视图：
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style> p { margin: 0; } body { text-align: center; } #box { width: 400px; height: 400px; border: 10px solid #ccc; margin: 50px auto 0; position: relative; } a { width: 40px; height: 40px; background: #fff; filter: alpha(opacity: 80); opacity: 0.8; position: absolute; top: 160px; font-size: 18px; color: #000; text-align: center; line-height: 40px; text-decoration: none; } a:hover { filter: alpha(opacity: 30); opacity: 0.3; } #prev { left: 10px; } #next { right: 10px; } #p1 { width: 400px; height: 30px; line-height: 30px; text-align: center; background: #000; color: #fff; font-size: 14px; filter: alpha(opacity: 80); opacity: 0.8; position: absolute; bottom: 0; left: 0; } strong { width: 400px; height: 30px; line-height: 30px; text-align: center; background: #000; color: #fff; font-size: 14px; filter: alpha(opacity: 80); opacity: 0.8; position: absolute; top: 0; left: 0; } #img1 { width: 400px; height: 400px; } span { position: absolute; width: 400px; height: 30px; line-height: 30px; text-align: center; top: -50px; left: 0; font-family: '微软雅黑'; } </style> <script> window.onload = function() { var oPrev = document.getElementById('prev'); var oNext = document.getElementById('next'); var oP = document.getElementById('p1'); var oStrong = document.getElementById('strong1'); var oImg = document.getElementById('img1'); var aBtn = document.getElementsByTagName('input'); var arrUrl = ['img/1.jpg', 'img/2.jpg', 'img/3.jpg', 'img/4.jpg']; var arrText = ['文字一', '文字二', '文字三', '识文断字']; var num = 0; var onOff = true; aBtn[0].onclick = function() { onOff = true; document.getElementsByTagName('span')[0].innerHTML = '图片可从最后一张跳转到第一张循环切换'; }; aBtn[1].onclick = function() { onOff = false; document.getElementsByTagName('span')[0].innerHTML = '图片只能到最后一张或只能到第一张切换'; }; // 初始化 function fnTab() { oP.innerHTML = arrText[num]; oStrong.innerHTML = num + 1 + ' / ' + arrText.length; oImg.src = arrUrl[num]; } fnTab(); oPrev.onclick = function() { num--; if(num == -1) { if(onOff) { num = arrText.length - 1; } else { alert('这已经是第一张了，不能再往前了~~'); num = 0; } //num = arrText.length-1; } fnTab(); }; oNext.onclick = function() { num++; if(num == arrText.length) { if(onOff) { num = 0; } else { alert('已经到最后一张啦~'); num = arrText.length - 1; } } fnTab(); }; }; </script> </head> <body> <input type="button" value="循环切换" /> <input type="button" value="顺序切换" /> <div id="box"><span>图片可从最后一张跳转到第一张循环切换</span> <a id="prev" href="javascript:;"> <</a> <a id="next" href="javascript:;">></a> <p id="p1">图片文字加载中……</p> <strong id="strong1">图片数量计算中……</strong> <img id="img1" /> </div> </body> </html>