js里面设置DOM节点透明度的函数属性：filter= "alpha(opacity=" + value+ ")"（兼容ie）和opacity=value/100（兼容FF和GG）。
先来看看设置透明度的兼容性代码：
function setOpacity(ele, opacity) {
if (ele.style.opacity != undefined) {
///兼容FF和GG和新版本IE
ele.style.opacity = opacity / 100;
} else {
///兼容老版本ie
ele.style.filter = "alpha(opacity=" + opacity + ")";
}
}
关于有的小伙伴这样写：
function setOpacity(ele, opacity) {
if (document.all) {
///兼容ie
ele.style.filter = "alpha(opacity=" + opacity + ")";
}
ele {
///兼容FF和GG
ele.style.opacity = opacity / 100;
}
}
我想说这样在IE10下运行有问题，点了之后没反应。因为IE10支持opacity属性不支持filter了，这个方法不可取。
fadein 函数代码：
function fadein(ele, opacity, speed) {
if (ele) {
var v = ele.style.filter.replace("alpha(opacity=", "").replace(")", "") || ele.style.opacity;
v < 1 && (v = v * 100);
var count = speed / 1000;
var avg = count < 2 ? (opacity / count) : (opacity / count - 1);
var timer = null;
timer = setInterval(function() {
if (v < opacity) {
v += avg;
setOpacity(ele, v);
} else {
clearInterval(timer);
}
}, 500);
}
}
fadeout 函数代码：
function fadeout(ele, opacity, speed) {
if (ele) {
var v = ele.style.filter.replace("alpha(opacity=", "").replace(")", "") || ele.style.opacity || 100;
v < 1 && (v = v * 100);
var count = speed / 1000;
var avg = (100 - opacity) / count;
var timer = null;
timer = setInterval(function() {
if (v - avg > opacity) {
v -= avg;
setOpacity(ele, v);
} else {
clearInterval(timer);
}
}, 500);
}
}
下面给一个demo示例：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<script type="text/javascript" src="fade.js"></script>
<script type="text/javascript">
window.onload = function () {
document.getElementById('Button1').onclick = function () {
fadeout(document.getElementById('DV'), 0, 6000);
}
document.getElementById('Button2').onclick = function () {
fadein(document.getElementById('DV'), 80, 6000);
}
}
</script>
</head>
<body>
<div id="DV" style="background-color: green; width: 400px; height: 400px;"></div>
<input id="Button1" type="button" value="button" />
<input id="Button2" type="button" value="button" />
</body>
</html>
有什么更好的实现方式可以留言。。。