使用CSS3插入border-radius

Question

有没有办法用css3创建插入边框半径？(没有图像)

我需要这样的边界半径:

Answer 1

我发现使用所有CSS和HTML(没有图像等)来实现这一点的最好方法是使用每个Lea Verou的CSS3渐变.从她的解决方案:

div.round {
    background:
        -moz-radial-gradient(0 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
        -moz-radial-gradient(100% 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
        -moz-radial-gradient(100% 0, circle, rgba(204,0,0,0) 14px, #c00 15px),
        -moz-radial-gradient(0 0, circle, rgba(204,0,0,0) 14px, #c00 15px);
    background:
         -o-radial-gradient(0 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
         -o-radial-gradient(100% 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
         -o-radial-gradient(100% 0, circle, rgba(204,0,0,0) 14px, #c00 15px),
         -o-radial-gradient(0 0, circle, rgba(204,0,0,0) 14px, #c00 15px);
    background:
         -webkit-radial-gradient(0 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
         -webkit-radial-gradient(100% 100%, circle, rgba(204,0,0,0) 14px, #c00 15px),
         -webkit-radial-gradient(100% 0, circle, rgba(204,0,0,0) 14px, #c00 15px),
         -webkit-radial-gradient(0 0, circle, rgba(204,0,0,0) 14px, #c00 15px);
    background-position: bottom left, bottom right, top right, top left;
        -moz-background-size: 50% 50%;
        -webkit-background-size: 50% 50%;
    background-size: 50% 50%;
    background-repeat: no-repeat;
}

最终结果是一组带曲线的透明渐变.查看完整的JSFiddle以获得演示并了解它的外观.

显然,这取决于支持rgba和gradient,因此应被视为一个渐进增强,或者如果它是必不可少的设计,你应该提供对旧的浏览器(尤其是IE浏览器,不支持基于图像的回退gradient通过IE9甚至达到).

Answer 2

您可以通过使用框阴影在角落中绝对定位透明圆形元素来实现此目的.我使用了包含跨度,框阴影,边框和伪选择器的隐藏溢出div的组合.

看看我的例子.

这是您需要开始的基本HTML和CSS:

a {display:inline-block; width:250px; height:100px; background:#ccc; border:2px solid #000; position:relative; margin:10px;}

a div {position: absolute; top: 0; overflow: hidden; width: 15px; height: 100%;}
a div:after {content:''; background:#000; width:2px; height:75px; position:absolute; top:12.5px;}

a div:first-of-type {left: -14px;}
a div:first-of-type:after {left:0;}

a div:last-of-type {right: -14px;}
a div:last-of-type:after {right:0;}

a span {display:block; width:30px; height:30px; background:transparent; position:absolute; bottom:-20px; right:-20px; border:2px solid #000; border-radius:25px; box-shadow:0 0 0 60px #ccc;}

a div:first-of-type span {left:-20px;}
a div:first-of-type span:first-child {top:-20px;}
a div:first-of-type span:last-child {bottom:-20px;}

a div:last-of-type span {right:-20px;}
a div:last-of-type span:first-child {top:-20px;}
a div:last-of-type span:last-child {bottom:-20px;}

<a href="">
    <div>
        <span></span>
        <span></span>
    </div>

    <div>
        <span></span>
        <span></span>
    </div>
</a>

Answer 3

我不认为如果角落必须是透明的,那么如果背景已知,你可以在每个角落创建一个带圆角边框的div.如果这些div具有与页面背景相同的背景颜色,则效果将起作用.

看看我的例子http://jsfiddle.net/TdDtX/

#box {
    position: relative;
    margin: 30px;
    width: 200px;
    height: 100px;
    background: #ccc;
    border: 1px solid #333;
}

.corner {
    position: absolute;
    height: 10px;
    width: 10px;
    border: 1px solid #333;
    background-color: #fff;
}

.top-left {
    top: -1px;
    left: -1px;
    border-radius: 0 0 100% 0;
    border-width: 0 1px 1px 0;
}

.top-right {
    top: -1px;
    left: 190px;
    border-radius: 0 0 0 100%;
    border-width: 0 0 1px 1px;
}

.bottom-left {
    top: 90px;
    left: -1px;
    border-radius: 0 100% 0 0;
    border-width: 1px 1px 0 0;
}

.bottom-right {
    top: 90px;
    left: 190px;
    border-radius: 100% 0 0 0;
    border-width: 1px 0 0 1px;
}

<div id="box">
    <div class="corner top-left"></div>
    <div class="corner top-right"></div>
    <div class="corner bottom-left"></div>
    <div class="corner bottom-right"></div>
</div>