本文实例讲述了JS实现可切换图片的幻灯切换效果。分享给大家供大家参考，具体如下：
JS切换图片幻灯切换效果
body, div, ul, li { margin: 0; padding: 0; }
ul { list-style-type: none; }
body { background: #000; text-align: center; font: 12px/20px Arial; }
#box { position: relative; width: 322px; height: 172px; background: #fff; border-radius: 5px; border: 8px solid #fff; margin: 10px auto; }
#box .list { position: relative; width: 320px; height: 240px; overflow: hidden; border: 1px solid #ccc; }
#box .list li { position: absolute; top: 0; left: 0; width: 320px; height: 240px; opacity: 0; filter: alpha(opacity=0); }
#box .list li.current { opacity: 1; filter: alpha(opacity=100); }
#box .count { position: absolute; right: 0; bottom: 5px; }
#box .count li { color: #fff; float: left; width: 20px; height: 20px; cursor: pointer; margin-right: 5px; overflow: hidden; background: #F90; opacity: 0.7; filter: alpha(opacity=70); border-radius: 20px; }
#box .count li.current { color: #fff; opacity: 1; filter: alpha(opacity=100); font-weight: 700; background: #f60; }
#tmp { width: 100px; height: 100px; background: red; position: absolute; }
window.onload = function() {
var oBox = document.getElementById("box");
var aUl = document.getElementsByTagName("ul");
var aImg = aUl[0].getElementsByTagName("li");
var aNum = aUl[1].getElementsByTagName("li");
var timer = play = null;
var i = index = 0;
var bOrder = true;
//切换按钮
for(i = 0; i < aNum.length; i++) {
aNum[i].index = i;
aNum[i].onmouseover = function() {
show(this.index)
}
}
//鼠标划过关闭定时器
oBox.onmouseover = function() {
clearInterval(play)
};
//鼠标离开启动自动播放
oBox.onmouseout = function() {
autoPlay()
};
//自动播放函数
function autoPlay() {
play = setInterval(function() {
//判断播放顺序
bOrder ? index++ : index--;
//正序
index >= aImg.length && (index = aImg.length - 2, bOrder = false);
//倒序
index <= 0 && (index = 0, bOrder = true);
//调用函数
show(index)
}, 2000);
}
autoPlay();//应用
function show(a) {
index = a;
var alpha = 0;
for(i = 0; i < aNum.length; i++)aNum[i].className = "";
aNum[index].className = "current";
clearInterval(timer);
for(i = 0; i < aImg.length; i++) {
aImg[i].style.opacity = 0;
aImg[i].style.filter = "alpha(opacity=0)";
}
timer = setInterval(function() {
alpha += 2;
alpha > 100 && (alpha = 100);
aImg[index].style.opacity = alpha / 100;
aImg[index].style.filter = "alpha(opacity = " + alpha + ")";
alpha == 100 && clearInterval(timer)
}, 20);
}
};
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希望本文所述对大家JavaScript程序设计有所帮助。
