轮播图

HTML：

css：

*{
    margin:0;
    padding:0;
  }
  a{
    text-decoration: none;
  }
  .container {
    position: relative;
    width: 600px;
    height: 400px;
    margin:100px auto 0 auto;
    box-shadow: 0 0 5px rgb(180, 182, 180);
    overflow: hidden;
  }
  .container .wrap {
    position: absolute;
    width: 4200px;
    height: 400px;
    z-index: 1;
  }
  .container .wrap img {
    float: left;
    width: 600px;
    height: 400px;
  }
  .container .buttons {
    position: absolute;
    right: 5px;
    bottom:30px;
    width: 120px;
    height: 10px;
    z-index: 2;
  }
  .container .buttons span {
    margin-left: 5px;
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: rgb(211, 212, 211);
    text-align: center;
    color:white;
    cursor: pointer;
  }
  .container .buttons span.on{
    background-color: rgb(151, 150, 150);
  }
  .container .arrow {
    position: absolute;
    top: 40%;
    color: rgb(179, 182, 179);
    padding:0px 15px;
    border-radius: 50%;
    font-size: 50px;
    z-index: 2;
    display: none;
  }
  .container .arrow_left {
    left: 10px;
  }
  .container .arrow_right {
    right: 10px;
  }
  .container:hover .arrow {
    display: block;
  }
  .container .arrow:hover {
    background-color: rgba(0,0,0,0.2);
  }

js:

// 下一页
function next_pic(wrap) {
    index++;
    if (index > 4) {
        index = 0;
    }
    showCurrentDot(wrap);
    var newLeft;
    if (wrap.style.left === "-3600px") {
        newLeft = -1200;
    } else {
        newLeft = parseInt(wrap.style.left) - 600;
    }
    wrap.style.left = newLeft + "px";
}
// 上一页
function prev_pic(wrap) {
    index--;
    if (index < 0) {
        index = 4;
    }
    showCurrentDot(wrap);
    var newLeft;
    if (wrap.style.left === "0px") {
        newLeft = -2400;
    } else {
        newLeft = parseInt(wrap.style.left) + 600;
    }
    wrap.style.left = newLeft + "px";
}
// 定时器 --- 自动播放
let timer = null;
function autoPlay(wrap) {
    timer = setInterval(function () {
        next_pic(wrap);
    }, 2000);
}

// 圆点导航
let index = 0;
let dots = document.getElementsByTagName("span");
// 显示当前是第几张图片
function showCurrentDot(wrap) {
    for (var i = 0, len = dots.length; i < len; i++) {
        dots[i].className = "";
    }
    dots[index].className = "on";
}
//最开始和最后的照片修整
for (var i = 0, len = dots.length; i < len; i++) {
    (function (i) {
        let wrap = document.querySelector(".wrap");
        dots[i].onclick = function () {
            var dis = index - i;
            if (index == 4 && parseInt(wrap.style.left) !== -3000) {
                dis = dis - 5;
            }
            //和使用prev和next相同，在最开始的照片5和最终的照片1在使用时会出现问题，导致符号和位数的出错，做相应地处理即可
            if (index == 0 && parseInt(wrap.style.left) !== -600) {
                dis = 5 + dis;
            }
            wrap.style.left = (parseInt(wrap.style.left) + dis * 600) + "px";
            index = i;
            showCurrentDot(wrap);

        }
    })(i);
}
function init() {
    var wrap = document.querySelector(".wrap");
    var next = document.querySelector(".arrow_right");
    var prev = document.querySelector(".arrow_left");
    // 当鼠标点击上下箭头
    next.onclick = function () {
        next_pic(wrap);
    }
    prev.onclick = function () {
        prev_pic(wrap);
    }
    //启动定时器
    autoPlay(wrap);
    // 鼠标滑过 取消自动播放
    var container = document.querySelector(".container");
    container.onmouseenter = function () {
        clearInterval(timer);
    }
    container.onmouseleave = function () {
        autoPlay(wrap);
    }
}
window.addEventListener('load', init, false);