How to draw circle in html page?

问题

How do you draw a circle using HTML5 and CSS3?

Is it also possible to put text inside?

回答1:

You can't draw a circle per se. But you can make something identical to a circle.

You'd have to create a rectangle with rounded corners (via border-radius) that are one-half the width/height of the circle you want to make.

    #circle {
      width: 50px;
      height: 50px;
      -webkit-border-radius: 25px;
      -moz-border-radius: 25px;
      border-radius: 25px;
      background: red;
    }

<div id="circle"></div>

回答2:

It is quite possible in HTML 5. Your options are: Embedded SVG and <canvas> tag.

To draw circle in embedded SVG:

<svg xmlns="http://www.w3.org/2000/svg">
    <circle cx="50" cy="50" r="50" fill="red" />
</svg>

Circle in <canvas>:

var canvas = document.getElementById("circlecanvas");
var context = canvas.getContext("2d");
context.arc(50, 50, 50, 0, Math.PI * 2, false);
context.fillStyle = "red";
context.fill()

<canvas id="circlecanvas" width="100" height="100"></canvas>

回答3:

There are a few unicode circles you could use:

* { font-size: 50px; }

&#x25CB;
&#x25CC;
&#x25CD;
&#x25CE;
&#x25CF;

More shapes here.

You can overlay text on the circles if you want to:

#container {
    position: relative;
}
#circle {
  font-size: 50px;
  color: #58f;
}
#text {
    z-index: 1;
    position: absolute;
    top: 21px;
    left: 11px;
}

<div id="container">
    <div id="circle">&#x25CF;</div>
    <div id="text">a</div>
</div>

You could also use a custom font (like this one) if you want to have a higher chance of it looking the same on different systems since not all computers/browsers have the same fonts installed.

回答4:

border-radius:50% if you want the circle to adjust to whatever dimensions the container gets (e.g. if the text is variable length)

Don't forget the -moz- and -webkit- prefixes!

回答5:

As of 2015, you can make it and center the text with as few as 15 lines of CSS (Fiddle):

body {
  background-color: #fff;
}
#circle {
  position: relative;
  background-color: #09f;
  margin: 20px auto;
  width: 400px;
  height: 400px;
  border-radius: 200px;
}
#text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: #fff;
}

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>circle with text</title>

</head>

<body>
  <div id="circle">
    <div id="text">Text in the circle</div>
  </div>
</body>

</html>

Without any -webkit-s, this works on IE11, Firefox, Chrome and Opera, on Windows7, and it is valid HTML5 (experimental) and CSS3.

回答6:

You can use the border-radius attribute to give it a border-radius equivalent to the element's border-radius. For example:

<div style="border-radius 10px; -moz-border-radius 10px; -webkit-border-radius 10px; width: 20px; height: 20px; background: red; border: solid black 1px;">&nbsp;</div>

(The reason for using the -moz and -webkit extensions is to support pre-CSS3-final versions of Gecko and Webkit.)

There are more examples on this page. As far as inserting text, you can do it but you have to be mindful of the positioning, as most browsers' box padding model still uses the outer square.

回答7:

There is not technically a way to draw a circle with HTML (there isn’t a <circle> HTML tag), but a circle can be drawn.

The best way to draw one is to add border-radius: 50% to a tag such as div. Here’s an example:

<div style="width: 50px; height: 50px; border-radius: 50%;">You can put text in here.....</div>

回答8:

.circle{
    height: 65px;
    width: 65px;
    border-radius: 50%;
    border:1px solid red;
    line-height: 65px;
    text-align: center;
}

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

回答9:

border-radius: 50%; will turn all elements into a circle, regardless of size. At least, as long as the height and width of the target are the same, otherwise it will turn into an oval.

#target{
    width: 100px;
    height: 100px;
    background-color: #aaa;
    border-radius: 50%;
}

<div id="target"></div>

Note: browser prefixes are not needed anymore for border-radius

Alternatively, you can use clip-path: circle(); to turn an element into a circle as well. Even if the element has a greater width than height (or the other way around), it will still become a circle, and not an oval.

#target{
    width: 200px;
    height: 100px;
    background-color: #aaa;
    clip-path: circle();
}

<div id="target"></div>

In fact, you can use clip-path to turn elements into all kinds of shapes

Note: clip-path is not (yet) supported by all browsers

You can place text inside of the circle, simply by writing the text inside of the tags of the target,
like so:

<div>text</div>

If you want to center text in the circle, you can do the following:

#target{
    width: 100px;
    height: 100px;
    background-color: #aaa;
    border-radius: 50%;

    display: flex;
    align-items: center;
}

#text{
    width: 100%;
    text-align: center;
}

<div id="target">
    <div id="text">text</div>
</div>

回答10:

You can use border-radius property, or make a div with fixed height and width and a background with png circle.

回答11:

Simply do the following in the script tags:

<!Doctype html>
<html>
<head>
	<title>Circle Canvas</title>
</head>
<body>
	<canvas id="myCanvas" width="300" height="150" style="border:1px solid 
#d3d3d3;">
	<body>
		<script>
			var c = document.getElementById("myCanvas");
			var ctx = c.getContext("2d");
			ctx.beginPath();
			ctx.arc(100, 75, 50, 0, 2 * Math.PI);
			ctx.stroke();
		</script>
    </body>
</body>
</html>

And there you go you got your circle.

回答12:

h1 {
border: dashed 2px blue;
  width: 200px;
  height: 200px;
  border-radius: 100px;
  text-align: center;
  line-height: 60px;
  
}

<h1> <br>hello world</h1>

回答13:

.at-counter-box {
    border: 2px solid #1ac6ff;
    width: 150px;
    height: 150px;
    border-radius: 100px;
    font-family: 'Oswald Sans', sans-serif;
    color:#000;
}
.at-counter-box-content {
    position: relative;
}
.at-counter-content span {
    font-size: 40px;
    font-weight: bold ;
    text-align: center;
    position: relative;
    top: 55px;
}

回答14:

   <head>
       <style>

       #circle{
       width:200px;
       height:200px;
       border-radius:100px;
       background-color:red;
       }
       </style>
   </head>

    <body>
       <div id="circle"></div>
   </body>

simple and novice :)

回答15:

<div class="at-counter-box-content">

  <div class="at-counter-content">

      <span>40%</span>

  </div><!--at-counter-content-->

</div><!--at-counter-box-content-->

回答16:

If you're using sass to write your CSS you can do:

@mixin draw_circle($radius){
  width: $radius*2;
  height: $radius*2;
  -webkit-border-radius: $radius;
  -moz-border-radius: $radius;
  border-radius: $radius;
}

.my-circle {
  @include draw_circle(25px);
  background-color: red;
}

Which outputs:

.my-circle {
  width: 50px;
  height: 50px;
  -webkit-border-radius: 25px;
  -moz-border-radius: 25px;
  border-radius: 25px;
  background-color: red;
}

Try it here: https://www.sassmeister.com/

来源：https://stackoverflow.com/questions/6921792/how-to-draw-circle-in-html-page

标签

html

css

css3

geometry

css-shapes