CSS 3 形状：“反圆”或“切出圆”
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原文地址: http://stackoverflow.com/questions/10501488/
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CSS 3 Shape: "Inverse Circle" or "Cut Out Circle"
提问by Alp
I want to create a shape, which i would describe as "inverse circle":
我想创建一个形状，我将其描述为“反圆”：
The image is somehow inaccurate, because the black line should continue along the outer border of the div element.
图像在某种程度上不准确，因为黑线应该沿着 div 元素的外边框继续。
Here is a demo of what i have at the moment: http://jsfiddle.net/n9fTF/
这是我目前所拥有的演示：http: //jsfiddle.net/n9fTF/
Is that even possible with CSSwithout images?
CSS没有图像甚至可能吗？
回答by ScottS
Update: CSS3 Radial Background Gradient Option
更新：CSS3 径向背景渐变选项
(For those browsers supporting it--tested in FF and Chrome--IE10, Safari should work too).
（对于那些支持它的浏览器——在 FF 和 Chrome 中测试——IE10，Safari 也应该可以工作）。
One "problem" with my original answer is those situations where one does not have a solid background that they are working against. This update creates the same effect allowing for a transparent "gap" between the circle and it's inverse cutout.
我最初的答案的一个“问题”是那些没有坚实背景的情况。此更新创建了相同的效果，允许在圆和它的反向切口之间形成透明的“间隙”。
See example fiddle.
请参阅示例小提琴。
CSS
CSS
.inversePair {
border: 1px solid black;
display: inline-block;
position: relative;
height: 100px;
text-align: center;
line-height: 100px;
vertical-align: middle;
}
#a {
width: 100px;
border-radius: 50px;
background: grey;
z-index: 1;
}
#b {
width: 200px;
/* need to play with margin/padding adjustment
based on your desired "gap" */
padding-left: 30px;
margin-left: -30px;
/* real borders */
border-left: none;
-webkit-border-top-right-radius: 20px;
-webkit-border-bottom-right-radius: 20px;
-moz-border-radius-topright: 20px;
-moz-border-radius-bottomright: 20px;
border-top-right-radius: 20px;
border-bottom-right-radius: 20px;
/* the inverse circle "cut" */
background-image: -moz-radial-gradient(
-23px 50%, /* the -23px left position varies by your "gap" */
circle closest-corner, /* keep radius to half height */
transparent 0, /* transparent at center */
transparent 55px, /*transparent at edge of gap */
black 56px, /* start circle "border" */
grey 57px /* end circle border and begin color of rest of background */
);
background-image: -webkit-radial-gradient(-23px 50%, circle closest-corner, rgba(0, 0, 0, 0) 0, rgba(0, 0, 0, 0) 55px, black 56px, grey 57px);
background-image: -ms-radial-gradient(-23px 50%, circle closest-corner, rgba(0, 0, 0, 0) 0, rgba(0, 0, 0, 0) 55px, black 56px, grey 57px);
background-image: -o-radial-gradient(-23px 50%, circle closest-corner, rgba(0, 0, 0, 0) 0, rgba(0, 0, 0, 0) 55px, black 56px, grey 57px);
background-image: radial-gradient(-23px 50%, circle closest-corner, rgba(0, 0, 0, 0) 0, rgba(0, 0, 0, 0) 55px, black 56px, grey 57px);
}
Original Answer
原答案
Took more effort than I expected to get the z-indexing to work (this seems to ignore the negative z-index), however, this gives a nice clean look(tested in IE9, FF, Chrome):
比我预期的更努力让 z-indexing 工作（这似乎忽略了负 z-index），但是，这提供了一个漂亮干净的外观（在 IE9、FF、Chrome 中测试）：
HTML
HTML
<div id="a" class="inversePair">A</div>
<div id="b" class="inversePair">B</div>
CSS
CSS
.inversePair {
border: 1px solid black;
background: grey;
display: inline-block;
position: relative;
height: 100px;
text-align: center;
line-height: 100px;
vertical-align: middle;
}
#a {
width: 100px;
border-radius: 50px;
}
#a:before {
content:' ';
left: -6px;
top: -6px;
position: absolute;
z-index: -1;
width: 112px; /* 5px gap */
height: 112px;
border-radius: 56px;
background-color: white;
}
#b {
width: 200px;
z-index: -2;
padding-left: 50px;
margin-left: -55px;
overflow: hidden;
-webkit-border-top-right-radius: 20px;
-webkit-border-bottom-right-radius: 20px;
-moz-border-radius-topright: 20px;
-moz-border-radius-bottomright: 20px;
border-top-right-radius: 20px;
border-bottom-right-radius: 20px;
}
#b:before {
content:' ';
left: -58px;
top: -7px;
position: absolute;
width: 114px; /* 5px gap, 1px border */
height: 114px;
border-radius: 57px;
background-color: black;
}
回答by Chris Fletcher
I can't really tell from your drawing how rounded you want the points, but here's one possibility: http://jsfiddle.net/n9fTF/6/
我真的无法从你的画中看出你想要分数有多圆，但这是一种可能性：http: //jsfiddle.net/n9fTF/6/
If the points need to be more rounded, you'll need to put some circles on the ends so they blend with the big scoop.
如果点需要更圆，你需要在末端放一些圆圈，以便它们与大勺混合。
回答by web-tiki
Different approach : Box-shadows
不同的方法：盒阴影
This approach uses CSS box shadows which are supported by IE9+(canIuse)
这种方法使用了 IE9+( canIuse)支持的CSS 框阴影
Output :
输出 ：
HTML :
HTML :
<div id="a">
<div id="b"></div>
</div>
CSS :
CSS :
#a{
overflow:hidden;
border-radius:20px;
position:relative;
display:inline-block;
}
#a:before, #a:after{
content:'';
width: 100px;
border-radius: 50%;
}
#a:before {
height: 100px;
float:left;
border: 1px solid black;
background: grey;
}
#a:after {
position:absolute;
left:14px; top:-6px;
height:114px;
box-shadow: 1px 0px 0px 0px #000, 110px 0px 0px 68px #808080;
background:none;
z-index:-1;
}
#b {
width: 200px;
height: 100px;
background:none;
margin-left:-15px;
border: 1px solid black;
border-left:none;
float:left;
border-top-right-radius: 20px;
border-bottom-right-radius: 20px;
}
回答by Jon Mifsud
This is a very interesting question. I've recently posted a tutorial on how to make Inverse Border Radius in CSS (here)and I think this could easily be adapted for your case.
这是一个非常有趣的问题。我最近发布了一个关于如何在 CSS 中制作反向边框半径的教程（这里），我认为这可以很容易地适应您的情况。
The trick is to create a span that generates the inverse border using a very simple concept - very thick borders. And use the inside section by hiding them. What you would have to do in addition to my script provided is add another border-radius to the top-left corner as I am only using the top-right one. Make the span aligned to the left of the item you want by absolute positioning, and increase the height/width of span accordingly and voila you have your inverse border-radius.
诀窍是使用一个非常简单的概念创建一个生成反向边界的跨度 - 非常粗的边界。并通过隐藏它们来使用内部部分。除了我提供的脚本之外，您还需要在左上角添加另一个边框半径，因为我只使用右上角的边框。通过绝对定位使跨度与您想要的项目的左侧对齐，并相应地增加跨度的高度/宽度，瞧你有你的反向边界半径。
回答by karim79
Introduce an absolutely positioned borderless white circle which sits behind the gray circle at an offset. You will need to set the z-index of the dark circle to ensure that it sits above the white circle:
引入一个绝对定位的无边界白色圆圈，它位于灰色圆圈后面的偏移处。您需要设置黑圈的 z-index 以确保它位于白圈上方：
#c {
position: absolute;
border: 0;
left: 30px;
width: 100px;
height: 100px;
border-radius: 50px;
background: white;
}
演示。?
回答by Rick Donohoe
Someone else done it somewhere from what I found...
其他人从我发现的某处完成了...
JSFiddle: http://jsfiddle.net/ajeN7/
JSFiddle：http: //jsfiddle.net/ajeN7/
and the question: CSS3 Inverted Rounded Corner
和问题：CSS3 倒圆角
Hopefully that helps!
希望这有帮助！
