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---
title: progress event
slug: Web/Events/进度条
tags:
- API
- Event
- Reference
- Web
- XMLHttpRequest
- progress
translation_of: Web/API/XMLHttpRequest/progress_event
---
<p>{{APIRef}}</p>
<p><strong><code>progress</code></strong>事件会在请求接收到数据的时候被周期性触发。</p>
<table class="properties">
<tbody>
<tr>
<th scope="row">Bubbles</th>
<td>No</td>
</tr>
<tr>
<th scope="row">Cancelable</th>
<td>No</td>
</tr>
<tr>
<th scope="row">Interface</th>
<td>{{domxref("ProgressEvent")}}</td>
</tr>
<tr>
<th scope="row">Event handler property</th>
<td>{{domxref("XMLHttpRequestEventTarget/onprogress", "onprogress")}}</td>
</tr>
</tbody>
</table>
<h2 id="示例">示例</h2>
<h3 id="Live_example">Live example</h3>
<h4 id="HTML">HTML</h4>
<pre class="brush: html"><div class="controls">
<input class="xhr success" type="button" name="xhr" value="Click to start XHR (success)" />
<input class="xhr error" type="button" name="xhr" value="Click to start XHR (error)" />
<input class="xhr abort" type="button" name="xhr" value="Click to start XHR (abort)" />
</div>
<textarea readonly class="event-log"></textarea></pre>
<div class="hidden">
<h4 id="CSS">CSS</h4>
<pre class="brush: css">.event-log {
width: 25rem;
height: 4rem;
border: 1px solid black;
margin: .5rem;
padding: .2rem;
}
input {
width: 11rem;
margin: .5rem;
}
</pre>
</div>
<h4 id="JS">JS</h4>
<pre class="brush: js">const xhrButtonSuccess = document.querySelector('.xhr.success');
const xhrButtonError = document.querySelector('.xhr.error');
const xhrButtonAbort = document.querySelector('.xhr.abort');
const log = document.querySelector('.event-log');
function handleEvent(e) {
log.textContent = log.textContent + `${e.type}: ${e.loaded} bytes transferred\n`;
}
function addListeners(xhr) {
xhr.addEventListener('loadstart', handleEvent);
xhr.addEventListener('load', handleEvent);
xhr.addEventListener('loadend', handleEvent);
xhr.addEventListener('progress', handleEvent);
xhr.addEventListener('error', handleEvent);
xhr.addEventListener('abort', handleEvent);
}
function runXHR(url) {
log.textContent = '';
const xhr = new XMLHttpRequest();
addListeners(xhr);
xhr.open("GET", url);
xhr.send();
return xhr;
}
xhrButtonSuccess.addEventListener('click', () => {
runXHR('https://mdn.mozillademos.org/files/16553/DgsZYJNXcAIPwzy.jpg');
});
xhrButtonError.addEventListener('click', () => {
runXHR('https://somewhere.org/i-dont-exist');
});
xhrButtonAbort.addEventListener('click', () => {
runXHR('https://mdn.mozillademos.org/files/16553/DgsZYJNXcAIPwzy.jpg').abort();
});</pre>
<h4 id="Result">Result</h4>
<p>{{ EmbedLiveSample('Live_example', '100%', '150px') }}</p>
<h2 id="规范">规范</h2>
<table class="standard-table">
<thead>
<tr>
<th scope="col">Specification</th>
<th scope="col">Status</th>
<th scope="col">Comment</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{SpecName('XMLHttpRequest', '#event-xhr-progress')}}</td>
<td>{{Spec2('XMLHttpRequest')}}</td>
<td></td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<p>{{Compat("api.XMLHttpRequest.progress_event")}}</p>
<h2 id="相关链接">相关链接</h2>
<ul>
<li>Related events: {{domxref("XMLHttpRequest/loadstart_event", "loadstart")}}, {{domxref("XMLHttpRequest/load_event", "load")}}, {{domxref("XMLHttpRequest/loadend_event", "loadend")}}, {{domxref("XMLHttpRequest/error_event", "error")}}, {{domxref("XMLHttpRequest/abort_event", "abort")}}</li>
<li><a href="/en-US/docs/DOM/XMLHttpRequest/Using_XMLHttpRequest#Monitoring_progress">Monitoring progress</a></li>
</ul>
|
