demo-在线查看效果

css

        * {
            padding: 0;
            margin: 0;
            list-style: none;
            border: 0;
        }

        .all {
            width: 500px;
            height: 200px;
            padding: 7px;
            border: 1px solid #ccc;
            margin: 100px auto;
            position: relative;
        }

        .screen {
            width: 500px;
            height: 200px;
            overflow: hidden;
            position: relative;
        }

        .screen li {
            width: 500px;
            height: 200px;
            overflow: hidden;
            float: left;
        }

        .screen ul {
            position: absolute;
            left: 0;
            top: 0px;
            width: 3000px;
        }

        .all ol {
            position: absolute;
            right: 10px;
            bottom: 10px;
            line-height: 20px;
            text-align: center;
        }

        .all ol li {
            float: left;
            width: 20px;
            height: 20px;
            background: #fff;
            border: 1px solid #ccc;
            margin-left: 10px;
            cursor: pointer;
        }

        .all ol li.current {
            background: yellow;
        }

        #arr {
            display: none;
        }

        #arr span {
            width: 40px;
            height: 40px;
            position: absolute;
            left: 5px;
            top: 50%;
            margin-top: -20px;
            background: #000;
            cursor: pointer;
            line-height: 40px;
            text-align: center;
            font-weight: bold;
            font-family: '黑体';
            font-size: 30px;
            color: #fff;
            opacity: 0.3;
            border: 1px solid #fff;
        }

        #arr #right {
            right: 5px;
            left: auto;
        }
        

html

    
    <div class="all" id='box'>
        <div class="screen">
            <ul>
                <li><img src="images/1.jpg" width="500" height="200"/></li>
                <li><img src="images/2.jpg" width="500" height="200"/></li>
                <li><img src="images/3.jpg" width="500" height="200"/></li>
                <li><img src="images/4.jpg" width="500" height="200"/></li>
                <li><img src="images/5.jpg" width="500" height="200"/></li>
            </ul>
            <ol></ol>
        </div>
        <div id="arr"><span id="left">&lt;</span><span id="right">&gt;</span></div>
    </div>

javaScript

    var timer = null;
    //找人
    var box = document.getElementById("box");
    var screen = box.children[0];
    var ul = screen.children[0];
    var ulLis = ul.children;
    var ol = screen.children[1];
    var arr = document.getElementById("arr");
    var left = document.getElementById("left");
    var right = document.getElementById("right");
    var imgWidth = screen.offsetWidth;


    //动态生成结构
    //生成ol中的按钮
    for (var i = 0; i < ulLis.length; i++) {
        var li = document.createElement("li");
        li.innerHTML = i + 1;
        ol.appendChild(li);
    }
    var olLis = ol.children;
    olLis[0].className = "current";
    //克隆第一张图
    var firstImg = ulLis[0].cloneNode(true);
    ul.appendChild(firstImg);

    //鼠标经过按钮  按钮排他 移动ul到相应位置
    for (var j = 0; j < olLis.length; j++) {
        olLis[j].index = j;
        olLis[j].onmouseover = function () {
            //干掉所有人
            for (var i = 0; i < olLis.length; i++) {
                olLis[i].className = "";
            }
            //留下我自己
            this.className = "current";
            //移动ul
            //目标和 当前按钮的索引有关 和图片宽度有关 而且是负数
            var target = -this.index * imgWidth;
            animate(ul, target);
            //把记录当前显示的图片的索引的pic统一成当前按钮的索引
            //把记录当前亮起的按钮的索引的square统一成当前按钮的索引
            pic = square = this.index;

        };
    }

    //点击箭头
    box.onmouseover = function () {
        arr.style.display = "block";
        clearInterval(timer);
    };
    box.onmouseout = function () {
        arr.style.display = "none";
        timer = setInterval(playNext, 1000);
    };
    var pic = 0;//记录当前显示的图片的索引
    var square = 0;//记录当前亮起的按钮的索引

    //点击右箭头 移动ul到相应位置
    right.onclick = function () {
        //如果是最后一张 就应该 瞬间跳回开始 然后让ul从真的第一张渐渐地移动到第二张
        if (pic === ulLis.length - 1) {//最后一张图片的索引
            ul.style.left = 0;
            pic = 0;//pic也要归零
        }
        pic++;//计算接下来要显示的图片的索引
        //目标 和pic有关 和图片宽度有关 而且是负数
        var target = -pic * imgWidth;
        animate(ul, target);

        //按钮也要跟着跑
        if (square < olLis.length - 1) {
            square++;//计算出接下来要亮起的按钮的索引
        } else {
            square = 0;
        }

        //干掉所有人
        for (var i = 0; i < olLis.length; i++) {
            olLis[i].className = "";
        }
        //留下对应的
        olLis[square].className = "current";

    };
    left.onclick = function () {
        //如果是第一张 就应该 瞬间跳回最后 然后让ul从假的第一张渐渐地移动到真的最后一张
        if (pic === 0) {
            ul.style.left = -(ulLis.length - 1) * imgWidth + "px";
            pic = ulLis.length - 1;//pic要变到最后
        }
        pic--;//计算接下来要显示的图片的索引
        //目标 和pic有关 和图片宽度有关 而且是负数
        var target = -pic * imgWidth;
        animate(ul, target);

        //按钮也要跟着跑
        if (square > 0) {
            square--;//计算出接下来要亮起的按钮的索引
        } else {
            square = olLis.length - 1;
        }

        //干掉所有人
        for (var i = 0; i < olLis.length; i++) {
            olLis[i].className = "";
        }
        //留下对应的
        olLis[square].className = "current";
    };

    //添加自动滚动
    timer = setInterval(playNext, 1000);
    function playNext() {
        right.onclick();
    }

    function animate(obj, target) {
        clearInterval(obj.timer);
        obj.timer = setInterval(function () {
            var leader = obj.offsetLeft;
            var step = 30;
            step = leader < target ? step : -step;
            if (Math.abs(target - leader) >= Math.abs(step)) {
                leader = leader + step;
                obj.style.left = leader + "px";
            } else {
                obj.style.left = target + "px";
                clearInterval(obj.timer);
            }
        }, 15);
    }