一、最终效果
二、功能分析1、需求分析点击左边PRe按钮，显示前面三个图片，点击右边的next按钮，显示后面的一组（三个）图片。初始化只显示next按钮，到最后一组只显示pre按钮，中间过程两按钮都显示。
2、html结构分析
<divclass="activity"id="activity-slide"><ahref="javascript:void(0)"class="pg_left ps_pre"></a><ahref="Javascript:void(0)"class="pg_right ps_next"></a><ulclass="clearfix"><li><ahref="javascript:;"><imgsrc="images/activity01-1410.jpg"></a></li><li><ahref="javascript:;"><imgsrc="images/activity02-1410.jpg"></a></li><li><ahref="javascript:;"><imgsrc="images/activity03-1410.jpg"></a></li><li><ahref="javascript:;"><imgsrc="images/activity03-1410.jpg"></a></li><li><ahref="javascript:;"><imgsrc="images/activity02-1410.jpg"></a></li></ul></div>
#activity-slide是整个幻灯的入口，后面会将其作为参数来调用幻灯功能。
两个按钮ps_pre和ps_next将添加click事件响应点击切换功能。
3、功能分析因为左右切换都是三个为一组的切换，如果li总个数不是3的倍数时，需要增加li节点填满。
//需要追加的li节点个数var addli = 0;//一组切换3个livar num=3;var lisize = a.find("ul li").size();//获取li个数//判断需要添加的li节点数量var reminder=lisize%num;if(lisize%num!=0){addli = num-reminder;}else{addli = 0;}
addlist();
上面是判断得到需要追加的个数lisize，然后调用addlist追加。
addlist如下，从ul的第一个li开始复制，需要几个就复制出几个节点追加。节点追加完毕后重新计算ul的宽度。
functionaddlist(){for(i=0;i<addli;i++){var html = a.find("ul li").eq(i).html();
a.find("ul").append("<li>"+html+"</li>");
}
a.find("ul").CSS({"width":(w_li+margin_li*2)*(lisize+addli)});
}
现在准备工作已经完成了。接下来就是给按钮添加响应事件。在幻灯切换时涉及到左右按钮的显示和隐藏，所以先说这个按钮显示功能，将此分装成一个函数btnshow。
/***
参数说明：
now:当前是第几组，默认是0
c:总共有几组
d:初始化时li的个数
e:每组显示li个数
***/functionbtnshow(now,c,d,e){if(d<=e){//如果初始化时li的个数小于一组要显示的数，则不显示pre和next按钮
a.find(".ps_next").hide();
a.find(".ps_pre").hide();
}elseif(now==0){//初始化now=0，显示第一组，只显示next
a.find(".ps_next").show();
a.find(".ps_pre").hide();
}elseif(now==c-1){//显示到最后一组，只显示pre
a.find(".ps_next").hide();
a.find(".ps_pre").show();
}else{//显示中间组，pre和next都需要显示
a.find(".ps_next").show();
a.find(".ps_pre").show();
}
}
接下来幻灯切换。这里a是传入的参数，也就是 #activity-slide。给它下面的所以的pre和next添加响应。
向前一组，组数now减一，now是几，就让ul的margin-left为负几倍的组宽（即3倍的（li宽度+margin宽度）），然后显示对于按钮即可。
向后滑动一组li同理。
functionphotoscroll(){
a.find(".ps_pre").on("click",function(){//console.log(num);
now--;if(now >= 0){
a.find("ul").animate({"margin-left":-now*num*(w_li+margin_li*2)});
btnshow(now,parseInt((lisize+addli)/num),lisize,num);}
});
a.find(".ps_next").on("click",function(){//console.log(num);
now++;if(now < (lisize+addli)/num){
a.find("ul").animate({"margin-left":-now*num*(w_li+margin_li*2)});
btnshow(now,parseInt((lisize+addli)/num),lisize,num);}
});
btnshow(now,parseInt((lisize+addli)/num),lisize,num);
}
三、代码1、用到图片
2、完整代码完整代码
<!DOCTYPE HTML><html><head><metacharset="utf-8"><title></title><linkrel="stylesheet"type="text/css"href="css/style.css"><script>window.onresize=function(){varwinWidth=document.body.clientWidth;if(winWidth<=1180){
body.className="grid-960";
}elseif(winWidth<=1410){
body.className="grid-1180";
}elseif(winWidth>1410){
body.className="grid-1410";
}else{
alert("do not know!");
}
}</script></head><bodyid="body"class=""><script>//初始化状态显示样式判断,放在body后面varwinWidth=document.body.clientWidth;if(winWidth<=1180){
body.className="grid-960";
}elseif(winWidth<=1410){
body.className="grid-1180";
}elseif(winWidth>1410){
body.className="grid-1410";
}else{
alert("do not know!");
}</script><divclass="wapper"><divclass="section"><h2class="title">热门活动</h2><divclass="activity"class="movie"id="activity-slide"><ahref="javascript:void(0)"class="pg_left ps_pre"></a><ahref="javascript:void(0)"class="pg_right ps_next"></a><ulclass="clearfix"><li><ahref="javascript:;"><img src="images/activity01-1410.jpg"></a></li>
<li><a href="javascript:;"><img src="images/activity02-1410.jpg"></a></li>
<li><a href="javascript:;"><img src="images/activity03-1410.jpg"></a></li>
<li><a href="javascript:;"><img src="images/activity03-1410.jpg"></a></li>
<li><a href="javascript:;"><img src="images/activity02-1410.jpg"></a></li>
</ul>
</div>
</div>
</div>
</body>
</html>
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script>
//首页图片滚动切换
(function($){
$.photolist=function(a){
var w_li = a.find("li").width();
var h_li = a.find("li").height();
var margin_li=parseInt(a.find("li").css("marginLeft"));
var now = 0;
var num = 0;
var addli = 0;
var lisize = a.find("ul li").size();
var htmlall = a.find("ul").html();
//判断每次滚动数量
/*
var w_body = $("body").width();
if(w_body <=1170){
var num = 3;
}else if(w_body<= 1380){
var num = 4;
}else if(w_body>1380){
var num = 5;
}
*/
var num=3;
//判断需要添加的li节点数量
var reminder=lisize%num;
if(lisize%num!=0){addli = num-reminder;}
else{addli = 0;}
addlist();
//点击滚动事件
photoscroll();
$(window).resize(function(){
//location.reload();
now = 0;
addli = 0;
a.find("ul").html(htmlall);//html内容还原初始值
a.find(".ps_next").show();//按钮样式初始化
a.find(".ps_pre").hide();
//判断每次滚动数量
/*
var w_body = $("body").width();
if(w_body <=1170){
var num = 3;
}else if(w_body<= 1380){
var num = 4;
}else if(w_body>1380){
var num = 5;
}
*/
var num=3;
//判断需要添加的li节点数量
var reminder=lisize%num;
if(lisize%num!=0){addli = num-reminder;}
else{addli = 0;}
addlist();
w_li = a.find("li").width();
margin_li=parseInt(a.find("li").css("marginLeft"));
a.find("ul").css({"width":(w_li+margin_li*2)*(lisize+addli)});
a.find("ul").animate({"margin-left":0});//ul位置还原
btnshow(now,parseInt((lisize+addli)/num),lisize,num);
});
function addlist(){
for(i=0;i<addli;i++){
var html = a.find("ul li").eq(i).html();
a.find("ul").append("<li>"+html+"</li>");
}
a.find("ul").css({"width":(w_li+margin_li*2)*(lisize+addli)});
//console.log(a.find("ul li").size());
}
function photoscroll(){
a.find(".ps_pre").on("click",function(){//console.log(num);
now--;
if(now >= 0){
a.find("ul").animate({"margin-left":-now*num*(w_li+margin_li*2)});
btnshow(now,parseInt((lisize+addli)/num),lisize,num);
}
});
a.find(".ps_next").on("click",function(){//console.log(num);
now++;
if(now < (lisize+addli)/num){
a.find("ul").animate({"margin-left":-now*num*(w_li+margin_li*2)});
btnshow(now,parseInt((lisize+addli)/num),lisize,num);
}
});
btnshow(now,parseInt((lisize+addli)/num),lisize,num);
}
/***
参数说明：
now:当前是第几组，默认是0
c:总共有几组
d:初始化时li的个数
e:每组显示li个数
***/
function btnshow(now,c,d,e){
if(d<=e){//如果初始化时li的个数小于一组要显示的数，则不显示pre和next按钮
a.find(".ps_next").hide();
a.find(".ps_pre").hide();
}else if(now==0){//初始化now=0，显示第一组，只显示next
a.find(".ps_next").show();
a.find(".ps_pre").hide();
}else if(now==c-1){//显示到最后一组，只显示pre
a.find(".ps_next").hide();
a.find(".ps_pre").show();
}else{//显示中间组，pre和next都需要显示
a.find(".ps_next").show();
a.find(".ps_pre").show();
}
}
}
})(jQuery);
$.photolist($("#activity-slide"));
</script>
css部分：
@charset "utf-8";
body, div, h1, h2, h3, h4, h5, h6, hr, p, blockquote, dl, dt, dd, ul, ol, li, pre, code, form, fieldset, legend, button, textarea, table, tbody, tfoot, thead, th, td, article, aside, dialog, figure, footer, header, hgroup, menu, nav, section, time, mark, audio, video {margin:0;padding:0;outline:nonebackground:transparent;
}article, aside, dialog, figure, footer, header, hgroup, nav, section {display:block; }body, button, input, select, textarea {font:12px/1.5 arial, \5b8b\4f53, sans-serif; }h1, h2, h3, h4, h5, h6, button, input, select, textarea {font-size:100%;outline:none }address, cite, dfn, em, var {font-style:normal; }code, kbd, pre, samp {font-family:courier new, courier, monospace; }small {font-size:12px; }ul, ol, li {list-style:none; }img {border:none; }a {text-decoration:none;outline:thin none; }a:hover {text-decoration:underline; }table {border-collapse:collapse;border-spacing:0; }.clear {clear:both; }.clearfix:after {visibility:hidden;display:block;font-size:0;content:" ";clear:both;height:0; }html {-webkit-text-size-adjust:none; }body {font:12px/1.5 \5FAE\8F6F\96C5\9ED1, tahoma, arial, \5b8b\4f53, sans-serif; }.grid-960 .wapper {width:100%;min-width:960px;height:auto;margin:0 auto;background:url(../images/bg-body-960.jpg) no-repeat center top; }.grid-1180 .wapper {width:100%;min-width:1180px;height:auto;margin:0 auto;background:url(../images/bg-body-1180.jpg) no-repeat center top; }.grid-1410 .wapper {width:100%;min-width:1410px;height:auto;margin:0 auto;background:url(../images/bg-body-1410.jpg) no-repeat center top; }/*热门活动*/.grid-960 .section {width:960px;margin:0 auto;background-color:#eaf2ff; }.grid-1180 .section {width:1180px;margin:0 auto;background-color:#eaf2ff;}.grid-1410 .section {width:1410px;margin:0 auto;background-color:#eaf2ff;}.title{padding:0 102px;height:70px;line-height:70px;font-size:24px;font-weight:normal;color:#fff;text-shadow:0 3px #df2828, 3px 0 #df2828;background:#cc2223 url(../images/bg-title.jpg) no-repeat left top;}.viewall:hover{text-decoration:none;}.viewall{font-size:18px;;color:#fff;text-shadow:0 3px #df2828, 3px 0 #df2828;float:right;}.grid-1410 .title {padding:0 116px;background-image:url(../images/bg-title-1410.jpg);}.grid-960 .contentwrap{width:800px;margin:0 auto;}.grid-1180 .contentwrap{width:980px;margin:0 auto;}.grid-1410 .contentwrap{width:1180px;margin:0 auto;}.grid-960 .activity{width:826px;height:152px;overflow:hidden;margin:0 auto;position:relative;}.grid-1180 .activity{width:1020px;height:192px;overflow:hidden;margin:0 auto;position:relative;}.grid-1410 .activity{width:1230px;height:232px;overflow:hidden;margin:0 auto;position:relative;}
.grid-960 .activity ul{height:152px;overflow:hidden;}
.grid-1180 .activity ul{height:192px;overflow:hidden;}
.grid-1410 .activity ul{height:232px;overflow:hidden;}
.activity li img{display:block;width:100%;height:100%;}
.activity li{display:block;float:left;}
.grid-960 .activity li{width:250px;height:125px;overflow:hidden;margin:12px;}
.grid-1180 .activity li{width:300px;height:150px;overflow:hidden;margin:20px;}
.grid-1410 .activity li{width:360px;height:180px;overflow:hidden;margin:25px;}
/*js切换*/
.pg_left,.pg_right {position: absolute;z-index: 999;width: 35px;height: 50px;overflow: hidden;}
.pg_right {background: transparent url(../images/pg_right.png) no-repeat scroll 5px 7px;}
.pg_right:hover {background: transparent url(../images/hover.png) no-repeat scroll 0 0;}
.grid-960 .pg_right{top:75px;right:16px;margin-top:-25px;}
.grid-1180 .pg_right{top:95px;right:20px;margin-top:-25px;}
.grid-1410 .pg_right{top:115px;right:25px;margin-top:-25px;}
.pg_left {background: transparent url(../images/pg_left.png) no-repeat scroll 5px 7px;}
.pg_left:hover {background: transparent url(../images/hover.png) no-repeat scroll right 0;}
.grid-960 .pg_left{top:75px;left:13px;margin-top:-25px;}
.grid-1180 .pg_left{top:95px;left:20px;margin-top:-25px;}
.grid-1410 .pg_left{top:115px;left:25px;margin-top:-25px;}