---
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>