SVGCircleElement - Web APIs 编辑

The SVGCircleElement interface is an interface for the <circle> element.

  <div id="interfaceDiagram" style="display: inline-block; position: relative; width: 100%; padding-bottom: 20%; vertical-align: middle; overflow: hidden;"><svg style="display: inline-block; position: absolute; top: 0; left: 0;" viewbox="-50 0 700 140" preserveAspectRatio="xMinYMin meet"><a xlink:href="/wiki/en-US/docs/Web/API/EventTarget" target="_top"><rect x="1" y="1" width="110" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="56" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">EventTarget</text></a><polyline points="111,25  121,20  121,30  111,25" stroke="#D4DDE4" fill="none"/><line x1="121" y1="25" x2="151" y2="25" stroke="#D4DDE4"/><a xlink:href="/wiki/en-US/docs/Web/API/Node" target="_top"><rect x="151" y="1" width="75" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="188.5" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">Node</text></a><polyline points="226,25  236,20  236,30  226,25" stroke="#D4DDE4" fill="none"/><line x1="236" y1="25" x2="266" y2="25" stroke="#D4DDE4"/><a xlink:href="/wiki/en-US/docs/Web/API/Element" target="_top"><rect x="266" y="1" width="75" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="303.5" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">Element</text></a><polyline points="341,25  351,20  351,30  341,25" stroke="#D4DDE4" fill="none"/><line x1="351" y1="25" x2="381" y2="25" stroke="#D4DDE4"/><a xlink:href="https://developer.mozilla.org/wiki/en-US/docs/Web/API/SVGElement" target="_top"><rect x="381" y="1" width="100" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="431" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">SVGElement</text></a><polyline points="481,25  491,20  491,30  481,25" stroke="#D4DDE4" fill="none"/><line x1="491" y1="25" x2="499" y2="25" stroke="#D4DDE4"/><line x1="499" y1="25" x2="499" y2="90" stroke="#D4DDE4"/><line x1="499" y1="90" x2="482" y2="90" stroke="#D4DDE4"/><a xlink:href="/wiki/en-US/docs/Web/API/SVGGraphicsElement" target="_top"><rect x="301" y="65" width="180" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="391" y="94" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">SVGGraphicsElement</text></a><polyline points="301,89  291,84  291,94  301,89" stroke="#D4DDE4" fill="none"/><line x1="291" y1="89" x2="261" y2="89" stroke="#D4DDE4"/><a xlink:href="https://developer.mozilla.org/wiki/en-US/docs/Web/API/SVGGeometryElement" target="_top"><rect x="81" y="65" width="180" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text  x="171" y="94" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">SVGGeometryElement</text></a><polyline points="81,89  71,84  71,94  81,89" stroke="#D4DDE4" fill="none"/><line x1="71" y1="89" x2="41" y2="89" stroke="#D4DDE4"/><a xlink:href="/wiki/en-US/docs/Web/API/SVGCircleElement" target="_top"><rect x="-119" y="65" width="160" height="50" fill="#F4F7F8" stroke="#D4DDE4" stroke-width="2px" /><text  x="-39" y="94" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">SVGCircleElement</text></a></svg></div>

  a:hover text { fill: #0095DD; pointer-events: all;}

Properties

This interface also inherits properties from its parent, SVGGeometryElement.

SVGCircleElement.cx Read only

This property defines the x-coordinate of the center of the <circle> element. It is denoted by the cx attribute of the element.

SVGCircleElement.cy Read only

This property defines the y-coordinate of the center of the <circle> element. It is denoted by the cy attribute of the element.

SVGCircleElement.r Read only

This property defines the radius of the <circle> element. It is denoted by the r of the element.

Methods

This interface has no methods but inherits methods from its parent, SVGGeometryElement.

Example

SVG content

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 250 250" width="250" height="250">
  <circle cx="100" cy="100" r="50" fill="gold" id="circle"
      onclick="clickCircle();"/>
</svg>

JavaScript content

This function clickCircle() is called when the circle is clicked. It randomly increases or decreases the radius of the circle element.

function clickCircle() {
  var circle = document.getElementById("circle");
  // Randomly determine if the circle radius will increase or decrease
  var change = Math.random() > 0.5 ? 10 : -10;
  // Clamp the circle radius to a minimum of 10 and a maximum of 250,
  // so it won't disappear or get bigger than the viewport
  var newValue = Math.min(Math.max(circle.r.baseVal.value + change, 10), 250);
  circle.setAttribute("r", newValue);
}

Click on the circle.

Specifications

Browser Compatibility

BCD tables only load in the browser

See also

• <circle> SVG element