Window.scrollX | Web API

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句法
范例
注意事项
规范
浏览器兼容性
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只读 scrollX 特性为 Window interface returns the number of pixels that the document is currently scrolled horizontally. This value is subpixel precise in modern browsers, meaning that it isn't necessarily a whole number. You can get the number of pixels the document is scrolled vertically from the scrollY 特性。

句法

var x = window.scrollX;

值

In practice, the returned value is a double-precision floating-point value indicating the number of pixels the document is currently scrolled horizontally from the origin, where a positive value means the content is scrolled to the left. If the document is rendered on a subpixel-precise device, then the returned value is also subpixel-precise and may contain a decimal component. If the document isn't scrolled at all left or right, then scrollX 为 0。

If you need an integer value, you can use Math.round() to round it off.

In more technical terms, scrollX returns the X coordinate of the left edge of the current viewport . If there is no viewport, the returned value is 0.

范例

This example checks the current horizontal scroll position of the document. If it's greater than 400 pixels, the window is scrolled back to the beginning.

if (window.scrollX > 400) {
  window.scroll(0,0);
}

注意事项

pageXOffset property is an alias for the scrollX 特性：

window.pageXOffset == window.scrollX; // always true

For cross-browser compatibility, use window.pageXOffset 而不是 window.scrollX . Additionally , older versions of Internet Explorer (< 9) do not support either property and must be worked around by checking other non-standard properties. A fully compatible example:

var x = (window.pageXOffset !== undefined)
  ? window.pageXOffset
  : (document.documentElement || document.body.parentNode || document.body).scrollLeft;
var y = (window.pageYOffset !== undefined)
  ? window.pageYOffset
  : (document.documentElement || document.body.parentNode || document.body).scrollTop;

规范

规范	状态	注释
CSSOM (CSS 对象模型) 视图模块 The definition of 'window.scrollX' in that specification.	工作草案

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
`scrollX`	Chrome Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Edge ≤18 ≤18 12 Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Firefox Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	IE No 不支持 No 9 Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Opera Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Safari Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	WebView Android Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Chrome Android Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Firefox Android Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Opera Android Yes Yes ? Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Safari iOS Yes Yes ? Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`	Samsung Internet Android Yes Yes Yes Alternate Name Alternate Name Uses the non-standard name: `pageXOffset`
Subpixel precision	Chrome Yes	Edge ≤18	Firefox 55	IE No	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 55	Opera Android ?	Safari iOS ?	Samsung Internet Android Yes

图例

完整支持
不支持
兼容性未知 ?

另请参阅

Window.scrollY

元数据

最后修改： 2019 年 3 月 23 日

在此页

句法

值

范例

注意事项

规范

浏览器兼容性

图例

另请参阅

相关话题