本文實例講述了js仿土豆網帶縮略圖的焦點圖片切換效果實現方法。分享給大家供大家參考。具體實現方法如下：
復制代碼 代碼如下:<!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>仿土豆網帶縮略圖的焦點圖片切換效果</title>
<style type="text/css">
/* Reset style */
* { margin:0; padding:0; word-break:break-all; }
body { background:#FFF; color:#333; font:12px/1.6em Helvetica, Arial, sans-serif; }
h1, h2, h3, h4, h5, h6 { font-size:1em; }
a { color:#039; text-decoration:none; }
a:hover { text-decoration:underline; }
ul, li { list-style:none; }
fieldset, img { border:none; }
em, strong, cite, th { font-style:normal; font-weight:normal; }
/* Focus_change style */
#focus_change { position:relative; width:450px; height:295px; overflow:hidden; margin:20px 0 1px 60px; }
#focus_change_list { position:absolute; width:1800px; height:295px; }
#focus_change_list li { float:left; }
#focus_change_list li img { width:450px; height:295px; }
.focus_change_opacity { position:absolute; width:450px; height:70px; top:225px; left:0; background:#000; filter:alpha(opacity=50); -moz-opacity:0.5; opacity: 0.5; }
#focus_change_btn { position:absolute; width:450px; height:65px; top:225px; left:0; }
#focus_change_btn ul { padding-left:5px; }
#focus_change_btn li { display:inline; float:left; margin:0 15px; padding-top:12px; }
#focus_change_btn li img { width:76px; height:50px; border:2px solid #888; }
#focus_change_btn .current { background:url(/uploadfile/200901/1/6C164133877.gif) no-repeat 37px 8px;}
#focus_change_btn .current img { border-color:#EEE; }
</style>
<script type="text/javascript">
function $(id) { return document.getElementById(id); }
function moveElement(elementID,final_x,final_y,interval) {
if (!document.getElementById) return false;
if (!document.getElementById(elementID)) return false;
var elem = document.getElementById(elementID);
if (elem.movement) {
clearTimeout(elem.movement);
}
if (!elem.style.left) {
elem.style.left = "0px";
}
if (!elem.style.top) {
elem.style.top = "0px";
}
var xpos = parseInt(elem.style.left);
var ypos = parseInt(elem.style.top);
if (xpos == final_x && ypos == final_y) {
return true;
}
if (xpos < final_x) {
var dist = Math.ceil((final_x - xpos)/10);
xpos = xpos + dist;
}
if (xpos > final_x) {
var dist = Math.ceil((xpos - final_x)/10);
xpos = xpos - dist;
}
if (ypos < final_y) {
var dist = Math.ceil((final_y - ypos)/10);
ypos = ypos + dist;
}
if (ypos > final_y) {
var dist = Math.ceil((ypos - final_y)/10);
ypos = ypos - dist;
}
elem.style.left = xpos + "px";
elem.style.top = ypos + "px";
var repeat = "moveElement('"+elementID+"',"+final_x+","+final_y+","+interval+")";
elem.movement = setTimeout(repeat,interval);
}
function classNormal(){
var focusBtnList = $('focus_change_btn').getElementsByTagName('li');
for(var i=0; i<focusBtnList.length; i++) {
focusBtnList[i].className='';
}
}
function focusChange() {
var focusBtnList = $('focus_change_btn').getElementsByTagName('li');
focusBtnList[0].onmouseover = function() {
moveElement('focus_change_list',0,0,5);
classNormal()
focusBtnList[0].className='current'
}
focusBtnList[1].onmouseover = function() {
moveElement('focus_change_list',-450,0,5);
classNormal()
focusBtnList[1].className='current'
}
focusBtnList[2].onmouseover = function() {
moveElement('focus_change_list',-900,0,5);
classNormal()
focusBtnList[2].className='current'
}
focusBtnList[3].onmouseover = function() {
moveElement('focus_change_list',-1350,0,5);
classNormal()
focusBtnList[3].className='current'
}
}
setInterval('autoFocusChange()', 5000);
var atuokey = false;
function autoFocusChange() {
$('focus_change').onmouseover = function(){atuokey = true}
$('focus_change').onmouseout = function(){atuokey = false}
if(atuokey) return;
var focusBtnList = $('focus_change_btn').getElementsByTagName('li');
for(var i=0; i<focusBtnList.length; i++) {
if (focusBtnList[i].className == 'current') {
var currentNum = i;
}
}
if (currentNum==0 ){
moveElement('focus_change_list',-450,0,5);
classNormal()
focusBtnList[1].className='current'
}
if (currentNum==1 ){
moveElement('focus_change_list',-900,0,5);
classNormal()
focusBtnList[2].className='current'
}
if (currentNum==2 ){
moveElement('focus_change_list',-1350,0,5);
classNormal()
focusBtnList[3].className='current'
}
if (currentNum==3 ){
moveElement('focus_change_list',0,0,5);
classNormal()
focusBtnList[0].className='current'
}
}
window.onload=function(){
focusChange();
}
</script>
</head>
<body>
<div id="focus_change">
<div id="focus_change_list" style="top:0; left:0;">
<ul>
<li><a href="http://www.jb51.net/"><img src="/images/m03.jpg" alt="" /></a></li>
<li><a href="http://www.jb51.net/"><img src="/images/m04.jpg" alt="" /></a></li>
<li><a href="http://www.jb51.net/"><img src="/images/m09.jpg" alt="" /></a></li>
<li><a href="http://www.jb51.net/"><img src="/images/m10.jpg" alt="" /></a></li>
</ul>
</div>
<div class="focus_change_opacity"></div>
<div id="focus_change_btn">
<ul>
<li class="current"><a href="#"><img src="/images/s3.jpg" alt="" /></a></li>
<li><a href="#"><img src="/images/s4.jpg" alt="" /></a></li>
<li><a href="#"><img src="/images/s9.jpg" alt="" /></a></li>
<li><a href="#"><img src="/images/s10.jpg" alt="" /></a></li>
</ul>
</div>
</div><!--focus_change end-->
<div style="height:20px; background:#EEE;"></div>
</body>
</html>
希望本文所述對大家的javascript程序設計有所幫助。