---
title: FileReader.readyState
slug: Web/API/FileReader/readyState
translation_of: Web/API/FileReader/readyState
---
<div>{{APIRef("File API")}}</div>

<p>提供目前讀取狀態</p>

<h2 id="語法">語法</h2>

<pre class="syntaxbox">var state = <em>instanceOfFileReader</em>.readyState
</pre>

<h2 id="數值">數值</h2>

<p>數字代表 {{domxref("FileReader")}} API 三個可能的狀態：</p>

<p>{{page("/en-US/docs/Web/API/FileReader","State constants")}}</p>

<h2 id="規格">規格</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">規格</th>
   <th scope="col">狀態</th>
   <th scope="col">說明</th>
  </tr>
  <tr>
   <td>{{SpecName("File API", "#FileReader-interface", "FileReader")}}</td>
   <td>{{Spec2("File API")}}</td>
   <td>初始化定義</td>
  </tr>
 </tbody>
</table>

<h2 id="瀏覽器相容性">瀏覽器相容性</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>功能</th>
   <th>Firefox (Gecko)</th>
   <th>Chrome</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>基本支援</td>
   <td>{{CompatGeckoDesktop("1.9.2")}}<sup>[1]</sup></td>
   <td>7</td>
   <td>10<sup>[2]</sup></td>
   <td>12.02<sup>[3]</sup></td>
   <td>6.0.2</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>功能</th>
   <th>Firefox 手機版 (Gecko)</th>
   <th>Android</th>
   <th>IE 手機版</th>
   <th>Opera 手機版</th>
   <th>Safari 手機版</th>
  </tr>
  <tr>
   <td>基本支援</td>
   <td>32</td>
   <td>3</td>
   <td>10</td>
   <td>11.5</td>
   <td>6.1</td>
  </tr>
 </tbody>
</table>
</div>

<p>[1] Prior to Gecko 2.0 beta 7 (Firefox 4.0 beta 7), all {{domxref("Blob")}} parameters below were {{domxref("File")}} parameters; this has since been updated to match the specification correctly. Prior to Gecko 13.0 {{geckoRelease("13.0")}} the <code>FileReader.error</code> property returned a {{domxref("FileError")}} object. This interface has been removed and <code>FileReader.error</code> is now returning the {{domxref("DOMError")}} object as defined in the latest FileAPI draft.</p>

<p>[2] IE9 has a <a href="http://html5labs.interoperabilitybridges.com/prototypes/fileapi/fileapi/info">File API Lab</a>.</p>

<p>[3] Opera has <a href="http://www.opera.com/docs/specs/presto28/file/">partial support</a> in 11.1.</p>

<h2 id="閱讀更多">閱讀更多</h2>

<ul>
 <li>{{domxref("Blob")}}</li>
</ul>