Element: scroll event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Thuộc tính scroll fires when an element has been scrolled. To detect when scrolling has completed, see the scrollend event of Element.

Cú pháp

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("scroll", (event) => { })

onscroll = (event) => { }

Các giá trị sau examples show how to use the scroll event with an event listener and with the onscroll event handler property. The setTimeout() method is used to throttle the event handler because scroll events can fire at a high rate. For additional examples that use requestAnimationFrame(), see the Document scroll event page.

Sử dụng `scroll` with an event listener

Các giá trị sau example shows how to use the scroll event to detect when the user is scrolling inside an element:

html

<div id="scroll-box">
  <p>Scroll me!</p>
</div>
<p id="output">Waiting on scroll events...</p>

css

#scroll-box {
  overflow: scroll;
  height: 100px;
  width: 100px;
  float: left;
}

#scroll-box p {
  height: 200px;
  width: 200px;
}

#output {
  text-align: center;
}

const element = document.querySelector("div#scroll-box");
const output = document.querySelector("p#output");

element.addEventListener("scroll", (event) => {
  output.textContent = "Scroll event fired!";
  setTimeout(() => {
    output.textContent = "Waiting on scroll events...";
  }, 1000);
});

Sử dụng `onscroll` event handler property

Các giá trị sau example shows how to use the onscroll event handler property to detect when the user is scrolling:

html

<div id="scroll-box">
  <p>Scroll me!</p>
</div>
<p id="output">Waiting on scroll events...</p>

css

#scroll-box {
  overflow: scroll;
  height: 100px;
  width: 100px;
  float: left;
}

#scroll-box p {
  height: 200px;
  width: 200px;
}

#output {
  text-align: center;
}

const element = document.querySelector("div#scroll-box");
const output = document.querySelector("p#output");

element.onscroll = (event) => {
  output.textContent = "Element scroll event fired!";
  setTimeout(() => {
    output.textContent = "Waiting on scroll events...";
  }, 1000);
};