Html 带有部分边框的 HTML5 / CSS3 圆

HTML5 / CSS3 Circle with Partial Border

提问by knpwrs

Is it possible to create a circle using only HTML5 / CSS3 which has a border that only goes part way around the circle? If not, what techniques can I use to accomplish this effect? I would prefer to use pure DOM elements, but if I have to I can draw on canvas or spin up an SVG.

是否可以仅使用 HTML5/CSS3 创建一个圆圈，该圆圈的边框仅围绕圆圈的一部分？如果没有，我可以使用哪些技术来实现这种效果？我更喜欢使用纯 DOM 元素，但如果必须的话，我可以在画布上绘制或旋转 SVG。

回答by Ana

Yes, it is possible - see this:

是的，这是可能的 - 看这个：

demo

演示

.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>

回答by gkond

It's possible.

这是可能的。

• Draw two circles using border-radiusone on top of another.
• Make one or more arc of both circles transparentby changing border-color.
• Use transformto rotate the second circle and you will have the arc of the size you need.

• 使用border-radius一个在另一个之上绘制两个圆圈。
• transparent通过更改来制作两个圆的一个或多个圆弧border-color。
• 使用transform旋转第二个圆，您将获得所需大小的圆弧。

Here is the demo: http://jsfiddle.net/kJXwZ/2/

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>

回答by will

This uses JavaScript as well, so it breaks from the original requirement :(
.. it does however deliver

这也使用了 JavaScript，所以它打破了最初的要求 :(
.. 然而它确实提供了

There is a >> demo<< here

有一个 >>演示<< 这里

@gkond Thanks, I derived this from your answer

@gkond 谢谢，我是从你的回答中得出的

// 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 funciton 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;
}

<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>

回答by mark stewart

To do this, you can use simple box border properties, one element and one class. This would be an inline, inline-block or block treatment, depending on where you place your easy-circle class, and how/if you style position.

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，以及如何/是否设置样式位置。

<!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>

回答by seanculleng

This can be achieved setting a transparent border around a transparent circle and using border-top-color: ;to give a section of the circles border a color.

这可以通过在透明圆圈周围设置透明边框并使用border-top-color: ;给圆圈边框的一部分颜色来实现。

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

This creates a circle with a border only around the top quarter;

这将创建一个仅在顶部四分之一周围有边框的圆圈；

You can also use

你也可以使用

border-bottom-color:green;

as well as left and right to border different quarters of the circles circumference.

以及向左和向右边界圆圆周的不同四分之一。

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

这是一个带有 3 个部分圆圈的装载机的小提琴，它们以交替的方向在彼此内部旋转，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.

这是一个带有 3 个部分圆圈的装载机的小提琴，它们以交替的方向在彼此内部旋转，显示了这一点。

回答by Nicola Mihaita

Simplest way to animate this is using css keyframes.

制作动画的最简单方法是使用 css 关键帧。

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

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>