Javascript制作焦点图片轮换效果_Javascript教程_H5之家

此个效果原本是一个很酷的flash做的，效果也十分的炫，那渐变和鼠标移过时的按钮跟踪十分喜欢,应该很多人都看到过这效果。同时我也想拥有一个JS版的，此次焦点图片轮换效果占命名为iFocus，还有很多细节方面没达到flash那种程度，但基本需求可以满足。

主要效果：
1.大图，小图，及对应的标题，自动每5秒活动焦点变化一次
2.当鼠标移到此效果上面时，停止每5秒自动焦点变化
3.当鼠标移动到四个小图上时，焦点变换到相对应的大图及标题
4.当传的内容过少只存在1,2,3个列表，循环时不影响效果自动轮换活动

扩展修改：
1.为适应网页布局时，在修改大小时，大图，小图对应的img需要修改
2.大图是利用top值滚动，相对应的值top值在js里也需要修改
3.然后对滚动时间间隔可在setInterval(’autoiFocus()’,5000)中对5000进行修改,5000=5秒；

详细代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "">
<html xmlns="">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>佐佐制造byzuo.cn---焦点图片第三季</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:#0287CA; text-decoration:none; }
a:hover { text-decoration:underline; }
ul, li { list-style:none; }
fieldset, img { border:none; }
legend { display:none; }
em, strong, cite, th { font-style:normal; font-weight:normal; }
input, textarea, select, button { font:12px Helvetica, Arial, sans-serif; }
table { border-collapse:collapse; }
html { overflow:-moz-scrollbars-vertical; } /*Always show Firefox scrollbar*/
/* iFocus style */
#ifocus { width:525px; height:245px; margin:20px; border:1px solid #DEDEDE; background:#F8F8F8; }
#ifocus_pic { display:inline; position:relative; float:left; width:410px; height:225px; overflow:hidden; margin:10px 0 0 10px; }
  #ifocus_piclist { position:absolute; }
  #ifocus_piclist li { width:410px; height:225px; overflow:hidden; }
  #ifocus_piclist img { width:410px; height:225px; }
#ifocus_btn { display:inline; float:right; width:91px; margin:9px 9px 0 0; }
  #ifocus_btn li { width:91px; height:57px; cursor:pointer; opacity:0.5; -moz-opacity:0.5; filter:alpha(opacity=50); }
  #ifocus_btn img { width:75px; height:45px; margin:7px 0 0 11px; }
  #ifocus_btn .current { background: url() no-repeat; opacity:1; -moz-opacity:1; filter:alpha(opacity=100); }
#ifocus_opdiv { position:absolute; left:0; bottom:0; width:410px; height:35px; background:#000; opacity:0.5; -moz-opacity:0.5; filter:alpha(opacity=50); }
#ifocus_tx { position:absolute; left:8px; bottom:8px; color:#FFF; }
  #ifocus_tx .normal { display:none; }
</style>
<script type="text/javascript">
function $(id) { return document.getElementById(id); }
function addLoadEvent(func){
var oldonload = window.onload;
if (typeof window.onload != 'function') {
  window.onload = func;
} else {
  window.onload = function(){
   oldonload();
   func();
  }
}
}
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(iFocusBtnID,iFocusTxID){
var iFocusBtns= $(iFocusBtnID).getElementsByTagName('li');
var iFocusTxs = $(iFocusTxID).getElementsByTagName('li');
for(var i=0; i<iFocusBtns.length; i++) {
  iFocusBtns[i].className='normal';
  iFocusTxs[i].className='normal';
}
}
function classCurrent(iFocusBtnID,iFocusTxID,n){
var iFocusBtns= $(iFocusBtnID).getElementsByTagName('li');
var iFocusTxs = $(iFocusTxID).getElementsByTagName('li');
iFocusBtns[n].className='current';
iFocusTxs[n].className='current';
}
function iFocusChange() {
if(!$('ifocus')) return false;
$('ifocus').onmouseover = function(){atuokey = true};
$('ifocus').onmouseout = function(){atuokey = false};
var iFocusBtns = $('ifocus_btn').getElementsByTagName('li');
var listLength = iFocusBtns.length;
iFocusBtns[0].onmouseover = function() {
  moveElement('ifocus_piclist',0,0,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',0);
}
if (listLength>=2) {
  iFocusBtns[1].onmouseover = function() {
   moveElement('ifocus_piclist',0,-225,5);
   classNormal('ifocus_btn','ifocus_tx');
   classCurrent('ifocus_btn','ifocus_tx',1);
  }
}
if (listLength>=3) {
  iFocusBtns[2].onmouseover = function() {
   moveElement('ifocus_piclist',0,-450,5);
   classNormal('ifocus_btn','ifocus_tx');
   classCurrent('ifocus_btn','ifocus_tx',2);
  }
}
if (listLength>=4) {
  iFocusBtns[3].onmouseover = function() {
   moveElement('ifocus_piclist',0,-675,5);
   classNormal('ifocus_btn','ifocus_tx');
   classCurrent('ifocus_btn','ifocus_tx',3);
  }
}
}
setInterval('autoiFocus()',5000);
var atuokey = false;
function autoiFocus() {
if(!$('ifocus')) return false;
if(atuokey) return false;
var focusBtnList = $('ifocus_btn').getElementsByTagName('li');
var listLength = focusBtnList.length;
for(var i=0; i<listLength; i++) {
  if (focusBtnList[i].className == 'current') var currentNum = i;
}
if (currentNum==0&&listLength!=1 ){
  moveElement('ifocus_piclist',0,-225,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',1);
}
if (currentNum==1&&listLength!=2 ){
  moveElement('ifocus_piclist',0,-450,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',2);
}
if (currentNum==2&&listLength!=3 ){
  moveElement('ifocus_piclist',0,-675,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',3);
}
if (currentNum==3 ){
  moveElement('ifocus_piclist',0,0,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',0);
}
if (currentNum==1&&listLength==2 ){
  moveElement('ifocus_piclist',0,0,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',0);
}
if (currentNum==2&&listLength==3 ){
  moveElement('ifocus_piclist',0,0,5);
  classNormal('ifocus_btn','ifocus_tx');
  classCurrent('ifocus_btn','ifocus_tx',0);
}
}
addLoadEvent(iFocusChange);
</script>
</head>
<body>
<div id="ifocus">
<div id="ifocus_pic">
  <div id="ifocus_piclist" style="left:0; top:0;">
   <ul>
    <li><a href="#"><img src="" alt="" /></a></li>
    <li><a href="#"><img src="" alt="" /></a></li>
    <li><a href="#"><img src="" alt="" /></a></li>
    <li><a href="#"><img src="" alt="" /></a></li>
   </ul>
  </div>
  <div id="ifocus_opdiv"></div>
  <div id="ifocus_tx">
   <ul>
    <li class="current">火箭85-78马刺姚明依旧像新秀a1</li>
    <li class="normal">阿德尔曼：姚明进攻太犹豫火箭还有很长路要走b2</li>
    <li class="normal">阿联脚伤未出场卡特意外受伤网队加时险胜热队c3</li>
    <li class="normal">帕杜惊讶能留住郑智英媒称查尔顿升超要靠d4</li>
   </ul>
  </div>
</div>
<div id="ifocus_btn">
  <ul>
   <li class="current"><img src="" alt="" /></li>
   <li class="normal"><img src="" alt="" /></li>
   <li class="normal"><img src="" alt="" /></li>
   <li class="normal"><img src="" alt="" /></li>
  </ul>
</div>
</div>
</body>
</html>