在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 相关话题

这是 实验性技术
检查 浏览器兼容性表格 要小心谨慎在生产中使用这之前。

contentBoxSize 只读特性在 ResizeObserverEntry interface returns an array containing the new content box size of the observed element when the callback is run.

句法

var myContentBoxSize = ResizeObserverEntry.contentBoxSize;
					

值

An object containing the new content box size of the observed element. This object contains two properties:

blockSize

The length of the observed element's content box in the block dimension. For boxes with a horizontal writing-mode , this is the vertical dimension, or height; if the writing-mode is vertical, this is the horizontal dimension, or width.

inlineSize

The length of the observed element's content box in the inline dimension. For boxes with a horizontal writing-mode , this is the horizontal dimension, or width; if the writing-mode is vertical, this is the vertical dimension, or height.

注意 : For more explanation of writing modes and block and inline dimensions, read Handling different text directions .

范例

The following snippet is taken from the resize-observer-border-radius.html ( see source ) example. This example includes a green box, sized as a percentage of the viewport size. When the viewport size is changed, the box's rounded corners change in proportion to the size of the box. We could just implement this using border-radius with a percentage, but that quickly leads to ugly-looking elliptical corners; this solution gives you nice square corners that scale with the box size.

const resizeObserver = new ResizeObserver(entries => {
  for (let entry of entries) {
    if(entry.contentBoxSize) {
      entry.target.style.borderRadius = Math.min(100, (entry.contentBoxSize.inlineSize/10) +
                                                      (entry.contentBoxSize.blockSize/10)) + 'px';
    } else {
      entry.target.style.borderRadius = Math.min(100, (entry.contentRect.width/10) +
                                                      (entry.contentRect.height/10)) + 'px';
    }
  }
});
resizeObserver.observe(document.querySelector('div'));
					

规范

规范	状态	注释
重置大小观测器 The definition of 'target' in that specification.	编者草案	初始定义。

浏览器兼容性

The compatibility table in 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
contentBoxSize	Chrome No	Edge No	Firefox 69	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android No	Opera Android No	Safari iOS No	Samsung Internet Android No

图例

完整支持

完整支持

不支持

不支持

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

元数据

• 最后修改： Aug 20, 2020

相关话题

1. 重置尺寸观测器 API
2. ResizeObserverEntry
3. 特性

   1. borderBoxSize
   2. contentBoxSize
   3. contentRect
   4. target
4. Related pages for Resize Observer API

   1. ResizeObserver