我需要在div的顶部和中间定位箭头。 div的宽度会动态变化,当我使用left:%50将箭头定位在中间时,它会添加箭头的宽度,因此结果不令人满意。
演示
代码
#wrapper {
display: inline-block;
position: absolute;
padding: 1px;
color: #000;
border: 0px solid #cc3333;
background-color: grey;
}
#wrapper em.out {
position: absolute;
left: 50%;
top: -7px;
display: block;
background: transparent;
border-left: 7px dashed transparent;
border-right: 7px dashed transparent;
border-bottom: 7px solid grey;
overflow: hidden;
}
#wrapper em.inner {
position: absolute;
left: 50%;
top: -7px;
display: block;
background: transparent;
border-left: 7px dashed transparent;
border-right: 7px dashed transparent;
border-bottom: 7px solid grey;
overflow: hidden;
}
<div id="wrapper">
<em class="out"></em>
<em class="inner"></em>
<div>
<div style="margin:1px;background-color:white;">
<option>------John------</option>
</div>
<div style="margin:1px;background-color:white;">
<option>------David------</option>
</div>
<div style="margin:1px;background-color:white;">
<option>------Jennifer------</option>
</div>
<div style="margin:1px;background-color:white;">
<option>------Sue------</option>
</div>
</div>
</div>