js动弹特效

<!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>
<style>
#div1 {100px; height:100px; background:red; position:absolute;}
</style>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script>
var iSpeedX=12;
var iSpeedY=8;

function startMove()
{
    setInterval(function (){
        var oDiv=document.getElementById('div1');
        
        iSpeedY+=3;
        
        var l=oDiv.offsetLeft+iSpeedX;
        var t=oDiv.offsetTop+iSpeedY;
        
        if(t>=document.documentElement.clientHeight-oDiv.offsetHeight)
        {
            iSpeedY*=-0.8;
            iSpeedX*=0.8;
            t=document.documentElement.clientHeight-oDiv.offsetHeight;
        }
        else if(t<=0)
        {
            iSpeedY*=-1;
            iSpeedX*=0.8;
            t=0;
        }
        
        if(l>=document.documentElement.clientWidth-oDiv.offsetWidth)
        {
            iSpeedX*=-0.8;
            l=document.documentElement.clientWidth-oDiv.offsetWidth;
        }
        else if(l<=0)
        {
            iSpeedX*=-0.8;
            l=0;
        }
        
        if(Math.abs(iSpeedX)<1)
        {
            iSpeedX=0;
        }
        
        if(Math.abs(iSpeedY)<1)
        {
            iSpeedY=0;
        }
        
        oDiv.style.left=l+'px';
        oDiv.style.top=t+'px';
        
        document.title=iSpeedX;
    }, 30);
}
</script>
</head>

<body>
<input type="button" value="开始运动" onclick="startMove()" />
<div id="div1">
</div>
</body>
</html>
..
原文地址:https://www.cnblogs.com/shoolnight/p/6410510.html