HTML+CSS+JS实现轮播效果

1.lunbo.html代码：

    
    
    
    




    

        
        
        
        
        
    

        
        
        
    
    <
    >

2.CSS/lunbo.css代码：

body {
    margin: 0px;
    padding: 0px;
    width: 1350px;
    height: 618px;
}

a {
    text-decoration: none;
}

#container {
    width: 1350px;
    height: 618px;
    overflow: hidden;
    position: relative;
    border-top: 1px solid #ac6a0a;
}

#list {
    width: 6750px;
    height: 618px;
    position: absolute;
    z-index: 1;
}

#list img {
    float: left;
    width: 1350px;
    height: 618px;
}

#buttons {
    position: absolute;
    height: 20px;
    width: 60px;
    z-index: 2;
    bottom: 20px;
    left: 50%;
}

#buttons span {
    cursor: pointer;
    float: left;
    border: 1px solid #ad6a0a;
    width: 10px;
    height: 10px;
    -webkit-border-radius: 50%;
    -moz-border-radius: 50%;
    border-radius: 50%;
    margin-right: 5px;
}

#buttons .on {
    background: orangered;
}

.arrow {
    cursor: pointer;
    display: none;
    line-height: 100px;
    text-align: center;
    width: 40px;
    height: 40px;
    position: absolute;
    z-index: 2;
    top: 180px;
    background-color: RGBA(0, 0, 0, 0);
    color: #fff;
}

.arrow:hover {
    background-color: RGBA(0, 0, 0, 0);
}

#container:hover .arrow {
    display: block;
}

#prev {
    left: 10px;
    color: #ffffff;
}

#next {
    right: 10px;
    color: #ffffff;
}

3.JS/lunbo.js代码：

window.onload = function () {
    var container = document.getElementById('container');
    var list = document.getElementById('list');
    var buttons = document.getElementById('buttons').getElementsByTagName('span');
    var prev = document.getElementById('prev');
    var next = document.getElementById('next');
    var index = 1;
    var len = 3;
    var animated = false;
    var interval = 3000;
    var timer;
    var size = 1350;

    function animate(offset) {
        if (offset == 0) {
            return;
        }
        animated = true;
        var time = 300;
        var inteval = 10;
        var speed = offset / (time / inteval);
        console.log("speed:" + speed);
        var left = parseInt(list.style.left) + offset;

        var go = function () {
            if ((speed > 0 && parseInt(list.style.left) < left) || (speed < 0 && parseInt(list.style.left) > left)) {
                list.style.left = parseInt(list.style.left) + speed + 'px';
                console.log(list.style.left);
                setTimeout(go, inteval);
            } else {
                list.style.left = left + 'px';
                if (left > -200) {
                    list.style.left = -size * len + 'px';
                }
                if (left < ( -size * len)) {
                    list.style.left = '-' + size + 'px';
                }
                animated = false;
                console.log("left:" + list.style.left);
            }
        }
        go();
    }

    function showButton() {
        for (var i = 0; i < buttons.length; i++) {
            if (buttons[i].className == 'on') {
                buttons[i].className = '';
                break;
            }
        }
        buttons[index - 1].className = 'on';
    }

    function play() {
        timer = setTimeout(function () {
                next.onclick();
                play();
            },
            interval);
    }

    function stop() {
        clearTimeout(timer);
    }

    next.onclick = function () {
        if (animated) {
            return;
        }
        if (index == len) {
            index = 1;
        } else {
            index += 1;
        }
        animate(-size);
        showButton();
    }
    prev.onclick = function () {
        if (animated) {
            return;
        }
        if (index == 1) {
            index = len;
        } else {
            index -= 1;
        }
        animate(size);
        showButton();
    }
    for (var i = 0; i < buttons.length; i++) {
        buttons[i].onclick = function () {
            if (animated) {
                return;
            }
            if (this.className == 'on') {
                return;
            }
            var myIndex = parseInt(this.getAttribute('index'));
            var offset = -size * (myIndex - index);

            animate(offset);
            index = myIndex;
            showButton();
        }
    }
    container.onmouseover = stop;
    container.onmouseout = play;
    play();
};