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The onwheel property of the GlobalEventHandlers mixin is an EventHandler that processes wheel events.

The wheel event fires when the user rotates the mouse (or other pointing device) wheel.

Note: Don't confuse onwheel with onscroll: onwheel handles general wheel rotation, while onscroll handles scrolling of an object's content.

Syntax

target.onwheel = functionRef;

Value

functionRef is a function name or a function expression. The function receives a WheelEvent object as its sole argument.

Examples

This example shows how to scale an element using the mouse (or other pointing device) wheel.

HTML

<div>Scale me with your mouse wheel.</div>

CSS

body {
  min-height: 100vh;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

div {
  width: 105px;
  height: 105px;
  background: #cdf;
  padding: 5px;
}

JavaScript

function zoom(event) {
  event.preventDefault();

  if (event.deltaY < 0) {
    // Zoom in
    scale *= event.deltaY * -2;
  }
  else {
    // Zoom out
    scale /= event.deltaY * 2;
  }

  // Restrict scale
  scale = Math.min(Math.max(.125, scale), 4);

  // Apply scale transform
  el.style.transform = `scale(${scale})`;
}

let scale = 1;
const el = document.querySelector('div');
window.onwheel = zoom;

Result

Specification

Specification Status Comment
HTML Living Standard
The definition of 'onwheel' in that specification.
Living Standard  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
onwheelChrome Full support 61Edge Full support YesFirefox Full support YesIE Full support YesOpera Full support 48Safari Full support YesWebView Android Full support 61Chrome Android Full support 61Edge Mobile Full support YesFirefox Android Full support YesOpera Android Full support 48Safari iOS Full support YesSamsung Internet Android ?

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

See also

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最終更新者: irenesmith,