jquery學習篇——鼠標通過圖片變灰效果

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>鼠標通過圖片變灰效果 css和jquery</title>
<style type="text/css">
body {
	height: 100%;
	margin: 0;
	padding: 0;
	font: normal 10px Verdana, Arial, Helvetica, sans-serif;
	background: #fff;
	position: relative;
}
h1 {
	text-align: center;
	font-weight: normal;
	font-size: 2.5em;
}
h1 small {
	display: block;
	font-size: 0.7em;
	color: #999;
}
img {border: none;}
ul.gallery {
	width: 708px;
	list-style: none;
	margin: 0 auto; padding: 0;
}
ul.gallery li {
	float: left;
	margin: 10px; padding: 0;
	text-align: center;
	border: 1px solid #ccc;
	-moz-border-radius: 3px; /*--CSS3 Rounded Corners--*/
	-khtml-border-radius: 3px; /*--CSS3 Rounded Corners--*/
	-webkit-border-radius: 3px; /*--CSS3 Rounded Corners--*/
	display: inline; /*--Gimp Fix aka IE6 Fix--*/
}
ul.gallery li a.thumb {
	width: 204px;
	height: 182px;
	padding: 5px;
	border-bottom: 1px solid #ccc;
	cursor: pointer;
}
ul.gallery li span { /*--Used to crop image--*/
	width: 204px;
	height: 182px;
	overflow: hidden;
	display: block;
}
ul.gallery li a.thumb:hover {
	background: #333;
}
ul.gallery li h2 {
	font-size: 1em;
	font-weight: normal;
	text-transform: uppercase;
	margin: 0; padding: 10px;
	background: #f0f0f0;
	border-top: 1px solid #fff; /*--Subtle bevel effect--*/
}
ul.gallery li a {text-decoration: none; color: #777; display: block;}
</style>
<script type="text/javascript" src="jquery.1.3.2.min.js"></script>
<script type="text/javascript">

$(document).ready(function() {
	
	$("ul.gallery li").hover(function() { //On hover...這裏面的this是指ul.gallery li
		
		var thumbOver = $(this).find("img").attr("src"); //Get image url and assign it to 'thumbOver'  attr() 方法設置或返回被選元素的屬性值。也可用於設置屬性。	
		//Set a background image(thumbOver) on the <a> tag 
		$(this).find("a.thumb").css({'background' : 'url(' + thumbOver + ') no-repeat center bottom'});//由於這裏的每一個a裏面的背景不同是動態的,因此須要獲取img裏面的src。
		//Fade the image to 0 
		$(this).find("span").stop().fadeTo('normal', 0 , function() {  //stop() 方法中止當前正在運行的動畫。  fadeIn() 方法使用淡出效果來隱藏被選元素,假如該元素是隱藏的。語法:$(selector).fadeTo(speed,opacity,callback)  speed可選,opacity必填,callback可選。爲fadeTo 函數執行完以後,要執行的函數。
			$(this).hide(); //Hide the image after fade
		}); 
	}//注意這裏。hover裏面須要兩個函數,這裏是第一個函數的範圍。
	, function() { //on hover out...
		//Fade the image to 1 
		$(this).find("span").stop().fadeTo('normal', 1).show();
	});

});
/*--方法:每個img裏面的圖片都包含一個彩色和灰度的圖片,而後將每個img裏面灰度的圖片賦值給a的背景,而後當鼠標通過每個img時,a上面的img就會產生漸隱效果到消失就會跟着露出a的背景,這樣子就感受是動態使背景透出了,感受是鼠標通過把圖片處理成灰白了,其實則否則。呵呵---*/
</script>
</head>
<body>
<h1><a href="http://www.sohtanaka.com/web-design/greyscale-hover-effect-w-css-jquery/" style="color: #333; text-decoration: none;">Greyscale Hover Effect w/ CSS & jQuery</a> <small>Tutorial by <a href="http://www.sohtanaka.com" style="color: #999;">Soh Tanaka</a></small></h1>

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</body>
</html>

轉載於:https://www.cnblogs.com/meimeiwa/archive/2011/06/20/jquery_hover.htmljavascript