本文实例介绍了js实现图片轮播相册，具有过渡渐变效果，分享给大家供大家参考，具体内容如下
思路很简单，用2个属性保存当前图片和上一张图片，用2个定时器分别控制透明度和当前过渡的图片。
<HTML>
<HEAD>
<TITLE></TITLE>
</HEAD>
<style>
#cnt{width:100%;height:80%;}
.ctrl{text-align:center;border:1px solid gray;font-size:12px;cursor:pointer;}
</style>
<script defer='defer'>
<!--
var curOpac = 0;
var filterTimer;
var isIE = /internet explorer/i.test(window.navigator.appName);
function MyScroll(cnt, control){
this.data = []; // 存放图片路径
this.interval = 3000; // 过渡一次的间隔时间(过渡时间+图片显示时间)
this.timer; // 定时器：控制当前显示的图片
this.container = cnt;
this.curFrame = 0;
this.oldFrame = 0;
this.controls = control; // 按钮集合
Global = this; // 获取对象的指针
this.run = function(){
this.timer = window.setInterval("Global.showFrame()", this.interval);
}
// 按钮的处理程序
this.go = function(i){
curOpac = 0; // 透明度归0
this.curFrame = i; // 当前要过渡的图片
this.stop(); // 清空计时器
this.showFrame(); // 当前图片过渡
this.run(); // 循环播放
}
this.stop = function(){
window.clearInterval(this.timer);
window.clearInterval(filterTimer);
}
this.showFrame = function(){
// 设置当前按钮样式
this.controls[this.oldFrame].style.backgroundColor = "white";
this.controls[this.curFrame].style.backgroundColor = "gray";
if(isIE) this.container.style.filter = "alpha(opacity=0)";
else this.container.style.cssText = "-moz-opacity:0";
this.container.innerHTML = this.data[this.curFrame];
filterTimer = window.setInterval("blend()", 100);
this.oldFrame = this.curFrame;
this.curFrame ++;
if(this.curFrame == this.data.length){
this.curFrame = 0;
}
}
}
// 增加透明度
function blend(){
curOpac+=10;
if(isIE) Global.container.style.filter='alpha(opacity=' + curOpac + ')';
else Global.container.style.cssText = "-moz-opacity:" + curOpac/100.0;
if(curOpac == 100){
curOpac = 0;
window.clearInterval(filterTimer);
}
}
//开始
function startIt(){
var imgArr = [];
// 创建4个图片对象保存图片路径
for(var i=0;i<4;i++){
imgArr[i] = new Image();
imgArr[i].src = "images/banner" + (i + 1) + ".jpg";
}
var controlArr = $("mainTb").getElementsByTagName("span");
for(var i=0;i<controlArr.length;i++){
controlArr[i].tag = i;
controlArr[i].onclick = function(){
myScroll.go(this.tag);
}
}
var myScroll = new MyScroll($("cnt"), controlArr);
myScroll.data.push("<img src='" + imgArr[0].src + "'>");
myScroll.data.push("<img src='" + imgArr[1].src + "'>");
myScroll.data.push("<img src='" + imgArr[2].src + "'>");
myScroll.data.push("<img src='" + imgArr[3].src + "'>");
myScroll.go(0);
}
window.onload = startIt;
function $(id){ return document.getElementById(id);}
//-->
</script>
<BODY>
<table width="300" height="100" id="mainTb">
<tr>
<th rowspan="4"><div id="cnt"> </div></td>
<td width="15"><span class="ctrl"> 1 </span></td>
</tr>
<tr>
<td><span class="ctrl"> 2 </span></td>
</tr>
<tr>
<td><span class="ctrl"> 3 </span></td>
</tr>
<tr>
<td><span class="ctrl"> 4 </span></td>
</tr>
</table>
</BODY>
</HTML>
以上就是本文的全部内容，希望对大家学习javascript程序设计有所帮助。