javascript小记五则：用JS写一个图片左右自由滚动的“跑马灯”效果

时间 2019-12-08

标签 javascript 一个图片左右自由滚动马灯效果栏目 JavaScript 繁體版

原文原文链接

以前看了不少百度搜索出的东西，十个有九个是不能实用的，个个讲的都不详细，今天详细给你们讲解下关于这个图片“跑马灯”滚动效果，源码以下：javascript

<!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" />
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>js</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, 
user-scalable=no"/>
<style>
*{margin: 0;padding: 0;}
#div1{
    position: relative;border: 1px solid gray;
    width: 100%;
    margin: 20px auto;
    height: 500px;
    overflow: hidden;
}
#div1 ul{
    position: absolute;
    left: 0;
}
#div1 a{
    position: absolute;
    z-index: 2;
    text-decoration: none;
    top: 45%;
    display: none;
}
#div1 ul li{
    padding: 5px;
    list-style: none;
    width: 400px;
    height: 500px;
    float: left;
}
#div1 ul li img{
    width: 100%;
    height: 100%;
}
</style>
</head>
<body>
<script type="text/javascript">
    window.onload = function(){
        var oDiv = document.getElementById('div1');
        var oUl = oDiv.getElementsByTagName('ul')[0];
        var aLi = oUl.getElementsByTagName('li');
        var aA = oDiv.getElementsByTagName('a');
        var iSpeed = 1;
        var timer = null;
        //计算ul的宽为全部li的宽的和;
        oUl.innerHTML += oUl.innerHTML+oUl.innerHTML;
        oUl.style.width = aLi[0].offsetWidth*aLi.length+'px';
        function Slider(){
            if (oUl.offsetLeft<-oUl.offsetWidth/2) {
                oUl.style.left = 0;
            }else if(oUl.offsetLeft>0){
                oUl.style.left =-oUl.offsetWidth/2+'px';
            }
            oUl.style.left = oUl.offsetLeft-iSpeed+'px';
        }
        timer =setInterval(Slider,30);
        aA[0].onclick = function(){
            iSpeed = 1;
        }
        aA[1].onclick = function(){
            iSpeed = -1;
        }
        oDiv.onmouseover = function(){
            clearInterval(timer);
        }
        oDiv.onmouseout = function(){
            timer =setInterval(Slider,30);
        }
    };
</script>
<div id="div1">
    <ul>
        <li><img src="../JPG/01.jpg"></li>
        <li><img src="../JPG/02.jpg"></li>
        <li><img src="../JPG/03.jpg"></li>
        <li><img src="../JPG/04.jpg"></li>
    </ul>
    <a href="javascript:;" style="left:10px;"><</a>
    <a href="javascript:;" style="right:10px;">></a>
</div>
</body>
</html>

标注：头部说明html

一、头部；<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />这条能够在博客园搜索下，里面讲的很详细；java

二、<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">：这句话的意思是强制IE浏览器使用谷歌框架进行渲染，简单的说这跟浏览器的兼容性有关；web

三、<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"/>：这一条有兴趣的话能够到CSDN上查找相关说明，很是详细；chrome

代码块详解一：怎样改变图片滚动的方向浏览器

    var oDiv = document.getElementById('div1');
        var oUl = oDiv.getElementsByTagName('ul')[0];
        var aLi = oUl.getElementsByTagName('li');
        var aA = oDiv.getElementsByTagName('a');
        var iSpeed = 1;//正左负右（改成-1从左到右滚动、1为从右往左滚动）

代码块详解二：怎样修改图片滚动时间快慢框架

    timer =setInterval(Slider,30);
        aA[0].onclick = function(){
            iSpeed = 1; //控制速度的正负
        }
        aA[1].onclick = function(){
            iSpeed = -1;
        }
        oDiv.onmouseover = function(){
            clearInterval(timer);
        }
        oDiv.onmouseout = function(){
            timer =setInterval(Slider,30);
        }

代码块详解三：哪里替换图片，图片是怎么来的ide

        <li><img src="../JPG/01.jpg"></li>
        <li><img src="../JPG/02.jpg"></li>
        <li><img src="../JPG/03.jpg"></li>
        <li><img src="../JPG/04.jpg"></li>

图片路径根据我的web中存放的图片路径进行修改，放多少都没问题；ui

代码块详解四：修改图片大小，控制图片的高宽，找到对应修改便可spa

*{margin: 0;padding: 0;}
#div1{
    position: relative;border: 1px solid gray;
    width: 100%;
    margin: 20px auto;
    height: 500px;
    overflow: hidden;
}
#div1 ul{
    position: absolute;
    left: 0;
}
#div1 a{
    position: absolute;
    z-index: 2;
    text-decoration: none;
    top: 45%;
    display: none;
}
#div1 ul li{
    padding: 5px;
    list-style: none;
    width: 400px;
    height: 500px;
    float: left;
}
#div1 ul li img{
    width: 100%;
    height: 100%;
}