首先看我们的<img>标签代码：<img src="Example.png" border="0" alt="放大镜" />我们将利用IE中特有的特效来满足这个要求，这就是AlphaImageLoader Filter (http://msdn.microsoft.com/library/default.asp?url=/workshop/author/filter/reference/filters/alphaimageloader.asp) 如何做？将下面代码保存为correctPNG.js:
代码如下:
function correctPNG()
{
for(var i=0; i<document.images.length; i++)
{
var img = document.images[i]
var imgName = img.src.toUpperCase()
if (imgName.substring(imgName.length-3, imgName.length) == "PNG")
{
var imgID = (img.id) ? "id=\'" + img.id + "\' " : ""
var imgClass = (img.className) ? "class=\'" + img.className + "\' " : ""
var imgTitle = (img.title) ? "title=\'" + img.title + "\' " : "title=\'" + img.alt + "\' "
var imgStyle = "display:inline-block;" + img.style.cssText
if (img.align == "left") imgStyle = "float:left;" + imgStyle
if (img.align == "right") imgStyle = "float:right;" + imgStyle
if (img.parentElement.href) imgStyle = "cursor:hand;" + imgStyle
var strNewHTML = "<span " + imgID + imgClass + imgTitle
+ " style=\"" + "width:" + img.width + "px; margin:6px; height:" + img.height + "px;" + imgStyle + ";"
+ "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader"
+ "(src=\\'" + img.src + "\\', sizingMethod=\'scale\');\"></span>"
img.outerHTML = strNewHTML
i = i-1
}
}
}
window.attachEvent("onload", correctPNG);
然后在你需要透明的网页中的<head>....</head>区加入：<script type="text/javascript" src="correctPNG.js"></script>
在<body>区加入多个与<img src="Example.png" border="0" alt="放大镜" />类似的PNG图片，试试看？
另一种方法：
代码如下:
<html>
<head>
<title>alpha image</title>
<style type="text/css">
.pngholder{
width:100px;
height:100px;
filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src=\'http://www.jb51.net/attachments/200510/03_124401_ie.png\');
}
.pngalpha{
filter:progid:DXImageTransform.Microsoft.Alpha(opacity=0);
background:url(http://www.jb51.net/attachments/200510/03_124401_ie.png) no-repeat;
width:100px;
height:100px;
}
</style>
</head>
<body bgcolor="#3399ff#">
<!- And this is your code to implement the image ->
<div>透明</div>
<div class="pngholder"><div class="pngalpha"></div></div>
<div>不透明</div>
<img src="http://www.jb51.net/attachments/200510/03_124401_ie.png"/>
</body>
</html>