---
title: storage
slug: Mozilla/Add-ons/WebExtensions/API/storage
tags:
  - API
  - 擴充套件
translation_of: Mozilla/Add-ons/WebExtensions/API/storage
---
<div>
<div>{{AddonSidebar}}</div>

<p>讓套件可以存讀資料以及監聽儲存項目的更動。</p>

<p>儲存系統基於 <a href="https://developer.mozilla.org/en-US/docs/Web/API/Web_Storage_API">Web Storage API</a>，有一些不同，包括：</p>

<ul>
 <li>非同步</li>
 <li>值的作用域在套件而不是某個特定的網域（後端的所有腳本與內容腳本都可用同樣的鍵值）。</li>
 <li>儲存的值可以是任何的 JSON-ifiable 值而並非只能是 <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String">String</a></code>。這包括了： <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array">陣列</a></code>、<code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object">物件</a></code>。但只有在內容可以被以JSON表示的時候，這表示不包含DOM節點。你不需要特地把值轉爲JSON <code>Strings</code>來儲存它們，它們在內部就是以JSON來表示的。</li>
 <li>同一個API呼叫中可以設置或取得複數鍵值。</li>
</ul>

<p>要使用這個 API 你必須在 <a href="https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json">manifest.json</a> 裡面加入 "storage" 的<a href="https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/permissions">權限</a>。</p>

<p>每個套件都有自己的儲存空間，它們可以被切分爲不同種類的儲存。</p>

<p>雖然這個 API 與{{domxref("Window.localStorage")}}很相似，建議你不要在套件裡使用 <code>Window.localStorage</code> 儲存套件相關資料。Firefox 在用戶由於隱私問題清除歷史記錄與資料時會清除 localStorage API 儲存的資料，而 <code><a href="https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/storage/local">storage.local</a></code> API 儲存的則會留著。</p>

<div class="note">儲存空間不會被加密，所以你不應該把它們用來儲存用戶的機密資料。</div>

<h2 id="型別">型別</h2>

<dl>
 <dt>{{WebExtAPIRef("storage.StorageArea")}}</dt>
 <dd>表示儲存空間的物件。</dd>
 <dt>{{WebExtAPIRef("storage.StorageChange")}}</dt>
 <dd>表示儲存空間變化的物件。</dd>
</dl>

<h2 id="屬性">屬性</h2>

<p><code>storage</code> 有三個屬性，各自表示不同種類的儲存空間。</p>

<dl>
 <dt>{{WebExtAPIRef("storage.sync")}}</dt>
 <dd>表示 <code>sync</code> 儲存空間。<code>sync</code> 儲存空間裡的項目會被瀏覽器同步，所以可以跨裝置在所有已登入瀏覽器實例裡面使用。</dd>
 <dt>{{WebExtAPIRef("storage.local")}}</dt>
 <dd>表示 <code>local</code> 儲存空間。<code>local</code> 儲存空間裡的項目會被侷限在安裝套件的機器上。</dd>
 <dt>{{WebExtAPIRef("storage.managed")}}</dt>
 <dd>表示 <code>managed</code> 儲存空間。<code>managed</code> 儲存空間的項目由網域管理者設置而且對套件唯讀，修改這項會導致錯誤。</dd>
</dl>

<h2 id="事件">事件</h2>

<dl>
 <dt>{{WebExtAPIRef("storage.onChanged")}}</dt>
 <dd>當儲存空間裡的一個或更多項目被修改時觸發。</dd>
</dl>

<h2 id="瀏覽器兼容性">瀏覽器兼容性</h2>
</div>

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

<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/storage"><code>chrome.storage</code></a> API. This documentation is derived from <a href="https://chromium.googlesource.com/chromium/src/+/master/extensions/common/api/storage.json"><code>storage.json</code></a> in the Chromium code.</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>

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