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---
title: ServiceWorker
slug: Web/API/ServiceWorker
tags:
- API
- Draft
- Experimental
- Service Worker
- 离线
translation_of: Web/API/ServiceWorker
---
<div>{{SeeCompatTable}} {{APIRef("Service Workers API")}}</div>
<div>ServiceWorker API 的<a href="https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorker_API"> ServiceWorker接口</a> 提供一个对一个服务工作者的引用。 多个浏览上下文（例如页面，工作者等）可以与相同的服务工作者相关联，每个都通过唯一的ServiceWorker对象。</div>
<div> </div>
<p>一个ServiceWorker对象在 {{domxref("ServiceWorkerRegistration.active")}} 属性和 {{domxref("ServiceWorkerContainer.controller")}} 属性中可用 — 这是一个激活并在控制页面的service worker(service worker成功注册,被控页面已经重新加载完毕.)</p>
<p>ServiceWorker接口被分配了一系列生命周期事件 --- 安装和激活 --- 以及功能型的事件,包括 fetch.一个ServiceWorker对象有一个与之关联的 {{domxref("ServiceWorker.state")}},指示着它的生命周期.</p>
<h2 id="属性">属性</h2>
<p><em>ServiceWorker 接口继承它父类{{domxref("Worker")}}的属性.</em></p>
<dl>
<dt>{{domxref("ServiceWorker.scriptURL")}} {{readonlyinline}}</dt>
<dd>返回作为 {{domxref("ServiceWorkerRegistration")}} 一部分所定义的ServiceWorker序列化脚本URL.这个URL必须和注册该ServiceWorker的文档处于同一域.</dd>
<dt>{{domxref("ServiceWorker.state")}} {{readonlyinline}}</dt>
<dd>返回service worker的状态.其值可能是如下之一:installing,installed,activating,activated或者是redundant.</dd>
</dl>
<h3 id="Event_handlers">Event handlers</h3>
<dl>
<dt>{{domxref("ServiceWorker.onstatechange")}} {{readonlyinline}}</dt>
<dd>一个一旦 {{domxref("ServiceWorker.state")}} 发生改变时,即一个类型为statechange事件触发时就会被调用的 {{domxref("EventListener")}} 属性.</dd>
</dl>
<h2 id="方法">方法</h2>
<dl>
<dd><em>ServiceWorker 接口继承它父类 {{domxref("Worker")}} 的方法 ,并带有一个 {{domxref("Worker.terminate")}} 的异常 --- 它不应该从service workers.ServiceWorker中访问.</em></dd>
</dl>
<h2 id="例子">例子</h2>
<p>代码段来自<a href="https://github.com/GoogleChrome/samples/blob/gh-pages/service-worker/registration-events/index.html">service worker registration-events sample</a> (<a href="https://googlechrome.github.io/samples/service-worker/registration-events/">live demo</a>). 这段代码监听了{{domxref("ServiceWorker.state")}} 的变化并且返回它的值.</p>
<pre class="brush: js">if ('serviceWorker' in navigator) {
navigator.serviceWorker.register('service-worker.js', {
scope: './'
}).then(function (registration) {
var serviceWorker;
if (registration.installing) {
serviceWorker = registration.installing;
document.querySelector('#kind').textContent = 'installing';
} else if (registration.waiting) {
serviceWorker = registration.waiting;
document.querySelector('#kind').textContent = 'waiting';
} else if (registration.active) {
serviceWorker = registration.active;
document.querySelector('#kind').textContent = 'active';
}
if (serviceWorker) {
// logState(serviceWorker.state);
serviceWorker.addEventListener('statechange', function (e) {
// logState(e.target.state);
});
}
}).catch (function (error) {
// Something went wrong during registration. The service-worker.js file
// might be unavailable or contain a syntax error.
});
} else {
// The current browser doesn't support service workers.
}</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('Service Workers', '#service-worker-obj', 'ServiceWorker')}}</td>
<td>{{Spec2('Service Workers')}}</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.ServiceWorker")}}
<h2 id="参见">参见</h2>
<ul>
<li><a href="https://serviceworke.rs">ServiceWorker Cookbook</a></li>
<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", "Promises")}}</li>
<li><a href="/en-US/docs/Web/Guide/Performance/Using_web_workers">Using web workers</a></li>
</ul>
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