files/zh-cn/web/api/webglrenderingcontext/iscontextlost/index.html


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---
title: WebGLRenderingContext.isContextLost()
slug: Web/API/WebGLRenderingContext/isContextLost
tags:
  - WebGL上下文丢失
translation_of: Web/API/WebGLRenderingContext/isContextLost
---
<div>{{APIRef("WebGL")}}</div>

<p><code><strong>WebGLRenderingContext.isContextLost()</strong></code> 方法返回一个{{jsxref("Boolean")}} 标记WebGL的上下文是否已经丢失。</p>

<h2 id="语法">语法</h2>

<pre class="syntaxbox"><var><em>gl</em></var>.isContextLost();</pre>

<h3 id="返回值">返回值</h3>

<p> {{jsxref("Boolean")}}。如果上下文丢失则返回true，否则返回false。</p>

<h2 id="样例">样例</h2>

<p>比如，当检查程序链接成功时，你也可以检查是否上下文已经丢失。</p>

<pre class="brush: js">gl.linkProgram(program);

if (!gl.getProgramParameter(program, gl.LINK_STATUS) &amp;&amp; !gl.isContextLost()) {
  var info = gl.getProgramInfoLog(program);
  console.log('Error linking program:\n' + info);
}</pre>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName("WebGL", "#5.14.13", "WebGLRenderingContext.isContextLost")}}</td>
   <td>{{Spec2("WebGL")}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<p class="hidden">The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</p>

<p>{{Compat("api.WebGLRenderingContext.isContextLost")}}</p>

<h2 id="另见">另见</h2>

<ul>
 <li>The {{domxref("WebGLContextEvent")}} signals changes in the context state.</li>
</ul>