原生js编写焦点图效果

<div class="focusPicture">          <section class="mPhoto" id="mPhoto">            <img src="images/20161021/b_5809b93b66d18.jpg"/>          </section><!-- 主要的大图 -->          <section class="oPhoto">            <div class="imgWrap">              <section class="on">                <img src="images/20161021/b_5809b93b66d18.jpg"/>              </section>              <section>                <img src="images/20161021/b_5809b96c4da53.jpg"/>              </section>              <section>                <img src="images/20161021/b_5809b9bea39c4.jpg"/>              </section>              <section>                <img src="images/20161021/b_5809ba288384e.jpg"/>              </section>              <section>                <img src="images/20161021/b_5809bae42fa81.jpg"/>              </section>              <section>                <img src="images/20161021/b_5809ba288384e.jpg"/>              </section>              <section>                <img src="images/20161021/b_5809bb3da0bbc.jpg"/>              </section>            </div>          </section><!-- 其他的小图 -->          <section class="prevNext">            <div class="prev">              <i></i>            </div><!-- 上一张 -->            <div class="next">              <i></i>            </div><!-- 下一张 -->          </section><!-- 上下翻页 --></div><!-- 焦点图区 -->

window.onload = function(){ /*焦点图特效*/ var mPhoto = document.getElementById("mPhoto"); var imgWrap = document.getElementsByClassName("imgWrap")[0]; var wrapSize = 4; /*图片容器最大显示图片数*/ if(imgWrap.getElementsByTagName("section").length>wrapSize){  imgWrap.innerHTML = imgWrap.innerHTML+imgWrap.innerHTML; }  var oImages = imgWrap.getElementsByTagName("section"); for(var i = 0 ; i<oImages.length; i++) {  oImages[i].onmouseover = function()  {   for(var j = 0 ; j<oImages.length; j++)   {    removeClass(oImages[j],"on");   }   var imgSrc = this.getElementsByTagName("img")[0].src;   addClass(this,"on");   mPhoto.getElementsByTagName("img")[0].src = imgSrc;  } } /*上下翻页容器*/ var oPrevNext = document.getElementsByClassName("prevNext")[0]; var oPrev = oPrevNext.getElementsByClassName("prev")[0]; var oNext = oPrevNext.getElementsByClassName("next")[0]; var oImageHeight = oImages[0].getElementsByTagName("img")[0].height||0; var oPositionTop = imgWrap.offsetTop; var imgIndex = 0;  if(oImages.length>wrapSize*2) {  oPrev.style.display = "block";  oNext.style.display = "block"; }  /*上一页*/ oPrev.onclick=function() {  imgIndex-=1;  if(imgIndex<=0){   imgIndex = 6;  }  var oTop = imgIndex*(oImageHeight+8);  imgWrap.style.top = -oTop+"px";    /*获取当前图片的索引*/  for(var i = 0 ; i<oImages.length; i++)  {   var oBol = hasClass(oImages[i],"on")||false;   if(oBol){    var index = oIndex(oImages[i],oImages);    index=index-1;    if(imgIndex==6){     index = 6;    }    for(var j = 0 ; j<oImages.length; j++)    {/*清除其他的图片on样式*/     removeClass(oImages[j],"on");    }    addClass(oImages[index],"on");    var imgSrc = oImages[index].getElementsByTagName("img")[0].src;    mPhoto.getElementsByTagName("img")[0].src = imgSrc;    return false;   }  } }  /*下一页*/ oNext.onclick = function() {  imgIndex+=1;  if(imgIndex>=6){   imgIndex = 0;  }  var oTop = imgIndex*(oImageHeight+8);  imgWrap.style.top = -oTop+"px";    /*获取当前图片的索引*/  for(var i = 0 ; i<oImages.length; i++)  {   var oBol = hasClass(oImages[i],"on")||false;   if(oBol){    var index = oIndex(oImages[i],oImages);    index=index+1;    if(imgIndex==0){     index = 1;    }    for(var j = 0 ; j<oImages.length; j++)    {/*清除其他的图片on样式*/     removeClass(oImages[j],"on");    }    addClass(oImages[index],"on");    var imgSrc = oImages[index].getElementsByTagName("img")[0].src;    mPhoto.getElementsByTagName("img")[0].src = imgSrc;    return false;   }  } }}function hasClass(element,cName){//检查class是否存在 return !!element.className.match(new RegExp('(//s|^)'+cName+'(//s|$)'));}function addClass(element,cName){//添加一个class if(!hasClass(element,cName)) {  element.className +=' '+cName; }}function removeClass(element,cName){//移除一个class if(hasClass(element,cName)) {  element.className = element.className.replace(new RegExp('(//s|^)'+cName+'(//s|$)'),' '); }}function oIndex(current, obj){/*获取索引*/ for (var i = 0, length = obj.length; i<length; i++) {   if (obj[i] == current)  {    return i;   }  } }

.productInfo .focusPicture{ width: 698px; float: left; position: relative; border-right: 1px solid #d9cdb4;}.productInfo .focusPicture .mPhoto{ width: 542px; height: 360px;}.productInfo .focusPicture .mPhoto img{ width: 100%; height: 100%;}.productInfo .focusPicture .oPhoto{ width: 128px; height: 352px; position: absolute; right: 14px; top: 4px; overflow: hidden;}.productInfo .oPhoto div{ width: 128px; position: absolute; left:0; top:0; -webkit-transition: top .2s ease-out; -moz-transition: top .2s ease-out; transition: top .2s ease-out; }.productInfo .oPhoto section{ height: 78px; margin: 8px 0; position: relative; cursor: pointer;}.productInfo .oPhoto section::before { content: ""; display: block; width: 100%; height: 100%; background-color: rgba(255,255,255,.42); position: absolute; left: 0; top: 0;}.productInfo .oPhoto section.on::before{ display: none;}.productInfo .focusPicture .oPhoto img{ width: 100%; height: 100%;}.productInfo .focusPicture .prevNext{ width: 32px; height: 32px; position: absolute; top: -4px; right: 62px;}.productInfo .prevNext div.prev,.productInfo .prevNext div.next{ width: 32px; height: 32px; -webkit-border-radius: 50%; -moz-border-radius: 50%; border-radius: 50%; background-color: #fff; position: absolute; left: 0; -webkit-transition: all .25s; -moz-transition: all .25s; transition: all .25s; display: none; cursor: pointer;}.productInfo .prevNext div.prev{ top: 0; box-shadow: 0 -2px 4px rgba(0,0,0,.24);}.productInfo .prevNext div.next{ top: 336px; box-shadow: 0 2px 4px rgba(0,0,0,.24);}.productInfo .prevNext div.prev:hover{ box-shadow: 2px -2px 3px rgba(0,0,0,.24);}.productInfo .prevNext div.next:hover{ box-shadow: -2px 2px 3px rgba(0,0,0,.24);}.productInfo .prevNext div.prev i,.productInfo .prevNext div.next i{ width: 16px; height: 16px; position: absolute; top: 0; right: 0; bottom: 0; left: 0; margin: auto; cursor: pointer;}.productInfo .prevNext div.prev i{ background: url(../images/arrows-icon.png) 0 -16px no-repeat; background-size: 48px 32px; bottom: 2px;}.productInfo .prevNext div.next i{ background: url(../images/arrows-icon.png) 0 0 no-repeat; background-size: 48px 32px; top: 2px;}.productInfo .prevNext div.prev:hover i,.productInfo .prevNext div.next:hover i{ -webkit-transform: scale(1.1); -moz-transform: scale(1.1); transform: scale(1.1);}.productInfo .prevNext div.prev:hover i{ background: url(../images/arrows-icon.png) -16px -16px no-repeat; background-size: 48px 32px;}.productInfo .prevNext div.next:hover i{ background: url(../images/arrows-icon.png) -16px 0px no-repeat; background-size: 48px 32px;}.productInfo .prevNext div.prev:active i{ background: url(../images/arrows-icon.png) -32px -16px no-repeat; background-size: 48px 32px;}.productInfo .prevNext div.next:active i{ background: url(../images/arrows-icon.png) -32px 0px no-repeat; background-size: 48px 32px;}