---
title: ServiceWorkerRegistration.update()
slug: Web/API/ServiceWorkerRegistration/update
tags:
  - 方法
  - 更新
translation_of: Web/API/ServiceWorkerRegistration/update
---
<div>{{APIRef("Service Workers API")}}</div>

<div>{{domxref("ServiceWorkerRegistration")}} 的<code><strong>update</strong></code>方法尝试更新service worker。获得worker脚本的URL，逐字节匹配新获取的worker和当前的worker，存在差异的时候安装新的worker。获取worker脚本的更新操作会忽略浏览器缓存的24小时前的内容。</div>

<div class="note">
<p><strong>注意</strong>: 这个特性也应用于 <a href="/en-US/docs/Web/API/Web_Workers_API">Web Workers</a>.</p>
</div>

<h2 id="Syntax" name="Syntax" style="line-height: 30px; font-size: 2.14285714285714rem;">语法</h2>

<pre>ServiceWorkerRegistration.update();</pre>

<h3 id="参数">参数</h3>

<p>None.</p>

<h3 id="返回">返回</h3>

<p>返回 {{domxref("Promise")}} 在resolve时对应一个 {{domxref("ServiceWorkerRegistration")}} 对象。</p>

<h2 id="示例">示例</h2>

<p>下面的示例注册一个service worker，然后绑定事件到按钮，这样你可以有需要时，明确的更新server worker：</p>

<pre class="brush: js">if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw-test/sw.js', {scope: 'sw-test'}).then(function(registration) {
    // registration worked
    console.log('Registration succeeded.');
    button.onclick = function() {
      registration.update();
    }
  }).catch(function(error) {
    // registration failed
    console.log('Registration failed with ' + error);
  });
};</pre>

<h2 id="标准">标准</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('Service Workers', '#service-worker-registration-update-method', 'ServiceWorkerRegistration.update()')}}</td>
   <td>{{Spec2('Service Workers')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>



<p>{{Compat("api.ServiceWorkerRegistration.update")}}</p>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Web/API/ServiceWorker_API/Using_Service_Workers">Using Service Workers</a></li>
 <li><a href="https://github.com/mdn/sw-test">Service workers basic code example</a></li>
 <li><a href="https://jakearchibald.github.io/isserviceworkerready/">Is ServiceWorker ready?</a></li>
 <li>{{jsxref("Promise")}}</li>
 <li><a href="/en-US/docs/Web/Guide/Performance/Using_web_workers">Using web workers</a></li>
</ul>