摘要：<!DOCTYPE html><head><meta charset="utf-8"><style type="text/css"> #fdivtest { width: 100px; height: 100px; background-color: green; }</style><scr
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<style type="text/css">
#fdivtest
{
width: 100px; height: 100px; background-color: green;
}
</style>
<script type="text/javascript">
var desdiv;
function showTime(){
nowtime=new Date();
year=nowtime.getFullYear();
month=nowtime.getMonth()+1;
date=nowtime.getDate();
document.getElementById("mytime").innerText=year+"年"+month+"月"+date+" "+nowtime.toLocaleTimeString();
}
window.onload = function ()
{
desdiv = window.document.getElementById("fdivtest");
}
//setInterval("showTime()",1000);
function changecss(vpara)
{
// alert(desdiv.innerText);
//alert(desdiv.style.width);
switch (vpara)
{
case 0:
//desdiv.style.width = "300px;";
desdiv.style.cssText='width:300px;';
break;
case 1:
desdiv.style.cssText='height:300px;';
break;
case 2:
//desdiv.style.setProperty('backgroundColor', 'blue', 'important');
desdiv.style.cssText='background-color: blue';
break;
case 3:
//desdiv.style.setProperty('backgroundColor', 'blue', 'important');
desdiv.style.cssText= "";
break;
case 4:
//desdiv.style.setProperty('backgroundColor', 'blue', 'important');
desdiv.style.cssText= "display: none";
break;
case 5:
//desdiv.style.setProperty('backgroundColor', 'blue', 'important');
desdiv.style.cssText= "display: block";
break;
}
}
function aa() {
var oStyle = desdiv.currentStyle? desdiv.currentStyle : window.getComputedStyle(desdiv, null);
alert(oStyle.getPropertyValue("width"));
var width = desdiv.style.width;
// alert(width);
//desdiv.style.width = "300px;";
desdiv.style.cssText='width:300px;'
}
</script>
</head>
<body>
<div id="fdivtest" >
asdfasdf
</div>
<input type="button" onclick="changecss(0)" value="变宽">
<input type="button" onclick="changecss(1)" value="变高">
<input type="button" onclick="changecss(2)" value="变背景色">
<input type="button" onclick="changecss(3)" value="重置">
<input type="button" onclick="changecss(4)" value="隐藏">
<input type="button" onclick="changecss(5)" value="显示">
<span id="mytime"></span>
</body>
</html>
批改老师：天蓬老师批改时间：2019-01-04 16:05:28
老师总结：desdiv = window.document.getElementById("fdivtest"); 不要这样创建变量, 一定要在前面添加var或者 let / const, 这样才能与一个作用域进行绑定,否则就直接绑定到全局了
