本文目录一览：
怎样用javascript实现图片定时切换
思路：使用javascript定时器函数setTimeout()每隔一定的毫秒间隔数执行动作，在执行的动作中循环替换图片的src属性。树立演示如下：
1、HTML结构
img src="1.png" id="test"
2、javascript代码
function change(n){
if(n5) n=1; // 一共5张图片，所以循环替换
document.getElementById("test").setAttribute("src", n+".png");
n++;
setTimeout("change("+n+")",1000);
}
window.onload = function(){
setTimeout("change(1)", 1000);
}
3、效果演示
JavaScript 的网页图片切换代码
!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ""
html xmlns=""
head
meta http-equiv="Content-Type" content="text/html; charset=gb2312"
title网页特效 首页图片切换/title
style type="text/css"
/* Reset style */
* { margin:0; padding:0; word-break:break-all; }
body {
background:#fff;
color:#000000;
font:12px/1.6em Helvetica, Arial, sans-serif;
margin-left: 0px;
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
}
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:650px; height:245px; margin:0px; border:1px solid #DEDEDE; background:#F8F8F8; }
#ifocus_pic { display:inline; position:relative; float:left; width:540px; height:225px; overflow:hidden; margin:10px 0 0 10px; }
#ifocus_piclist { position:absolute; }
#ifocus_piclist li { width:550px; height:225px; overflow:hidden; }
#ifocus_piclist img { width:550px; 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(img/ifocus_btn_bg.gif) no-repeat; opacity:1; -moz-opacity:1; filter:alpha(opacity=100); }
#ifocus_opdiv { position:absolute; left:0; bottom:0; width:545px; 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; iiFocusBtns.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 = $('ifocus_btn').getElementsByTagName('li');
var listLength = iFocusBtns.length;
iFocusBtns[0].onmouseover = function() {
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
if (listLength=2) {
iFocusBtns[1].onmouseover = function() {
moveElement('ifocus_piclist',0,-225,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',1);
}
}
if (listLength=3) {
iFocusBtns[2].onmouseover = function() {
moveElement('ifocus_piclist',0,-450,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',2);
}
}
if (listLength=4) {
iFocusBtns[3].onmouseover = function() {
moveElement('ifocus_piclist',0,-675,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',3);
}
}
}
setInterval('autoiFocus()',3500);
var atuokey = false;
function autoiFocus() {
if(!$('ifocus')) return false;
if(atuokey) return false;
var focusBtnList = $('ifocus_btn').getElementsByTagName('li');
var listLength = focusBtnList.length;
for(var i=0; ilistLength; i++) {
if (focusBtnList[i].className == 'current') var currentNum = i;
}
if (currentNum==0listLength!=1 ){
moveElement('ifocus_piclist',0,-225,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',1);
}
if (currentNum==1listLength!=2 ){
moveElement('ifocus_piclist',0,-450,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',2);
}
if (currentNum==2listLength!=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==1listLength==2 ){
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
if (currentNum==2listLength==3 ){
moveElement('ifocus_piclist',0,0,5);
classNormal('ifocus_btn','ifocus_tx');
classCurrent('ifocus_btn','ifocus_tx',0);
}
}
addLoadEvent(iFocusChange);
/script
/head
body
br /
div align="center"
div id="ifocus"
div id="ifocus_pic"
div id="ifocus_piclist" style="left:0; top:0;"
ul
lia href="#" target="_blank"img src="/edu/img/js/200909/1.jpg" alt="武林三国" border="0" //a/li
lia href="#" target="_blank"img src="/edu/img/js/200909/2.jpg" alt="武林英雄" border="0" //a/li
lia href="#" target="_blank"img src="/edu/img/js/200909/3.jpg" alt="商业大亨" border="0" //a/li
lia href="#" target="_blank"img src="/edu/img/js/200909/4.jpg" alt="帝国远征" border="0" //a/li
/ul
/div
div id="ifocus_opdiv"/div
div id="ifocus_tx"
ul
li class="current"2008年度排名第一的网页游戏/li
li class="normal"2009年最新的网页游戏 /li
li class="normal"商业大亨，挑战亿万富翁/li
li class="normal"一款2009年不得不玩的帝国远征/li
/ul
/div
/div
div id="ifocus_btn"
ul
li class="current"img src="/edu/img/js/200909/s1.jpg" alt="" //li
li class="normal"img src="/edu/img/js/200909/s2.jpg" alt="" //li
li class="normal"img src="/edu/img/js/200909/s3.jpg" alt="" //li
li class="normal"img src="/edu/img/js/200909/s4.jpg" alt="" //li
/ul
/div
/div
/div
/body
/html
自己改图片链接和大小~~
图片自动切换的JS代码
试试这个图片切换
有12345数字一起切换
鼠标点一下数字会变换到另一张图片，不点就会自动换
里面有教程和源码
