关于className的一个问题

seven.onclick=function () {
box.className="box";

}

.box{width: 100px;height:100px;border:5px solid black;float: left;margin-left:20px;margin-top: 20px;
clear:both;}

设置了个点击触发函数。但是这个box的盒子的css并没有改变。求解

全代码：*{margin: 0;padding:0;}
/*body{background-color: #5a5b5b}*/
.zhezhao
{
width:100%;
height:100%;
background-color:#000;
/*透明三部曲，一般都要写上/
;/*opacity:0.5;
-moz-opacity:0.5;
filter:alpha(opacity=50);*/
filter:alpha(opacity=50);
-moz-opacity:0.5;
opacity:0.5;
position:absolute;
left:0;
top:0;
display:none;
z-index:1000;
}

#box{width: 100px;height:100px;border:5px solid black;float: left;margin-left:20px;margin-top: 20px;
clear:both;}
.box{width: 100px;height:100px;border:5px solid black;float: left;margin-left:20px;margin-top: 20px;
clear:both;}
.box1{position: absolute;bottom:20px;right:20px;width:320px;height:300px;border:5px solid #5a5b5b;
padding:20px;display: none; z-index:1500;}
.option1 span{;border:1px solid black;display: inline;margin-left: 20px;padding: 5px;cursor: pointer;}
.option2{margin-top: 50px;}
.option2 span{border:1px solid black;display: inline;margin-left: 20px;padding: 5px; cursor: pointer;}
.option3{margin-top: 50px;}
.option3 span{border:1px solid black;display: inline;margin-left: 20px;padding: 5px; cursor: pointer}
.option4{margin-top: 50px;margin-left:100px;}
.option4 span{border:1px solid black;display: inline;margin-left: 20px;padding: 5px;text-align: center;cursor: pointer}
/* span在设置了inline后width属性失效了；*/
</style>
<script>
window.onload=function () {
function rest(obj) {
obj.style.width="100px";
obj.style.height="100px";
obj.style.border="5px solid black";
obj.style.background="none";
}
var zhezhao=document.getElementById("zhezhao");
var obtn=document.getElementById("btn");
var red=document.getElementById("red");
var yellow=document.getElementById("yellow");
var green =document.getElementById("green");
var three=document.getElementById("three");
var four=document.getElementById("four");
var five=document.getElementById("five");
var sex=document.getElementById("sex");
var seven=document.getElementById("seven");
var eight=document.getElementById("eight");
obtn.onclick = function () {
box1.style.display = "block";
zhezhao.style.display = "block";
};
eight.onclick=function () {
box1.style.display="none";
};
red.onclick=function () {
box.style.backgroundColor="red";
};
yellow.onclick=function () {
box.style.backgroundColor="yellow";
};
green.onclick=function () {
box.style.backgroundColor="green";
};
one.onclick=function () {
box.style.width="200px";
};
two.onclick=function () {
box.style.width="300px";
};
three.onclick=function () {
box.style.width="400px";
};
four.onclick=function () {
box.style.height="200px";
};
five.onclick=function () {
box.style.height="300px";
};
sex.onclick=function () {
box.style.height="400px";
};
seven.onclick=function () {
box.className="box";
};
eight.onclick=function () {
box1.style.display="none";
zhezhao.style.display = "none";
};
}
</script>
</head>
<body>
<div class="zhezhao" id="zhezhao"></div>
<span>请为下面的的DIV设置样式：</span>
<input id="btn" type="button" value="点击设置样式"/>
<div>
<div id="box"></div>
</div>
<div class="box1" id="box1">
<div class="option1">
选择背景：
<span id="red" style="background: red">红</span>
<span id="yellow" style="background: yellow">黄</span>
<span id="green" style="background: green">绿</span>
</div>
<div class="option2">
选择宽度：
<span id="one">200</span>
<span id="two">300</span>
<span id="three">400</span>
</div>
<div class="option3">
选择宽度：
<span id="four">200</span>
<span id="five">300</span>
<span id="sex">400</span>
</div>
<div class="option4">
<span id="seven">恢复</span>
<span id="eight"> 确定</span>
</div>
</div>

qq_药药_0

浏览 1903回答 3

3回答

慕的地6079101

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qq_药药_0

搞懂了，是写入css的优先级有问题，写成内联式就有效果了

qq_小盛开_0

box 取到了么？

qq_药药_0

好了啊

落叶1111

[0]

蜂之谷

代码贴全看，这些看着没什么问题啊

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