---
title: Path2D.addPath()
slug: Web/API/Path2D/addPath
translation_of: Web/API/Path2D/addPath
---
<div>{{APIRef("Canvas API")}}</div>

<p><code style="font-style: normal;"><strong>Path2D</strong></code><strong><code>.addPath()</code></strong> 是 Canvas 2D API 根据指定路径变量添加路径的方法。</p>

<h2 id="语法">语法</h2>

<pre class="syntaxbox">void <var><em>path</em>.addPath(path [, transform]);</var>
</pre>

<h3 id="参数">参数</h3>

<dl>
 <dt><code>path</code></dt>
 <dd>需要添加的 {{domxref("Path2D")}} 路径。</dd>
 <dt><code>transform</code> {{optional_inline}}</dt>
 <dd>{{domxref("SVGMatrix")}} 作为新增路径的变换矩阵。</dd>
</dl>

<h2 id="示例">示例</h2>

<h3 id="使用_addPath_方法">使用 <code>addPath</code> 方法</h3>

<p>这是一段使用 <code>addPath</code> 方法的简单的代码片段。</p>

<pre class="brush: js; highlight:[19]">var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

// Create a new path with a rect
var p1 = new Path2D();
p1.rect(0,0,100,100);

// Create another path with a rect
var p2 = new Path2D();
p2.rect(0,0,100,100);

// Create transformation matrix that moves vertically 300 points to the right
var m = document.createElementNS("http://www.w3.org/2000/svg", "svg").createSVGMatrix();
m.a = 1; m.b = 0;
m.c = 0; m.d = 1;
m.e = 300; m.f = 0;

// add the second path to the first path
p1.addPath(p2, m);

// Finally, fill the first path onto the canvas
ctx.fill(p1);
</pre>

<p>修改下面的代码并在线查看 canvas 的变化 (查看浏览器兼容性列表，确定你目前的浏览器是否支持这个方法)：</p>

<div class="hidden">
<h6 id="Playable_code">Playable code</h6>

<pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
&lt;div class="playable-buttons"&gt;
  &lt;input id="edit" type="button" value="Edit" /&gt;
  &lt;input id="reset" type="button" value="Reset" /&gt;
&lt;/div&gt;
&lt;textarea id="code" class="playable-code" style="height:220px;"&gt;
var p1 = new Path2D();
p1.rect(0,0,100,100);

var p2 = new Path2D();
p2.rect(0,0,100,100);

var m = document.createElementNS("http://www.w3.org/2000/svg", "svg").createSVGMatrix();
m.a = 1; m.b = 0;
m.c = 0; m.d = 1;
m.e = 300; m.f = 0;

p1.addPath(p2, m);
ctx.fill(p1);&lt;/textarea&gt;
</pre>

<pre class="brush: js">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('Playable_code', 700, 500) }}</p>

<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-path2d-addpath", "Path2D.addPath()")}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td>Initial defintion.</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>{{CompatNo}}</td>
   <td>{{CompatGeckoDesktop(34)}}</td>
   <td>{{CompatNo}}</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>{{CompatGeckoMobile(34)}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatNo}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="参见">参见</h2>

<ul>
 <li>接口定义， {{domxref("Path2D")}}.</li>
</ul>