日期:2014-05-16  浏览次数:20396 次

利用js实现的温度计效果
<!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=gb2312" />
<title>温度计</title>
<script>
var height=0;//温度计高度
var topvalue=0;//层离上边的高度
var zhi=0;//温度值  温度计高度/100
var currwenduzhi=0;//当前的温度值
var changezhi=0;//要改变的温度值
function textchange()
{

var textvalue=num.value;
if(isNaN(textvalue)||textvalue.length==0)
{
alert('请填写数字');
}else
{
if(textvalue>100){alert('温度值太大');return;}
var v=document.getElementById('test');
if(height==0)
{
height=parseInt(v.style.height.replace('px',''));//得到层的高度
zhi=height/100;//把高度分成100份
}
if(topvalue==0)
{
topvalue=parseInt(v.style.top.replace('px',''));//得到层离上边的距离
}
currwenduzhi=parseInt(v.style.height.replace('px',''))/zhi;//得到当前的温度值
changezhi=parseInt(textvalue);//改变的温度值

setInterval(changes,500);//实现渐动的效果
}
}
function changes()
{
if(currwenduzhi==changezhi)
{
clearInterval(changes);
}
if(currwenduzhi>changezhi)
{
currwenduzhi=currwenduzhi-1;
}else
{
currwenduzhi=currwenduzhi+1;
}
var v=document.getElementById('test');
var value0=zhi*currwenduzhi;
v.style.height=value0+'px';
v.style.top=topvalue+(height-value0)+'px';
}

</script>
</head>

<body>
<div id="test" style="border:1px;background:red;width:4px;height:208px;position:absolute;left:17px;top:26px"></div>
<img  id="wen" src="温度计.JPG"/>
填写温度值:<input name="num" type='text' widht='20' >
<button onclick='textchange()'>改变</button>
</body>
</html>