滚动条的实现原理和上一篇文章中的拖拽有很大关系，滑动条就是通过拖拽实现的，通过计算滑动条的拖拽区间来得出一个比例scale，这个就是咱们要用到的文字滚动距离了，
div3里别忘记添加文字
具体代码如下
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>New Web Project</title>
<style>
#parent{
width:600px;
height:20px;
background:#CCCCCC;
position: relative;
}
#div1{
width: 20px;
height:20px;
top:0px;
left:0px;
background:#FF0000;
position: absolute;
}
#div2{
width:300px;
height:300px;
border:1px solid #222222;
position:relative;
margin-top:10px;
overflow:hidden;
}
#div3{
padding:5px;
position: absolute;
}
</style>
<script>
window.onload=function(){
var oParent=document.getElementById('parent');
var oDiv1=document.getElementById('div1');
var oDiv2=document.getElementById('div2');
var oDiv3=document.getElementById('div3');
oDiv1.onmousedown=function(evt){
var e=evt||event;
var disX=e.clientX-oDiv1.offsetLeft;
document.onmousemove=function(evt1){
var e1=evt1||event;
var posX=e1.clientX-disX;
if(posX<0)
{
posX=0;
}
else if(posX>oParent.offsetWidth-oDiv1.offsetWidth)
{
posX=oParent.offsetWidth-oDiv1.offsetWidth;
}
oDiv1.style.left=posX+'px';
var scale=posX/(oParent.offsetWidth-oDiv1.offsetWidth);
oDiv3.style.top=-(oDiv3.offsetHeight-oDiv2.offsetHeight)*scale+'px';
};
document.onmouseup=function(){
document.onmousemove=null;
document.onmouseup=null;
};
return false;
};
};
</script>
</head>
<body>
<div id="parent">
<div id="div1"></div>
</div>
<div id="div2">
<div id="div3">
</div>
</div>
</body>
</html>
运行结果图：
时间： 2024-11-16 18:09:27