files/zh-cn/web/api/canvasrenderingcontext2d/canvas/index.html


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---
title: CanvasRenderingContext2D.canvas
slug: Web/API/CanvasRenderingContext2D/canvas
tags:
  - API
  - Canvas
translation_of: Web/API/CanvasRenderingContext2D/canvas
---
<div>{{APIRef}}</div>

<p><code><strong>CanvasRenderingContext2D</strong></code><strong><code><span>.canvas</span></code></strong> 属性是 <a href="https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API">Canvas API</a> 的一部分，是对与给定上下文关联的{{domxref("HTMLCanvasElement")}}对象的只读引用。如果没有 {{HTMLElement("canvas")}} 元素与之对应，对象值为{{jsxref("null")}} 。</p>

<h2 id="Syntax" name="Syntax">语法</h2>

<pre class="syntaxbox"><var><em>ctx</em></var>.canvas;</pre>

<h2 id="示例">示例</h2>

<p>给出 {{HTMLElement("canvas")}} 元素：</p>

<pre class="brush: html">&lt;canvas id="canvas"&gt;&lt;/canvas&gt;
</pre>

<p>你可以通过CanvasRenderingContext2D调用内部的canvas属性，获取canvas的一个反向引用:</p>

<pre class="brush: js">var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.canvas // HTMLCanvasElement
</pre>

<h2 id="规范描述">规范描述</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('HTML WHATWG', "scripting.html#dom-context-2d-canvas", "CanvasRenderingContext2D.canvas")}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<p>{{Compat("api.CanvasRenderingContext2D.canvas")}}</p>

<h2 id="See_Also" name="See_Also">参见</h2>

<ul>
 <li>{{domxref("CanvasRenderingContext2D")}} 接口</li>
 <li><a href="https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API">Canvas API</a></li>
</ul>