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---
title: CanvasRenderingContext2D.fillRect()
slug: Web/API/CanvasRenderingContext2D/fillRect
translation_of: Web/API/CanvasRenderingContext2D/fillRect
---
<div>{{APIRef}}</div>
<p><code><strong>CanvasRenderingContext2D</strong></code><strong><code>.fillRect()</code></strong> 是Canvas 2D API 绘制填充矩形的方法。当前渲染上下文中的<code>fillStyle</code> 属性决定了对这个矩形对的填充样式。<br>
<br>
这个方法是直接在画布上绘制填充，并不修改当前路径，所以在这个方法后面调用 {{domxref("CanvasRenderingContext2D.fill()", "fill()")}} 或者{{domxref("CanvasRenderingContext2D.stroke()", "stroke()")}}方法并不会对这个方法有什么影响。</p>
<h2 id="语法">语法</h2>
<pre class="syntaxbox notranslate">void <var><em>ctx</em>.fillRect(x, y, width, height);</var>
</pre>
<p><code>fillRect()</code>方法绘制一个填充了内容的矩形，这个矩形的开始点（左上点）在<code>(x, y)</code> ，它的宽度和高度分别由<code>width</code> 和 <code>height</code> 确定，填充样式由当前的<code>fillStyle</code> 决定。</p>
<h3 id="参数">参数</h3>
<dl>
<dt><code>x</code></dt>
<dd>矩形起始点的 x 轴坐标。</dd>
<dt><code>y</code></dt>
<dd>矩形起始点的 y 轴坐标。</dd>
<dt><code>width</code></dt>
<dd>矩形的宽度。</dd>
<dt><code>height</code></dt>
<dd>矩形的高度。</dd>
</dl>
<h2 id="示例">示例</h2>
<h3 id="一个填充矩形的例子">一个填充矩形的例子</h3>
<p>这个例子使用<code>fillRect()</code>方法绘制了一个用绿色填充的矩形。</p>
<h4 id="HTML">HTML</h4>
<pre class="brush: html notranslate"><canvas id="canvas"></canvas>
</pre>
<h4 id="JavaScript">JavaScript</h4>
<p>下面绘制的矩形左上顶点在(20, 10)，宽高分别是150和100像素。</p>
<pre class="notranslate">const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.fillStyle = 'green';
ctx.fillRect(20, 10, 150, 100);</pre>
<h4 id="结果">结果</h4>
<div style="display: none;">
<h6 id="Playable_code">Playable code</h6>
<pre class="brush: html notranslate"><canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
<input id="edit" type="button" value="Edit" />
<input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code">
ctx.fillStyle = "green";
ctx.fillRect(10, 10, 100, 100);</textarea>
</pre>
<pre class="brush: js notranslate">var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;
function drawCanvas() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
eval(textarea.value);
}
reset.addEventListener("click", function() {
textarea.value = code;
drawCanvas();
});
edit.addEventListener("click", function() {
textarea.focus();
})
textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);
</pre>
</div>
<p>{{ EmbedLiveSample('A_simple_filled_rectangle', 700, 180) }}</p>
<h3 id="填充整个画布">填充整个画布</h3>
<p>下面这个代码片段使用本方法填充了整个画布。这样做通常的目的是在开始绘制其他内容前设置一个背景。为了达到这样的效果，需要让填充的范围和画布的范围相同，需要访问{{HtmlElement("canvas")}}元素的<code>width</code> 和 <code>height</code> 属性。</p>
<pre class="notranslate">const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.fillRect(0, 0, canvas.width, canvas.height);</pre>
<h2 id="规范描述">规范描述</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">备注</th>
</tr>
<tr>
<td>{{SpecName('HTML WHATWG', "scripting.html#dom-context-2d-fillrect", "CanvasRenderingContext2D.fillRect")}}</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>{{CompatibilityTable}}</p>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Chrome for Android</th>
<th>Firefox Mobile (Gecko)</th>
<th>IE Mobile</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
</tr>
<tr>
<td>Basic support</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatVersionUnknown}}</td>
</tr>
</tbody>
</table>
</div>
<h2 id="参见">参见</h2>
<ul>
<li>接口定义，{{domxref("CanvasRenderingContext2D")}}</li>
<li>{{domxref("CanvasRenderingContext2D.fillStyle")}}</li>
<li>{{domxref("CanvasRenderingContext2D.clearRect()")}}</li>
<li>{{domxref("CanvasRenderingContext2D.strokeRect()")}}</li>
</ul>
|
