---
title: alarms
slug: Mozilla/Add-ons/WebExtensions/API/alarms
translation_of: Mozilla/Add-ons/WebExtensions/API/alarms
---
<div>{{AddonSidebar}}</div>

<p>在未来一个特定的时间运行的计划任务代码。这很像<code><a href="/zh-CN/docs/Web/API/WindowTimers/setTimeout">setTimeout()</a></code>和<code><a href="/zh-CN/docs/Web/API/WindowTimers/setInterval">setInterval()</a></code>，不过这些函数仅可以按需使用而不能在后台页面工作。</p>

<p>想要使用这个API，您需要获取"alarms"的<a href="/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/permissions">permission</a>。</p>

<h2 id="类型">类型</h2>

<dl>
 <dt>{{WebExtAPIRef("alarms.Alarm")}}</dt>
 <dd>Information about a particular alarm.</dd>
</dl>

<h2 id="方法">方法</h2>

<dl>
 <dt>{{WebExtAPIRef("alarms.create()")}}</dt>
 <dd>创建新的alarm.</dd>
 <dt>{{WebExtAPIRef("alarms.get()")}}</dt>
 <dd>通过名称获取指定的alarm.</dd>
 <dt>{{WebExtAPIRef("alarms.getAll()")}}</dt>
 <dd>获取所有的alarm.</dd>
 <dt>{{WebExtAPIRef("alarms.clear()")}}</dt>
 <dd>清除指定名称的alarm.</dd>
 <dt>{{WebExtAPIRef("alarms.clearAll()")}}</dt>
 <dd>清除所有的alarm.</dd>
</dl>

<h2 id="事件">事件</h2>

<dl>
 <dt>{{WebExtAPIRef("alarms.onAlarm")}}</dt>
 <dd>当alarm发生的时候触发.</dd>
</dl>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<p>{{Compat("webextensions.api.alarms")}}</p>

<div class="hidden note">
<p>The "Chrome incompatibilities" section is included from <a href="https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Chrome_incompatibilities"> https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Chrome_incompatibilities</a> using the <a href="/en-US/docs/Template:WebExtChromeCompat">WebExtChromeCompat</a> macro.</p>

<p>If you need to update this content, edit <a href="https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Chrome_incompatibilities">https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Chrome_incompatibilities</a>, then shift-refresh this page to see your changes.</p>
</div>

<p> {{WebExtExamples("h2")}}</p>

<div class="note"><strong>Acknowledgements</strong>

<p>This API is based on Chromium's <a href="https://developer.chrome.com/extensions/alarms"><code>chrome.alarms</code></a> API.</p>

<p>Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.</p>
</div>