本文实例讲述了JavaScript淡入淡出渐变的实现方法。分享给大家供大家参考。具体如下：
这里介绍JavaScript淡入淡出的文字渐变例子，用js来控制div标签元素实现渐变显示，渐变隐藏，只要在那个标签里的内容，都可以淡入淡出，代码简单，便于修改完善，前端设计者必备的网页特效。
运行效果如下图所示：
具体代码如下：
<!DOCTYPE html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>js代码控制元素简单的淡入淡出效果</title>
<style>
* {margin:0; padding:0}
body {font:12px Verdana,Arial; color:#777; background:#222}
a {color:#999; text-decoration:none}
a:hover {color:#bbb}
#wrapper {width:500px; margin:75px auto}
#buttons {height:35px}
.button {border:1px solid #eee; background:#ccc; border-radius:3px; -moz-border-radius:3px; padding:4px 0 5px; width:245px; text-align:center; cursor:pointer; float:left; color:#555}
.button:hover {border:1px solid #fff; background:#d9d9d9; color:#333}
.floatright {float:right}
#fade {opacity:0; filter:alpha(opacity='0') border-radius:3px; -moz-border-radius:3px; margin-bottom:10px; padding:9px 10px 0; height:26px; border:1px solid #548954; background:#355c33; color:#79af72; text-shadow:1px 1px #21341d}
</style>
<script type="text/javascript">
var fadeEffect=function(){
return{
init:function(id, flag, target){
this.elem = document.getElementById(id);
clearInterval(this.elem.si);
this.target = target ? target : flag ? 100 : 0;
this.flag = flag || -1;
this.alpha = this.elem.style.opacity ? parseFloat(this.elem.style.opacity) * 100 : 0;
this.si = setInterval(function(){fadeEffect.tween()}, 20);
},
tween:function(){
if(this.alpha == this.target){
clearInterval(this.si);
}else{
var value = Math.round(this.alpha + ((this.target - this.alpha) * .05)) + (1 * this.flag);
this.elem.style.opacity = value / 100;
this.elem.style.filter = 'alpha(opacity=' + value + ')';
this.alpha = value
}
}
}
}();
</script>
</head>
<body>
<div id="wrapper">
<div id="fade">JavaScript淡入淡出渐变例子</div>
<div id="buttons">
<div class="button" onclick="fadeEffect.init('fade', 1)">Fade In</div>
<div class="button floatright" onclick="fadeEffect.init('fade', 0)">Fade Out</div>
</div>
<p>For more information visit 样式版权所有.<br />
</p>
</div>
</body>
</html>
希望本文所述对大家的javascript程序设计有所帮助。
