js 简单的滑动2

作者：Lellansin 转载请标明出处，谢谢


现在我们让滑动多一个功能，三张图、点击左边向左滑动，点右向右滑，碰到临界值的时候可以循环滑动

原理也很将简单，用position:absolute将定位设置成决定定位，通过改变图片相对于绝对位置的坐标来实现滑动。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>js简单的滑动教程（2）</title>

<style type="text/css">
    *{    margin:0; padding:0; }
    li{    list-style: none; }
    #window{ height:200px; 230px;    margin:0 auto; overflow:hidden; }
    #center_window{    height:200px; 160px; float:left; }
    #center_window ul{ height:200px; 160px; position:absolute;overflow:hidden }
    #center_window ul li{ height:200px; 160px; float:left; position:absolute;}
    #center_window img{ display:block; margin:5px auto; }
    #left_arrow{ height:200px; 35px; float:left; background:url("left.png") no-repeat scroll 5px 75px #fff; }
    #left_arrow:hover{ cursor: pointer; }
    #right_arrow{ height:200px;  35px; float:right; background:url("right.png") no-repeat scroll 0px 75px #fff; }
    #right_arrow:hover{ cursor: pointer; }
</style>

</head>

<body>
    <div id="window">
        <div id="left_arrow" onclick="sliderLeft()"></div>
        <div id="center_window">
            <ul>
                <li id="list_0"><img src="img/1.jpg" /></li>
                <li id="list_1"><img src="img/2.jpg" /></li>
                <li id="list_2"><img src="img/3.jpg" /></li>
            </ul>
        </div>
        <div id="right_arrow" onclick="sliderRight()"></div>
    </div>
    <div id="text" style="margin:0 auto;200px;">
    </div>
    
    <script>
        // 图片总数
        var total = 3;
        //当所有图片都显示的时候，所有图片的left都=0，这个时候最后一张图会叠最上面，所以计数器从最后一个开始计数
        var count = total-1;

        function sliderLeft(){    
            // 拼出当前以及左右图片的id
            var left = "list_"+((count+total*100-1)%total);
            var center = "list_"+((count+total*100)%total);
            var right = "list_"+((count+total*100+1)%total);
            // 获取对象
            var pic_left = document.getElementById(left);
            var pic_center = document.getElementById(center);
            var pic_right = document.getElementById(right);
            // 设置坐标
            pic_left.style.left = -160 + "px";
            pic_center.style.left = 0 + "px";
            pic_right.style.left = 160 + "px";
            var i=0;
            var timer = setInterval(function(){
                if(i<=160){
                    //滑动
                    pic_left.style.left = i-160 + "px";
                    pic_center.style.left = i + "px";
                    pic_right.style.left = i+160 + "px";
                    i+=40;
                }else{
                    clearInterval(timer);
                }
            },80);
            // 计数
            count--;            
        }
        function sliderRight(){
            // 拼出id
            var left = "list_"+((count+total*100-1)%total);
            var center = "list_"+((count+total*100)%total);
            var right = "list_"+((count+total*100+1)%total);
            // 获取对象
            var pic_left = document.getElementById(left);
            var pic_center = document.getElementById(center);
            var pic_right = document.getElementById(right);
            //设置坐标
            pic_left.style.left = -160 + "px";
            pic_center.style.left = 0 + "px";
            pic_right.style.left = 160 + "px";
            var i=160;
            var timer = setInterval(function(){
                if(i>=0){
                    // 滑动
                    pic_left.style.left = i - 320 + "px";
                    pic_center.style.left = i - 160 + "px";
                    pic_right.style.left = i + "px";
                    i-=40;
                }else{
                    clearInterval(timer);
                }
            },80);
            // 计数
            count++;
        }
    </script>
</body>
</html>