javascript 轮播 缩略图 怎么实现

Question

如题所述

Answer 1

javascript 轮播 缩略图 实现

<script>
window.onload = function () {
var bottom = $('bottom'),title = $('title'),
img = $('img'),left = $('left'),right = $('right');
var aSpan = bottom.getElementsByTagName('span');
var aDiv = bottom.getElementsByTagName('div');
var arr = ['图片一','图片二','图片三', '图片四'];
var num = 0;
// 初始化
picTab();

// 点击下一张
right.onclick = function () {
if (num === aDiv.length - 1) num = -1;
num++;
picTab();
}

// 点击上一张
left.onclick = function () {
if (num === 0) num = aDiv.length;
num--;
picTab();
}

function picTab() {
title.innerHTML = arr[num];
img.src = 'img/' + (num + 1) + '.png';
for ( var i = 0; i < aSpan.length; i++ ) {
aSpan[i].className = '';
}
aSpan[num].className = 'active';
}
// 鼠标移入移出显示缩略图
for ( var i = 0; i < aSpan.length; i++ ) {
aSpan[i].index = i;
aSpan[i].onmouseover = function () {
aDiv[this.index].style.display = 'block';
}
aSpan[i].onmouseout = function () {
aDiv[this.index].style.display = 'none';
}
aSpan[i].onclick = function () {
num = this.index;
picTab();
}
}
function $(id) { return document.getElementById(id);}
}
</script>