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+---
+title: CanvasRenderingContext2D.save()
+slug: Web/API/CanvasRenderingContext2D/save
+translation_of: Web/API/CanvasRenderingContext2D/save
+---
+<div>{{APIRef}}</div>
+
+<p><code><strong>CanvasRenderingContext2D</strong></code><strong><code>.save()</code></strong> 是 Canvas 2D API 通过将当前状态放入栈中,保存 canvas 全部状态的方法。</p>
+
+<h2 id="语法">语法</h2>
+
+<pre class="syntaxbox">void <var><em>ctx</em>.save();</var></pre>
+
+<h2 id="绘制状态">绘制状态</h2>
+
+<p>保存到栈中的绘制状态有下面部分组成:</p>
+
+<ul>
+ <li>当前的变换矩阵。</li>
+ <li>当前的剪切区域。</li>
+ <li>当前的虚线列表.</li>
+ <li>以下属性当前的值: {{domxref("CanvasRenderingContext2D.strokeStyle", "strokeStyle")}}, {{domxref("CanvasRenderingContext2D.fillStyle", "fillStyle")}}, {{domxref("CanvasRenderingContext2D.globalAlpha", "globalAlpha")}}, {{domxref("CanvasRenderingContext2D.lineWidth", "lineWidth")}}, {{domxref("CanvasRenderingContext2D.lineCap", "lineCap")}}, {{domxref("CanvasRenderingContext2D.lineJoin", "lineJoin")}}, {{domxref("CanvasRenderingContext2D.miterLimit", "miterLimit")}}, {{domxref("CanvasRenderingContext2D.lineDashOffset", "lineDashOffset")}}, {{domxref("CanvasRenderingContext2D.shadowOffsetX", "shadowOffsetX")}}, {{domxref("CanvasRenderingContext2D.shadowOffsetY", "shadowOffsetY")}}, {{domxref("CanvasRenderingContext2D.shadowBlur", "shadowBlur")}}, {{domxref("CanvasRenderingContext2D.shadowColor", "shadowColor")}}, {{domxref("CanvasRenderingContext2D.globalCompositeOperation", "globalCompositeOperation")}}, {{domxref("CanvasRenderingContext2D.font", "font")}}, {{domxref("CanvasRenderingContext2D.textAlign", "textAlign")}}, {{domxref("CanvasRenderingContext2D.textBaseline", "textBaseline")}}, {{domxref("CanvasRenderingContext2D.direction", "direction")}}, {{domxref("CanvasRenderingContext2D.imageSmoothingEnabled", "imageSmoothingEnabled")}}.</li>
+</ul>
+
+<h2 id="示例">示例</h2>
+
+<h3 id="使用_save_方法">使用 <code>save</code> 方法</h3>
+
+<p>这是一段简单的代码片段,使用 <code>save</code> 方法保存默认的状态,这样,稍后你就可以使用默认的设置绘制一个矩形。</p>
+
+<h4 id="HTML">HTML</h4>
+
+<pre class="brush: html">&lt;canvas id="canvas"&gt;&lt;/canvas&gt;
+</pre>
+
+<h4 id="JavaScript">JavaScript</h4>
+
+<pre class="brush: js; highlight:[4]">var canvas = document.getElementById("canvas");
+var ctx = canvas.getContext("2d");
+
+ctx.save(); // 保存默认的状态
+
+ctx.fillStyle = "green";
+ctx.fillRect(10, 10, 100, 100);
+
+ctx.restore(); // 还原到上次保存的默认状态
+ctx.fillRect(150, 75, 100, 100);
+</pre>
+
+<p>修改下面的代码并在线查看 canvas 的变化:</p>
+
+<div style="display: none;">
+<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"&gt;
+ctx.save();
+ctx.fillStyle = "green";
+ctx.fillRect(10, 10, 100, 100);
+ctx.restore();
+ctx.fillRect(150, 75, 100, 100);&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, 360) }}</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-context-2d-save", "CanvasRenderingContext2D.save")}}</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.restore()")}}</li>
+</ul>