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---
title: PerformancePaintTiming
slug: Web/API/PerformancePaintTiming
tags:
- API
- Interface
- Paint Timing
- Performance Timeline API
- PerformancePaintTiming
- Web Performance
- 渲染时机
- 渲染监测
translation_of: Web/API/PerformancePaintTiming
---
<p>{{SeeCompatTable}}{{APIRef("Performance Timeline API")}}</p>
<p><a href="/en-US/docs/Web/API/Paint Timing">Paint Timing</a> 提供的<strong><code>PerformancePaintTiming</code></strong>是一个提供页面在构建过程中的“绘制”（也称“渲染”）时间点信息的接口。“绘制”是指将渲染树转换为页面上像素的过程。</p>
<p>应用可以为名为“<code>paint</code>”的{{domxref("PerformanceEntry","performance entry 类型")}} 注册一个{{domxref("PerformanceObserver")}}，然后观察者可以获取绘制相关的事件发生的时间。以此来帮你找出那些花费太多时间去绘制的区域，而后提升用户体验。</p>
<p>{{InheritanceDiagram}}</p>
<h2 id="属性">属性</h2>
<p>这个接口没有属性，但是（为了"<code>paint</code>" {{domxref ("PerformanceEntry.entryType","performance entry 类型")}}）通过一些限制和约束 扩展了以下{{domxref("PerformanceEntry")}}属性</p>
<dl>
<dt>{{domxref("PerformanceEntry.entryType")}}</dt>
<dd>返回 "<code>paint</code>".</dd>
<dt>{{domxref("PerformanceEntry.name")}}</dt>
<dd>返回 <code>"first-paint"</code> 或<code>"first-contentful-paint"</code>.</dd>
<dt>{{domxref("PerformanceEntry.startTime")}}</dt>
<dd>当开始“绘制“时返回 {{domxref("DOMHighResTimeStamp","timestamp")}}.</dd>
<dt>{{domxref("PerformanceEntry.duration")}}</dt>
<dd>返回 0.</dd>
</dl>
<h2 id="方法">方法</h2>
<p>这个接口没有方法</p>
<h2 id="例子">例子</h2>
<pre class="brush: js">function showPaintTimings() {
if (window.performance) {
let performance = window.performance;
let performanceEntries = performance.getEntriesByType('paint');
performanceEntries.forEach( (performanceEntry, i, entries) => {
console.log("The time to " + performanceEntry.name + " was " + performanceEntry.startTime + " milliseconds.");
});
} else {
console.log('Performance timing isn\'t supported.');
}
}</pre>
<p>上面例子输出如下</p>
<pre>The time to first-paint was 2785.915 milliseconds.
The time to first-contentful-paint was 2787.460 milliseconds.</pre>
<h2 id="规范">规范</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('Paint Timing','#sec-PerformancePaintTiming','PerformancePaintTiming')}}</td>
<td>{{Spec2('Paint Timing')}}</td>
<td>Initial definition.</td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
{{Compat("api.PerformancePaintTiming")}}
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