jquery——左右按钮点击切换一组图片功能

2022-11-22 12:46:27

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

 <div class="activity" id="activity-slide">

        <a href="javascript:void(0)" class="pg_left ps_pre"></a>

        <a href="javascript:void(0)" class="pg_right ps_next" ></a>

          <ul class="clearfix">

            <li><a href="javascript:;"><img src="data:images/activity01-1410.jpg"></a></li>

            <li><a href="javascript:;"><img src="data:images/activity02-1410.jpg"></a></li>

            <li><a href="javascript:;"><img src="data:images/activity03-1410.jpg"></a></li>

            <li><a href="javascript:;"><img src="data:images/activity03-1410.jpg"></a></li>

            <li><a href="javascript:;"><img src="data: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li

var 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。

        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)});

        }

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

        ***/

        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();

            }

        }

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。

        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);

        }

三、代码

1、用到图片

2、完整代码

完整代码

<!DOCTYPE HTML>

<html>

<head>

<meta charset="utf-8">

<title></title>

<link rel="stylesheet" type="text/css" href="css/style.css">

<script>

window.onresize=function(){

    var winWidth = document.body.clientWidth;

    if(winWidth <=1180){

        body.className="grid-960";

    }else  if (winWidth<= 1410){

        body.className="grid-1180";

    }else if (winWidth>1410){

        body.className="grid-1410";

    }else {

        alert("do not know!");

    }

}

</script>

</head>

<body id="body" class="">

<script>//初始化状态显示样式判断,放在body后面

var winWidth = document.body.clientWidth;

if (winWidth <=1180){

    body.className="grid-960";

}else  if (winWidth<= 1410){

    body.className="grid-1180";

}else if (winWidth>1410){

    body.className="grid-1410";

}else {

    alert("do not know!");

}

</script>

<div class="wapper">

    <div class="section">

        <h2 class="title">热门活动</h2>

        <div class="activity" class="movie" id="activity-slide">

            <a href="javascript:void(0)" class="pg_left ps_pre"></a>

            <a href="javascript:void(0)" class="pg_right ps_next" ></a>

            <ul class="clearfix">

                <li><a href="javascript:;"><img src="data:images/activity01-1410.jpg"></a></li>

                <li><a href="javascript:;"><img src="data:images/activity02-1410.jpg"></a></li>

                <li><a href="javascript:;"><img src="data:images/activity03-1410.jpg"></a></li>

                <li><a href="javascript:;"><img src="data:images/activity03-1410.jpg"></a></li>

                <li><a href="javascript:;"><img src="data: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;}

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