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• 句法
• 范例
• 规范
• 浏览器兼容性
• 相关话题

target 只读特性在 ResizeObserverEntry interface returns a reference to the 元素 or SVGElement that is being observed.

句法

var element = ResizeObserverEntry.target;
var svgElement = ResizeObserverEntry.target;
					

值

元素 or SVGElement representing the element being observed.

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.

To grab a reference to the observed element so we can update its border-radius value after each change, we make use of the target property of each entry — entry.target.style.borderRadius .

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
target	Chrome 64	Edge 79	Firefox 69	IE No	Opera Yes	Safari No	WebView Android 64	Chrome Android 64	Firefox Android No	Opera Android Yes	Safari iOS No	Samsung Internet Android 9.0

图例

完整支持

完整支持

不支持

不支持

元数据

• 最后修改： Aug 29, 2019

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