原生js实现网易轮播图

来源：互联网发布：美军战斗力知乎编辑：程序博客网时间：2024/05/16 02:43

    前端基本功-网页特效5

一、实现效果图
这里写图片描述
二、分析布局
主盒子里分上下两个小盒子（1和2）。
包含图片的盒子占两张图片的宽（3），处于上盒子中，当前图片在上盒子（1）中，其它图片在盒子（3）的右侧等待播放。
下边的盒子（2）包括了六个小方块及定位在主盒子上的两个箭头。
三、html部分

<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <title>wangyi</title>    <link type="text/css" rel="stylesheet" href="css/guide.css"/>    <script type="text/javascript" src="../animate.js"></script>    <script type="text/javascript" src="js/main.js"></script></head><body>    <div class="w-slider">        <div class="slider">            <div class="slider-main" id="slider_main_block">                <div class="slider-main-img"><a href="#"><img src="images/1.jpg"/></a></div>                <div class="slider-main-img"><a href="#"><img src="images/2.jpg"/></a></div>                <div class="slider-main-img"><a href="#"><img src="images/3.jpg"/></a></div>                <div class="slider-main-img"><a href="#"><img src="images/4.jpg"/></a></div>                <div class="slider-main-img"><a href="#"><img src="images/5.jpg"/></a></div>                <div class="slider-main-img"><a href="#"><img src="images/6.jpg"/></a></div>            </div>        </div>        <div class="slider-ctrl" id="slider_ctrl">            <span class="slider-ctrl-pre"></span>            <span class="slider-ctrl-next"></span>        </div>    </div></body></html>

四、CSS部分

* {    margin: 0;    padding: 0;}.w-slider {    width:310px;    height:265px;    margin:100px auto;    overflow: hidden;    position: relative;}.slider {    width:310px;    height:220px;}.slider-main {    width:620px;    height:220px;}.slider-main-img{    width:310px;    height:220px;    position:absolute;    top:0;    left:0;}.slider-main-img img{    vertical-align: top;}.slider-ctrl {    width:310px;    height:45px;    text-align:center;}.slider-ctrl span {    cursor: pointer;}.slider-ctrl-con {    display:inline-block;    width:24px;    height:20px;    margin-right:8px;    text-indent: -20em;    overflow:hidden;    background:url(../images/icon.png)-24px -782px no-repeat;}.slider-ctrl .current {    background:url(../images/icon.png)-24px -762px no-repeat;}.slider-ctrl-pre,.slider-ctrl-next {    width:27px;    height:38px;    position:absolute;    top:50%;    margin-top:-36px;    opacity:0.7;    filter:alpha(opacity=50);}.slider-ctrl-pre {    background:url(../images/icon.png)6px 1px no-repeat;    left:0;}.slider-ctrl-next {    background:url(../images/icon.png)-9px -44px no-repeat;    right:0;}

五、JS部

/** * Created by 15623544233 on 2016/10/17. */window.onload=function () {    //imgs的DOM对象    var slider_main_block =$("slider_main_block");    var sliderImgs =slider_main_block.children;        //最外层的slider大盒子    var sider_box =slider_main_block.parentNode.parentNode;    //slider-ctrl的DOM对象    var slider_ctrl = $("slider_ctrl");    var sliderCtrls =slider_ctrl.children;    //动态添加Ctrl    for(var i=0;i<sliderImgs.length;i++){       var spans = document.createElement("span");        spans.className="slider-ctrl-con"; //span中的数字为当前的索引，后面有重要作用        spans.innerHTML =sliderImgs.length-i;        slider_ctrl.insertBefore(spans,sliderCtrls[1]);    }    sliderCtrls[1].setAttribute("class","current slider-ctrl-con");    //imgW ---图片宽    var imgW = sliderImgs[0].clientWidth;    //让除第一张图以外的所有图右移    for(var i=1;i<sliderImgs.length;i++){        sliderImgs[i].style.left=imgW+"px";    }//至关重要的标志位，currentId 当前出现的盒子                 var currentId = 0;    for(var key in sliderCtrls){        sliderCtrls[key].onclick =function () {            //左箭头点击的运动动画                if(this.className=="slider-ctrl-pre"){                //与左移动参数相反                animate(sliderImgs[currentId],{left:imgW});                --currentId<0?currentId=sliderImgs.length-1:currentId;                sliderImgs[currentId].style.left=-imgW+"px";                animate(sliderImgs[currentId],{left:0});              //右箭头的运动动画，与自动轮播的运动动画一致            }else if(this.className=="slider-ctrl-next"){                autoPlay();            }else{                //得到当前要点击的图片索引号                var that = this.innerHTML-1;                if(that>currentId){                    //像点击右侧按钮一样播放                    animate(sliderImgs[currentId],{left:-imgW});                    sliderImgs[that].style.left=imgW+"px";                }else if(that<currentId){                    animate(sliderImgs[currentId],{left:imgW});                    sliderImgs[that].style.left=-imgW+"px";                }            /*当点击按钮后，当前图片currentId移动后，所点击的盒子成为当前的图片，使图片连续*/                currentId =that;                animate(sliderImgs[currentId],{left:0});            }            flashCurrent((currentId+1));        };    }    //小方块控制slider动画的函数    function flashCurrent(index) {        //console.log(index);        for(var i=1;i<sliderCtrls.length-1;i++){            sliderCtrls[i].setAttribute("class","slider-ctrl-con");        }        sliderCtrls[index].setAttribute("class","current slider-ctrl-con");    }    //添加定时器    var timer =null;    timer =setInterval(autoPlay,2000);    function autoPlay() {        animate(sliderImgs[currentId],{left:-imgW});        //当第6张左移走后，6>5,第0张回到框中        ++currentId>sliderImgs.length-1?currentId = 0:currentId;        //上一张图片左移后，下一张图片快速到右边        sliderImgs[currentId].style.left=imgW+"px";        //下张右侧图片左移        animate(sliderImgs[currentId],{left:0});    }    sider_box.onmouseover =function () {        clearInterval(timer);    }    sider_box.onmouseout=function () {        timer =setInterval(autoPlay,2000);    }};function $(id) {    return document.getElementById(id);} /*当前样式属性值的获取 */function curStyle(obj,attr){    if(obj.currentStyle){//IE浏览器      return obj.currentStyle[attr];    }else{  //标准浏览器      return window.getComputedStyle(obj,null)[attr];    }} /*封装的运动框架*//*obj ----做动画的DOM对象 ；json----变化的部分是json数据 */                      function animate(obj,json) {//调用时先清定时器                clearInterval(obj.timer);//定时器为obj的内部定时器，不用每次调用都创建一个新的定时器                    obj.timer = setInterval(function () {//遍历json数据，每次遍历的标志位为flag                      var flag=true;//遍历json数据，eg:{left:20,top:40,opacity:50,z-index:3}                        for(var key in json){            //取得盒子运动当前的位置            var current= 0;            if(key=="opacity"){                //Ie6,7,8没有设置透明度，默认为undefined                current =Math.round(parseInt(curStyle(obj,key)*100))||1;                //console.log(current);            }else{                current= parseInt(curStyle(obj,key));            }//运动步长：（目标位置-当前位置）/10            var step = (json[key]-current)/10;            step = step>0?Math.ceil(step):Math.floor(step);//各属性值的渐变动画                      if(key=="opacity"){                if("opacity" in obj.style){                    obj.style.opacity = (current+step)/100;                }else{                    //兼容ie6，7，8                    obj.style.filter ="alpha(opacity ="+(current+step)*10+")";                }            }else if(key=="zIndex"){                obj.style[key] =json[key];            }else            {                obj.style[key] = current+step+"px";            }//遍历每个属性时都判断标志位            if(current!=json[key]){                flag =false;            }        }遍历结束后，标志位都为true,判断起所有动画执行完毕，清除定时器        if(flag){            clearInterval(obj.timer);        }    },20)}

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