Element.scrollHeight

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句法
范例
Problems and solutions
scrollHeight Demo
规范
浏览器兼容性
另请参阅
相关话题

Element.scrollHeight read-only property is a measurement of the height of an element's content, including content not visible on the screen due to overflow.

scrollHeight value is equal to the minimum height the element would require in order to fit all the content in the viewport without using a vertical scrollbar. The height is measured in the same way as clientHeight : it includes the element's padding, but not its border, margin or horizontal scrollbar (if present). It can also include the height of pseudo-elements such as ::before or ::after . If the element's content can fit without a need for vertical scrollbar, its scrollHeight 等于 clientHeight

This property will round the value to an integer. If you need a fractional value, use Element.getBoundingClientRect() .

句法

elemScrollHeight = element.scrollHeight;

值

An integer corresponding to the scrollHeight pixel value of the element.

范例

padding-top

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

padding-bottom

Left Top Right Bottom margin-top margin-bottom border-top border-bottom

Image:scrollHeight.png

Problems and solutions

Determine if an element has been totally scrolled

The following equivalence returns true if an element is at the end of its scroll, false if it isn't.

element.scrollHeight - element.scrollTop === element.clientHeight

When the container does not scroll, but has overflowing children, these checks determine if the container can scroll:

window.getComputedStyle(element).overflowY === 'visible'
window.getComputedStyle(element).overflowY !== 'hidden'

scrollHeight Demo

Associated with the onscroll event, this equivalence can be useful to determine whether a user has read a text or not (see also the element.scrollTop and element.clientHeight properties). For example:

HTML

<form name="registration">
<p>
<textarea id="rules">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum at laoreet magna.
Aliquam erat volutpat. Praesent molestie, dolor ut eleifend aliquam, mi ligula ultrices sapien, quis cursus
neque dui nec risus. Duis tincidunt lobortis purus eu aliquet. Quisque in dignissim magna. Aenean ac lorem at
velit ultrices consequat. Nulla luctus nisi ut libero cursus ultrices. Pellentesque nec dignissim enim. Phasellus
ut quam lacus, sed ultricies diam. Vestibulum convallis rutrum dolor, sit amet egestas velit scelerisque id.
Proin non dignissim nisl. Sed mi odio, ullamcorper eget mattis id, malesuada vitae libero. Integer dolor lorem,
mattis sed dapibus a, faucibus id metus. Duis iaculis dictum pulvinar. In nisi nibh, dapibus ac blandit at, porta
at arcu. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Praesent
dictum ipsum aliquet erat eleifend sit amet sollicitudin felis tempus. Aliquam congue cursus venenatis. Maecenas
luctus pellentesque placerat. Mauris nisl odio, condimentum sed fringilla a, consectetur id ligula. Praesent sem
sem, aliquet non faucibus vitae, iaculis nec elit. Nullam volutpat, lectus et blandit bibendum, nulla lorem congue
turpis, ac pretium tortor sem ut nibh. Donec vel mi in ligula hendrerit sagittis. Donec faucibus viverra fermentum.
Fusce in arcu arcu. Nullam at dignissim massa. Cras nibh est, pretium sit amet faucibus eget, sollicitudin in
ligula. Vivamus vitae urna mauris, eget euismod nunc. Aenean semper gravida enim non feugiat. In hac habitasse
platea dictumst. Cras eleifend nisl volutpat ante condimentum convallis. Donec varius dolor malesuada erat
consequat congue. Donec eu lacus ut sapien venenatis tincidunt. Quisque sit amet tellus et enim bibendum varius et
a orci. Donec aliquet volutpat scelerisque. Proin et tortor dolor. Ut aliquet, dolor a mattis sodales, odio diam
pulvinar sem, egestas pretium magna eros vitae felis. Nam vitae magna lectus, et ornare elit. Morbi feugiat, ipsum
ac mattis congue, quam neque mollis tortor, nec mollis nisl dolor a tortor. Maecenas varius est sit amet elit
interdum quis placerat metus posuere. Duis malesuada justo a diam vestibulum vel aliquam nisi ornare. Integer
laoreet nisi a odio ornare non congue turpis eleifend. Cum sociis natoque penatibus et magnis dis parturient montes,
nascetur ridiculus mus. Cras vulputate libero sed arcu iaculis nec lobortis orci fermentum.
</textarea>
</p>
<p>
<input type="checkbox" id="agree" name="accept" />
<label for="agree">I agree</label>
<input type="submit" id="nextstep" value="Next" />
</p>
</form>

CSS

#notice {
  display: inline-block;
  margin-bottom: 12px;
  border-radius: 5px;
  width: 600px;
  padding: 5px;
  border: 2px #7FDF55 solid;
}
#rules {
  width: 600px;
  height: 130px;
  padding: 5px;
  border: #2A9F00 solid 2px;
  border-radius: 5px;
}

JavaScript

function checkReading () {
  if (checkReading.read) {
    return;
  }
  checkReading.read = this.scrollHeight - this.scrollTop === this.clientHeight;
  document.registration.accept.disabled = document.getElementById("nextstep").disabled = !checkReading.read;
  checkReading.noticeBox.innerHTML = checkReading.read ? "Thank you." : "Please, scroll and read the following text.";
}
onload = function () {
  var oToBeRead = document.getElementById("rules");
  checkReading.noticeBox = document.createElement("span");
  document.registration.accept.checked = false;
  checkReading.noticeBox.id = "notice";
  oToBeRead.parentNode.insertBefore(checkReading.noticeBox, oToBeRead);
  oToBeRead.parentNode.insertBefore(document.createElement("br"), oToBeRead);
  oToBeRead.onscroll = checkReading;
  checkReading.call(oToBeRead);
}

规范

规范	状态	注释
CSSOM (CSS 对象模型) 视图模块 The definition of 'Element.scrollHeight' in that specification.	工作草案	初始定义

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`scrollHeight`	Chrome 4	Edge 12	Firefox 21 21 不支持 3 — 21 In Firefox versions prior to 21, when an element's content does not generate a vertical scrollbar, then its `scrollHeight` property is equal to its `clientHeight` property. This can mean either the content is too short to require a scrollbar or that the element has a CSS style `overflow` value of `visible` (non-scrollable).	IE 5 5 In Internet Explorer 5 through 7, if padding is set, the value of `scrollHeight` is equal to the sum of the top and bottom padding. This behavior was fixed in Internet Explorer 8.	Opera 8	Safari 6	WebView Android ≤37	Chrome Android 18	Firefox Android 21 21 不支持 4 — 21 In Firefox versions prior to 21, when an element's content does not generate a vertical scrollbar, then its `scrollHeight` property is equal to its `clientHeight` property. This can mean either the content is too short to require a scrollbar or that the element has a CSS style `overflow` value of `visible` (non-scrollable).	Opera Android 10.1	Safari iOS 6	Samsung Internet Android 1.0

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句法

值

范例