diff options
Diffstat (limited to 'files/zh-cn/web/api/intersectionobserver/observe/index.html')
| -rw-r--r-- | files/zh-cn/web/api/intersectionobserver/observe/index.html | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/files/zh-cn/web/api/intersectionobserver/observe/index.html b/files/zh-cn/web/api/intersectionobserver/observe/index.html new file mode 100644 index 0000000000..fd9f581586 --- /dev/null +++ b/files/zh-cn/web/api/intersectionobserver/observe/index.html @@ -0,0 +1,64 @@ +--- +title: IntersectionObserver.observe() +slug: Web/API/IntersectionObserver/observe +translation_of: Web/API/IntersectionObserver/observe +--- +<div>{{APIRef("Intersection Observer API")}}{{SeeCompatTable}}</div> + +<p><span class="seoSummary">{{domxref("IntersectionObserver")}} 对象的<code><strong>observe()</strong></code> 方法向IntersectionObserver对象监听的目标集合添加一个元素。一个监听者有一组阈值和一个根， 但是可以监视多个目标元素，以查看这些目标元素可见区域的变化。</span>调用{{domxref("IntersectionObserver.unobserve()")}}方法可以停止观察元素。</p> + +<p>当指定元素的可见区域超过监听者的可见区域阈值之一时（阈值列表{{domxref("IntersectionObserver.thresholds")}}），监听者的回调会被传入代表当前发生的交叉变化{{domxref("IntersectionObserverEntry")}}并执行。请注意，这种设计允许通过调用一次回调，给回调传入IntersectionObserverEntry对象数组，来实现同时处理多个被监听元素的交叉变化。</p> + +<h2 id="语法">语法</h2> + +<pre class="syntaxbox"><em>IntersectionObserver</em>.observe(<em>targetElement</em>);</pre> + +<h3 id="参数">参数</h3> + +<dl> + <dt><code>targetElement</code></dt> + <dd>可见性区域被监控的元素{{domxref("element")}}。<br> + 此元素必须是根元素的后代 (如果根元素为视窗，则该元素必须被当前文档包含)。</dd> +</dl> + +<h3 id="返回值">返回值</h3> + +<p><code>undefined</code>.</p> + +<dl> +</dl> + +<h2 id="Examples">Examples</h2> + +<p><<<...>>></p> + +<h2 id="Specifications">Specifications</h2> + +<table class="standard-table"> + <tbody> + <tr> + <th scope="col">Specification</th> + <th scope="col">Status</th> + <th scope="col">Comment</th> + </tr> + <tr> + <td>{{SpecName('IntersectionObserver','#dom-intersectionobserver-observe','IntersectionObserver.observe()')}}</td> + <td>{{Spec2('IntersectionObserver')}}</td> + <td>Initial definition.</td> + </tr> + </tbody> +</table> + +<div> +<h2 id="Browser_compatibility">Browser compatibility</h2> + +<p class="hidden">The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</p> + +<p>{{Compat("api.IntersectionObserver.observe")}}</p> +</div> + +<h2 id="See_also">See also</h2> + +<ul> + <li>{{domxref("IntersectionObserver.unobserve()")}}</li> +</ul> |