity(el);
       }
   },
   vmlOpacity: function (el) {
       if (el.currentStyle.filter.search('lpha') != -1) {
           var trans = el.currentStyle.filter;
           trans = parseInt(trans.substring(trans.lastIndexOf('=')+1, trans.lastIndexOf(')')), 10)/100;
           el.vml.color.shape.style.filter = el.currentStyle.filter; /* complete guesswork */
           el.vml.p_w_picpath.fill.opacity = trans; /* complete guesswork */
       }
   },
   handlePseudoHover: function (el) {
       setTimeout(function () { /* wouldn't work as intended without setTimeout */
           DD_belatedPNG.applyVML(el);
       }, 1);
   },
   /**
   * This is the method to use in a document.
   * @param {String} selector - REQUIRED - a CSS selector, such as '#doc .container'
   **/
   fix: function (selector) {
       if (this.screenStyleSheet) {
           var selectors, i;
           selectors = selector.split(','); /* multiple selectors supported, no need for multiple calls to this anymore */
           for (i=0; i                this.screenStyleSheet.addRule(selectors[i], 'behavior:expression(DD_belatedPNG.fixPng(this))'); /* seems to execute the function without adding it to the stylesheet - interesting... */
           }
       }
   },
   applyVML: function (el) {
       el.runtimeStyle.cssText = '';
       this.vmlFill(el);
       this.vmlOffsets(el);
       this.vmlOpacity(el);
       if (el.isImg) {
           this.copyImageBorders(el);
       }
   },
   attachHandlers: function (el) {
       var self, handlers, handler, moreForAs, a, h;
       self = this;
       handlers = {resize: 'vmlOffsets', move: 'vmlOffsets'};
       if (el.nodeName == 'A') {
           moreForAs = {mouseleave: 'handlePseudoHover', mouseenter: 'handlePseudoHover', focus: 'handlePseudoHover', blur: 'handlePseudoHover'};
           for (a in moreForAs) {            
               if (moreForAs.hasOwnProperty(a)) {
                   handlers[a] = moreForAs[a];
               }
           }
       }
       for (h in handlers) {
           if (handlers.hasOwnProperty(h)) {
               handler = function () {
                   self[handlers[h]](el);
               };
               el.attachEvent('on' + h, handler);
           }
       }
       el.attachEvent('onpropertychange', this.readPropertyChange);
   },
   giveLayout: function (el) {
       el.style.zoom = 1;
       if (el.currentStyle.position == 'static') {
           el.style.position = 'relative';
       }
   },
   copyImageBorders: function (el) {
       var styles, s;
       styles = {'borderStyle':true, 'borderWidth':true, 'borderColor':true};
       for (s in styles) {
           if (styles.hasOwnProperty(s)) {
               el.vml.color.shape.style[s] = el.currentStyle[s];
           }
       }
   },
   vmlFill: function (el) {
       if (!el.currentStyle) {
           return;
       } else {
           var elStyle, noImg, lib, v, img, imgLoaded;
           elStyle = el.currentStyle;
       }
       for (v in el.vml) {
           if (el.vml.hasOwnProperty(v)) {
               el.vml[v].shape.style.zIndex = elStyle.zIndex;
           }
       }
       el.runtimeStyle.backgroundColor = '';
       el.runtimeStyle.backgroundImage = '';
       noImg = true;
       if (elStyle.backgroundImage != 'none' || el.isImg) {
           if (!el.isImg) {
               el.vmlBg = elStyle.backgroundImage;
               el.vmlBg = el.vmlBg.substr(5, el.vmlBg.lastIndexOf('")')-5);
           }
           else {
               el.vmlBg = el.src;
           }
           lib = this;
           if (!lib.imgSize[el.vmlBg]) { /* determine size of loaded p_w_picpath */
               img = document.createElement('img');
               lib.imgSize[el.vmlBg] = img;
               img.className = lib.ns + '_sizeFinder';
               img.runtimeStyle.cssText = 'behavior:none; position:absolute; left:-10000px; top:-10000px; border:none; margin:0; padding:0;'; /* make sure to set behavior to none to prevent accidental matching of the helper elements! */
               imgLoaded = function () {
                   this.width = this.offsetWidth; /* weird cache-busting requirement! */
                   this.height = this.offsetHeight;
                   lib.vmlOffsets(el);
               };
               img.attachEvent(' imgLoaded);
               img.src = el.vmlBg;
               img.removeAttribute('width');
               img.removeAttribute('height');
               document.body.insertBefore(img, document.body.firstChild);
           }
           el.vml.p_w_picpath.fill.src = el.vmlBg;
           noImg = false;
       }
       el.vml.p_w_picpath.fill.on = !noImg;
       el.vml.p_w_picpath.fill.color = 'none';
       el.vml.color.shape.style.backgroundColor = elStyle.backgroundColor;
       el.runtimeStyle.backgroundImage = 'none';
       el.runtimeStyle.backgroundColor = 'transparent';
   },
   /* IE can't figure out what do when the offsetLeft and the clientLeft add up to 1, and the VML ends up getting fuzzy... so we have to push/enlarge things by 1 pixel and then clip off the excess */
   vmlOffsets: function (el) {
       var thisStyle, size, fudge, makeVisible, bg, bgR, dC, altC, b, c, v;
       thisStyle = el.currentStyle;
       size = {'W':el.clientWidth+1, 'H':el.clientHeight+1, 'w':this.imgSize[el.vmlBg].width, 'h':this.imgSize[el.vmlBg].height, 'L':el.offsetLeft, 'T':el.offsetTop, 'bLW':el.clientLeft, 'bTW':el.clientTop};
       fudge = (size.L + size.bLW == 1) ? 1 : 0;
       /* vml shape, left, top, width, height, origin */
       makeVisible = function (vml, l, t, w, h, o) {
           vml.coordsize = w+','+h;
           vml.coordorigin = o+','+o;
           vml.path = 'm0,0l'+w+',0l'+w+','+h+'l0,'+h+' xe';
           vml.style.width = w + 'px';
           vml.style.height = h + 'px';
           vml.style.left = l + 'px';
           vml.style.top = t + 'px';
       };
       makeVisible(el.vml.color.shape, (size.L + (el.isImg ? 0 : size.bLW)), (size.T + (el.isImg ? 0 : size.bTW)), (size.W-1), (size.H-1), 0);
       makeVisible(el.vml.p_w_picpath.shape, (size.L + size.bLW), (size.T + size.bTW), (size.W), (size.H), 1 );
       bg = {'X':0, 'Y':0};
       if (el.isImg) {
           bg.X = parseInt(thisStyle.paddingLeft, 10) + 1;
           bg.Y = parseInt(thisStyle.paddingTop, 10) + 1;
       }
       else {
           for (b in bg) {
               if (bg.hasOwnProperty(b)) {
                   this.figurePercentage(bg, size, b, thisStyle['backgroundPosition'+b]);
               }
           }
       }
       el.vml.p_w_picpath.fill.position = (bg.X/size.W) + ',' + (bg.Y/size.H);
       bgR = thisStyle.backgroundRepeat;
       dC = {'T':1, 'R':size.W+fudge, 'B':size.H, 'L':1+fudge}; /* these are defaults for repeat of any kind */
       altC = { 'X': {'b1': 'L', 'b2': 'R', 'd': 'W'}, 'Y': {'b1': 'T', 'b2': 'B', 'd': 'H'} };
       if (bgR != 'repeat' || el.isImg) {
           c = {'T':(bg.Y), 'R':(bg.X+size.w), 'B':(bg.Y+size.h), 'L':(bg.X)}; /* these are defaults for no-repeat - clips down to the p_w_picpath location */
           if (bgR.search('repeat-') != -1) { /* now let's revert to dC for repeat-x or repeat-y */
               v = bgR.split('repeat-')[1].toUpperCase();
               c[altC[v].b1] = 1;
               c[altC[v].b2] = size[altC[v].d];
           }
           if (c.B > size.H) {
               c.B = size.H;
           }
           el.vml.p_w_picpath.shape.style.clip = 'rect('+c.T+'px '+(c.R+fudge)+'px '+c.B+'px '+(c.L+fudge)+'px)';
       }
       else {
           el.vml.p_w_picpath.shape.style.clip = 'rect('+dC.T+'px '+dC.R+'px '+dC.B+'px '+dC.L+'px)';
       }
   },
   figurePercentage: function (bg, size, axis, position) {
       var horizontal, fraction;
       fraction = true;
       horizontal = (axis == 'X');
       switch(position) {
           case 'left':
           case 'top':
               bg[axis] = 0;
               break;
           case 'center':
               bg[axis] = 0.5;
               break;
           case 'right':
           case 'bottom':
               bg[axis] = 1;
               break;
           default:
               if (position.search('%') != -1) {
                   bg[axis] = parseInt(position, 10) / 100;
               }
               else {
                   fraction = false;
               }
       }
       bg[axis] = Math.ceil(  fraction ? ( (size[horizontal?'W': 'H'] * bg[axis]) - (size[horizontal?'w': 'h'] * bg[axis]) ) : parseInt(position, 10)  );
       if (bg[axis] % 2 === 0) {
           bg[axis]++;
       }
       return bg[axis];
   },
   fixPng: function (el) {
       el.style.behavior = 'none';
       var lib, els, nodeStr, v, e;
       if (el.nodeName == 'BODY' || el.nodeName == 'TD' || el.nodeName == 'TR') { /* elements not supported yet */
           return;
       }
       el.isImg = false;
       if (el.nodeName == 'IMG') {
           if(el.src.toLowerCase().search(/\.png$/) != -1) {
               el.isImg = true;
               el.style.visibility = 'hidden';
           }
           else {
               return;
           }
       }
       else if (el.currentStyle.backgroundImage.toLowerCase().search('.png') == -1) {
           return;
       }
       lib = DD_belatedPNG;
       el.vml = {color: {}, p_w_picpath: {}};
       els = {shape: {}, fill: {}};
       for (v in el.vml) {
           if (el.vml.hasOwnProperty(v)) {
               for (e in els) {
                   if (els.hasOwnProperty(e)) {
                       nodeStr = lib.ns + ':' + e;
                       el.vml[v][e] = document.createElement(nodeStr);
                   }
               }
               el.vml[v].shape.stroked = false;
               el.vml[v].shape.appendChild(el.vml[v].fill);
               el.parentNode.insertBefore(el.vml[v].shape, el);
           }
       }
       el.vml.p_w_picpath.shape.fillcolor = 'none'; /* Don't show blank white shapeangle when waiting for p_w_picpath to load. */
       el.vml.p_w_picpath.fill.type = 'tile'; /* Makes p_w_picpath show up. */
       el.vml.color.fill.on = false; /* Actually going to apply vml element's style.backgroundColor, so hide the whiteness. */
       lib.attachHandlers(el);
       lib.giveLayout(el);
       lib.giveLayout(el.offsetParent);
       el.vmlInitiated = true;
       lib.applyVML(el); /* Render! */
   }
};
try {
   document.execCommand("BackgroundImageCache", false, true); /* TredoSoft Multiple IE doesn't like this, so try{} it */
} catch(r) {}
DD_belatedPNG.createVmlNameSpace();
DD_belatedPNG.createVmlStyleSheet();