HTML5 / CSS3 带部分边框的圆圈

Question

是否可以仅使用 HTML5 / CSS3 创建一个圆形，该圆形的边框仅围绕圆形的一部分？如果不是，我可以使用什么技术来实现这种效果？我更喜欢使用纯 DOM 元素，但如果必须，我可以在画布上绘制或启动 SVG。

Answer 1

是的，有可能 - 请参阅：

demo

.circle {
  position: relative;
  margin: 7em auto;
  width: 16em;
  height: 16em;
  border-radius: 50%;
  background: lightblue;
}

.arc {
  overflow: hidden;
  position: absolute;
  /* make sure top & left values are - the width of the border */
  /* the bottom right corner is the centre of the parent circle */
  top: -1em;
  right: 50%;
  bottom: 50%;
  left: -1em;
  /* the transform origin is the bottom right corner */
  transform-origin: 100% 100%;
  /* rotate by any angle */
  /* the skew angle is 90deg - the angle you want for the arc */
  transform: rotate(45deg) skewX(30deg);
}

.arc:before {
  box-sizing: border-box;
  display: block;
  border: solid 1em navy;
  width: 200%;
  height: 200%;
  border-radius: 50%;
  transform: skewX(-30deg);
  content: '';
}

<div class='circle'>
  <div class='arc'></div>
</div>

Answer 2

这是可能的。

• 使用border-radius 绘制两个圆，一个在另一个之上。
• 通过更改 border-color 来创建两个圆 transparent 的一个或多个弧。
• 使用transform 旋转第二个圆，您将获得所需大小的圆弧。

这是演示：http://jsfiddle.net/kJXwZ/2/

.wrapper {
  position: relative;
  margin: 20px;
}

.arc {
  position: absolute;
  top: 0;
  left: 0;
  width: 100px;
  height: 100px;
  border-radius: 100%;
  border: 1px solid;
}

.arc_start {
  border-color: transparent red red red;
  -webkit-transform: rotate(45deg);
  -moz-transform: rotate(45deg);
  -ms-transform: rotate(45deg);
  -o-transform: rotate(45deg);
  transform: rotate(45deg);
}

.arc_end {
  border-color: red red red transparent;
  -webkit-transform: rotate(75deg);
  -moz-transform: rotate(75deg);
  -ms-transform: rotate(75deg);
  -o-transform: rotate(75deg);
  transform: rotate(75deg);
}

<div class="wrapper">
  <div class="arc arc_start"></div>
  <div class="arc arc_end"></div>
</div>

Answer 3

这也使用了 JavaScript，因此它打破了最初的要求 :(
..它确实提供了

有一个>>demo

@gkond 谢谢，我从你的回答中得出了这个

// create a circle using HTML5 / CSS3 / JS which has a border that only goes part-way around
// the circle .. and which can be smoothly animated from 0% to 100% around the circle

// this solution allows for animation and still results in relatively clean code
// we use four quarter-circles, all hidden away behind a white square to start with..
// all four are rotated out clockwise, and each quarter will stop at it's own maximum:
// q1 at 25%, q2 at 50% .. etc. once we reach a value at or over 25%, all four quarters
// should be out from behind the white square, and we can hide it.. it needs to be
// hidden if we display a value over 75%, or else q4 will end up going in behind it again
// .. also, since the top border will usually sit between the angles of  -45 to 45, we
// rotate everything by an extra -45 to make it all line up with the top nicely

var fromHidden = -90;

// utility function to align 0 degrees with top
// takes degrees and returns degrees - 45
function topAlign(degrees) {
  return degrees - 45
};

// utility function to rotate a jQuery element
// takes element and the degree of rotation (from the top) 
function rotate(el, degrees) {
  var degrees = topAlign(degrees || 0);
  el.css(
    'transform', 'rotate(' + degrees + 'deg)',
    '-webkit-transform', 'rotate(' + degrees + 'deg)',
    '-moz-transform', 'rotate(' + degrees + 'deg)',
    '-ms-transform', 'rotate(' + degrees + 'deg)',
    '-o-transform', 'rotate(' + degrees + 'deg)'
  )
}

// function to draw semi-circle
// takes a jQuery element and a value (between 0 and 1)
// element must contain four .arc_q elements
function circle(el, normalisedValue) {
  var degrees = normalisedValue * 360; // turn normalised value into degrees
  var counter = 1; // keeps track of which quarter we're working with
  el.find('.arc_q').each(function() { // loop over quarters..
    var angle = Math.min(counter * 90, degrees); // limit angle to maximum allowed for this quarter
    rotate($(this), fromHidden + angle); // rotate from the hiding place
    counter++; // track which quarter we'll be working with in next pass over loop
  });
  if (degrees > 90) { // hide the cover-up square soon as we can
    el.find('.arc_cover').css('display', 'none');
  }
}

// uses the the circle function to 'animate' drawing of the semi-circle
// incrementally increses the value passed by 0.01 up to the value required
function animate(el, normalisedValue, current) {
  var current = current || 0;
  circle(el, current);
  if (current < normalisedValue) {
    current += 0.01;
    setTimeout(function() {
      animate(el, normalisedValue, current);
    }, 1);
  }
}

// kick things off ..
animate($('.circle'), 0.69);

.circle {
  position: relative;
  margin: 20px;
  width: 120px;
  height: 120px;
}

.arc_q {
  position: absolute;
  top: 0;
  left: 0;
  width: 100px;
  height: 100px;
  border-radius: 50%;
  border: 10px solid;
  border-color: transparent green transparent transparent;
  transform: rotate(-45deg);
  -webkit-transform: rotate(-45deg);
  -moz-transform: rotate(-45deg);
  -ms-transform: rotate(-45deg);
  -o-transform: rotate(-45deg);
}

.arc_cover {
  position: absolute;
  top: 0;
  left: 0;
  width: 60px;
  height: 60px;
  background-color: white;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="circle">
  <div class="arc_q"></div>
  <div class="arc_q"></div>
  <div class="arc_q"></div>
  <div class="arc_q"></div>
  <div class="arc_cover"></div>
</div>

Answer 4

为此，您可以使用简单的框边框属性，一个元素和一个类。这将是内联、内联块或块处理，具体取决于您放置 easy-circle 类的位置，以及您如何/是否设置位置样式。

<!DOCTYPE html>
<html>
<head>
<style>
.easy-circle {
    background: transparent;
    border: 1em solid black; /* color not required, may show device fail */
    border-color: red green blue transparent;
    height: 10em;
    width: 10em;
    -moz-border-radius: 6em; /* height/2 + border thickness */
    -webkit-border-radius: 6em;
    border-radius: 50%; /* more than 50, shape-size adjustment irrelevant */
    -ms-transform: rotate(45deg); /* IE 9 */
    -webkit-transform: rotate(45deg); /* Chrome, Safari, Opera */
     transform: rotate(45deg); /* transform optional */
}
</style>
</head>
<body>
<div class="easy-circle">
</div>​
</body>
</html>

Answer 5

最简单的动画方法是使用 css 关键帧。

http://jsfiddle.net/8SUPX/644/

/**
 * HTML5 / CSS3 Circle with Partial Border
 * http://stackoverflow.com/q/13059190/1397351
 */
* { margin: 0; padding: 0; }
.circle {
	position: relative;
	margin: 6em auto;
	width: 12em; height: 12em;
	border-radius: 50%;
	background: transparent;
	border:20px solid #efefef;
	border-top-color: #efefef;
    border-right-color: #efefef;
    border-bottom-color: #efefef;
    border-left-color: #efefef;
    
    -webkit-transition:.5s;-moz-transition:.5s;transition:.5s;
}
.circle:hover{
      -webkit-animation:  animix 0.5s 1;
      -webkit-animation-fill-mode: forwards;
      -moz-animation:  animix 0.5s 1;
      -moz-animation-fill-mode: forwards;
      animation:  animix 0.5s 1;
      animation-fill-mode: forwards;
}



  //Animate
   @-webkit-keyframes animix {
    0% { 
      border-top-color: transparent;
      border-right-color: transparent;
      border-bottom-color: transparent;
      border-left-color: transparent;
    }
     25% { 
       border-top-color: red;
       border-right-color: transparent;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     50% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     75% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: transparent;
     }
     100% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: red;
     }
   }
   
      @keyframes animix {
    0% { 
      border-top-color: transparent;
      border-right-color: transparent;
      border-bottom-color: transparent;
      border-left-color: transparent;
    }
     25% { 
       border-top-color: red;
       border-right-color: transparent;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     50% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: transparent;
       border-left-color: transparent;
     }
     75% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: transparent;
     }
     100% { 
       border-top-color: red;
       border-right-color: red;
       border-bottom-color: red;
       border-left-color: red;
     }
   }

<div class="circle"> </div>

Answer 6

这可以通过在透明圆圈周围设置透明边框并使用border-top-color: ; 为圆形边框的一部分赋予颜色来实现。

background-color:transparent;
border:3px solid transparent;
border-top-color: green;

这会创建一个仅在上四分之一周围有边框的圆圈；

你也可以使用

border-bottom-color:green;

以及左右边界的圆圈圆周的不同季度。

这是一个用于加载器的小提琴，它具有 3 个部分圆圈，这些圆圈在彼此内部以交替方向旋转，显示了这一点。

Here's a fiddle for a loader with 3 partial circles that spin inside each other in alternate directions that show this in action.

Answer 7

圆锥梯度解（适用于任何度数）：

:root{
--degree:80deg;
--color:red;
}

.a{
  height:200px;
  width:200px;
border-radius:50%;
background: conic-gradient(
     var(--color) var(--degree), transparent calc(var(--degree) + 0.5deg) 100%);

}

.b{
  height:84%;
  width:84%;
  top:8%;
  left:8%;
  position:relative;
  border-radius:50%;
  background:#D3D3D3;
}

<div class ="a">
    <div class="b">
</div>

Answer 8

如果你想要双边框，你也可以使用它

div
{
  background-color: #ddd;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 30px;
  margin:  40px auto;
  color: black; 
  width: 200px;
  height: 200px; 
  border-radius: 50%; 
  position: relative;
}

div::before
{ 
  content: "";
  width: 200px;
  height: 200px;
  border-radius: 50%;
  position: absolute;
  left: 0;
  top: 0;
  transform: translate(-10px, -10px);
  z-index: -1;
  border: 10px solid;
  border-color: red red red transparent;
}
body ::after
{
  content: "";
  width: 220px;
  height: 220px;
  border-radius: 50%;
  position: absolute;
  left: 0;
  top: 0;
  transform: translate(-21px, -22px);
  z-index: -8;
  border: 12px solid;
  background: transparent;
  border-color: blue transparent blue blue;
}

<div> </div>