---
title: BlobBuilder
slug: Web/API/BlobBuilder
translation_of: Web/API/BlobBuilder
---
<p>{{ deprecated_header() }}</p>
<p>{{ SeeCompatTable() }}</p>
<p>The <code>BlobBuilder</code> interface provides an easy way to construct {{ domxref("Blob") }} objects. Just create a <code>BlobBuilder</code> and append chunks of data to it by calling the {{ manch("append") }} method. When you're done building your blob, call {{ manch("getBlob") }} to retrieve a {{ domxref("Blob") }} containing the data you sent into the blob builder.</p>
<div class="note">
  <strong>注:</strong><code>BlobBuilder</code>接口已经废弃,请使用新版草案中引入的 {{domxref('Blob') }}构造函数.</div>
<h2 id="Method_overview" name="Method_overview">方法概述</h2>
<table class="standard-table">
  <tbody>
    <tr>
      <td><code>void <a href="/zh-CN/DOM/BlobBuilder#append()" title="zh-CN/DOM/BlobBuilder#append()">append</a>(in ArrayBuffer data);</code></td>
    </tr>
    <tr>
      <td><code>void <a href="/zh-CN/DOM/BlobBuilder#append()" title="zh-CN/DOM/BlobBuilder#append()">append</a>(in Blob data);</code></td>
    </tr>
    <tr>
      <td><code>void <a href="/zh-CN/DOM/BlobBuilder#append()" title="zh-CN/DOM/BlobBuilder#append()">append</a>(in String data, [optional] in String endings);</code></td>
    </tr>
    <tr>
      <td><code>Blob <a href="/zh-CN/DOM/BlobBuilder#getBlob()" title="zh-CN/DOM/BlobBuilder#getBlob()">getBlob</a>([optional] in DOMString contentType);</code></td>
    </tr>
    <tr>
      <td><code>File <a href="/zh-CN/DOM/BlobBuilder#getFile()" title="zh-CN/DOM/BlobBuilder#getFile()">getFile</a>(in DOMString name, [optional] in DOMString contentType);</code></td>
    </tr>
  </tbody>
</table>
<h2 id="方法">方法</h2>
<h3 id="append()">append()</h3>
<p>Appends the contents of the specified JavaScript object to the {{ domxref("Blob") }} being built. If the value you specify isn't a {{ domxref("Blob") }}, <a href="/zh-CN/JavaScript_typed_arrays/ArrayBuffer" title="zh-CN/JavaScript typed arrays/Arraybuffer"><code>ArrayBuffer</code></a>, or <a href="/zh-CN/JavaScript/Reference/Global_Objects/String" title="zh-CN/JavaScript/Reference/Global Objects/String"><code>String</code></a>, the value is coerced to a string before being appended to the blob.</p>
<pre>void append(
  in ArrayBuffer data
);

void append(
  in Blob data
);


void append(
  in String data,
  [optional] in String endings
);
</pre>
<h6 id="参数">参数</h6>
<dl>
  <dt>
    <code>data</code></dt>
  <dd>
    The data to append to the {{ domxref("Blob") }} being constructed.</dd>
  <dt>
    <code>endings</code></dt>
  <dd>
    Specifies how strings containing <code>\n</code> are to be written out. This can be <code>"transparent"</code> (endings unchanged) or <code>"native"</code> (endings changed to match host OS filesystem convention). The default value is <code>"transparent"</code>.</dd>
</dl>
<h3 id="getBlob()">getBlob()</h3>
<p>Returns the {{ domxref("Blob") }} object that has been constructed using the data passed through calls to {{ manch("append") }}.</p>
<pre class="eval">Blob getBlob(
  in DOMString contentType {{ optional_inline() }}
);
</pre>
<h6 id="参数_2">参数</h6>
<dl>
  <dt>
    contentType {{ optional_inline() }}</dt>
  <dd>
    The MIME type of the data to be returned in the {{ domxref("Blob") }}. This will be the value of the <code>Blob</code> object's type property.</dd>
</dl>
<h6 id="返回值">返回值</h6>
<p>A {{ domxref("Blob") }} object containing all of the data passed to any calls to {{ manch("append") }} made since the <code>BlobBuilder</code> was created. This also resets the <code>BlobBuilder</code> so that the next call to {{ manch("append") }} is starting a new, empty blob.</p>
<h3 id="getFile()_non-standard_inline()">getFile() {{ non-standard_inline() }}</h3>
<p>返回一个{{ domxref("File") }}对象.</p>
<pre class="eval">File getFile(
  in DOMString name,
  [optional] in DOMString contentType
);
</pre>
<h6 id="参数_3">参数</h6>
<dl>
  <dt>
    name</dt>
  <dd>
    文件名.</dd>
  <dt>
    contentType {{ optional_inline() }}</dt>
  <dd>
    设置返回的{{ domxref("File") }}对象中的数据的MIME类型.这个值将会成为返回<code>的File</code>对象的type属性的值.</dd>
</dl>
<h6 id="返回值_2">返回值</h6>
<p>一个{{ domxref("File") }}对象.</p>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
{{Compat("api.BlobBuilder")}}

<h2 id="相关链接">相关链接</h2>
<ul>
  <li>{{ spec("http://dev.w3.org/2009/dap/file-system/file-writer.html#idl-def-BlobBuilder", "File API Specification: BlobBuilder", "ED") }}</li>
  <li>{{ domxref("Blob") }}</li>
  <li>{{ domxref("File") }}</li>
</ul>