前端学习（1635）：前端系列实战课程之自动播放选项卡

本文链接：https://blog.csdn.net/weixin_43392489/article/details/106959173

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #box .on {
            background-color: red;
        }
        
        #box div {
            width: 100px;
            height: 100px;
            background: 1px solid red;
            display: none;
        }
    </style>
    <script>
        window.onload = function() {
            var oBox = document.getElementById('box');
            var aBtn = oBox.getElementsByTagName('input');
            var oDiv = oBox.getElementsByTagName('div');
            var oPrev = document.getElementById('prev');
            var oNext = document.getElementById('next');

            var iNow = 0;
            var timer = null;

            function tab() {
                for (var i = 0; i < aBtn.length; i++) {
                    aBtn[i].className = '';
                    oDiv[i].style.display = 'none';
                }
                aBtn[iNow].className = 'on';
                oDiv[iNow].style.display = 'block'
            }
            for (var i = 0; i < aBtn.length; i++) {
                aBtn[i].index = i;
                aBtn[i].onclick = function() {
                    iNow = this.index;
                    /* for (var i = 0; i < aBtn.length; i++) {
                        aBtn[i].className = '';
                        oDiv[i].style.display = 'none';
                    } */
                    /* aBtn[iNow].className = 'on';
                    oDiv[this.index].style.display = 'block' */
                    tab();
                }
            }
            //下一个播放
            function fnNext() {
                tab();
                iNow++;
                console.log(iNow)
                if (iNow == aBtn.length) {
                    iNow = 0;
                }
            }
            oNext.onclick = fnNext;


            //上一个播放
            oPrev.onclick = function() {
                /* for (var i = 0; i < aBtn.length; i++) {
                    aBtn[i].className = '';
                    oDiv[i].style.display = 'none';
                }
                aBtn[iNow].className = 'on';
                oDiv[iNow].style.display = 'block' */
                tab();
                iNow--;
                console.log(iNow)
                if (iNow == -1) {
                    iNow = aBtn.length - 1;
                }

            }
            timer = setInterval(function() {
                fnNext();
            }, 1000);
            oBox.onmouseover = function() {
                clearInterval(timer);
            }
            oBox.onmouseover = function() {
                clearInterval(timer);
                timer = setInterval(function() {
                    fnNext();
                }, 1000);
            }
        }
    </script>
</head>

<body>
    <div id="box">
        <a href="javascript:;" id="prev">左边</a>
        <input type="button" value="aaa" class="on">
        <input type="button" value="bbb">
        <input type="button" value="ccc">
        <a href="javascript:;" id="next">右边</a>
        <div>aaa</div>
        <div>bbb</div>
        <div>ccc</div>
    </div>
</body>

</html>

运行结果