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---
title: Body.blob()
slug: Web/API/Body/blob
tags:
- Body.blob()
translation_of: Web/API/Body/blob
---
<p>{{APIRef("Fetch")}}</p>
<p>{{domxref("Body")}} mixin的 <strong><code>blob()</code></strong>方法使用一个 {{domxref("Response")}} 流，并将其读取完成。它返回一个使用{{domxref("Blob")}}解决的promise。</p>
<h2 id="句法">句法</h2>
<pre class="brush: js">response.blob().then(function(myBlob) {
// do something with myBlob
});</pre>
<h3 id="参数">参数</h3>
<p>None.</p>
<h3 id="返回值">返回值</h3>
<p>A promise that resolves with a {{domxref("Blob")}}.</p>
<h2 id="例子">例子</h2>
<p>在我们 <a href="https://github.com/mdn/fetch-examples/tree/gh-pages/fetch-request">fetch request example</a> (run <a href="http://mdn.github.io/fetch-examples/fetch-request/">fetch request live</a>)中，我们使用<a href="/zh-CN/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/RequestFilter">Request.Request</a>构造方法创建了一个新的request对象，然后使用它来获取一个JPG文件。当fetch成功的时候，我们使用blob()从response中读取一个<a href="/zh-CN/docs/Web/API/Blob">Blob</a>对象，并使用<a href="/zh-CN/docs/Web/API/URL/createObjectURL">URL.createObjectURL</a> 将它放入一个object URL ，然后把URL设置为<a href="/zh-CN/docs/Web/HTML/Element/img">img</a>元素的src属性以显示这张图片。</p>
<p> </p>
<pre class="brush: js">var myImage = document.querySelector('img');
var myRequest = new Request('flowers.jpg');
fetch(myRequest)
.then(function(response) {
return response.blob();
})
.then(function(myBlob) {
var objectURL = URL.createObjectURL(myBlob);
myImage.src = objectURL;
});
</pre>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">说明</th>
</tr>
<tr>
<td>{{SpecName('Fetch','#dom-body-blob','blob()')}}</td>
<td>{{Spec2('Fetch')}}</td>
<td> </td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<p>{{ CompatibilityTable}}</p>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Edge</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari (WebKit)</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{ CompatChrome(42) }} [1]<br>
</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{ CompatGeckoDesktop(39)}} [2]</td>
<td>{{ CompatNo }}</td>
<td>
<p>29 [3]</p>
</td>
<td>{{ CompatNo }}</td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Edge</th>
<th>Firefox Mobile (Gecko)</th>
<th>Firefox OS (Gecko)</th>
<th>IE Phone</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
<th>Chrome for Android</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{ CompatNo }}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{ CompatNo }}</td>
<td>{{ CompatNo }}</td>
<td>{{ CompatNo }}</td>
<td>{{ CompatNo }}</td>
<td>{{ CompatNo }}</td>
<td>{{ CompatNo }}</td>
</tr>
</tbody>
</table>
</div>
<p>[1] Behind a preference in version 41.</p>
<p>[2] Behind a preference starting with version 34.</p>
<p>[3] Behind a preference in version 28.</p>
<h2 id="另见">另见</h2>
<ul>
<li><a href="/en-US/docs/Web/API/ServiceWorker_API">ServiceWorker API</a></li>
<li><a href="/en-US/docs/Web/HTTP/Access_control_CORS">HTTP access control (CORS)</a></li>
<li><a href="/en-US/docs/Web/HTTP">HTTP</a></li>
</ul>
|
