---
title: CSSStyleDeclaration.setProperty()
slug: Web/API/CSSStyleDeclaration/setProperty
translation_of: Web/API/CSSStyleDeclaration/setProperty
---
<p>{{ APIRef("CSSOM") }}</p>

<p><span class="seoSummary"><strong><code>CSSStyleDeclaration.setProperty()</code></strong> 方法接口为一个声明了CSS样式的对象设置一个新的值 。</span></p>

<h2 id="语法">语法</h2>

<pre><em>style</em>.setProperty(<em>propertyName</em>, <em>value, priority</em>);</pre>

<h3 id="参数">参数</h3>

<ul>
 <li><em><code>propertyName</code></em> 是一个 {{domxref('DOMString')}} ，代表被更改的CSS属性。</li>
 <li><em><code>value</code></em>{{optional_inline}} 是一个 {{domxref('DOMString')}} ，含有新的属性值。如果没有指定, 则当作空字符串。
  <ul>
   <li>注意: <em><code>value</code></em> 不能包含 <code>"!important"</code> --那个应该使用 <em><code>priority</code></em> 参数.</li>
  </ul>
 </li>
 <li><em><code>priority</code></em>{{optional_inline}} 是一个 {{domxref('DOMString')}} 允许设置 "important" CSS 优先级。如果没有指定, 则当作空字符串。</li>
</ul>

<h3 id="返回值">返回值</h3>

<ul>
 <li>{{jsxref('undefined')}}</li>
</ul>

<h3 id="异常">异常</h3>

<ul>
 <li>{{domxref('DOMException')}} (NoModificationAllowedError)： 如果属性或装饰块为只读的，抛出此异常。</li>
</ul>

<p>JavaScript 有一个特别的，更简单的在 CSSStyleDeclaration 对象上设置CSS属性值的语法：</p>

<pre class="syntaxbox"><em>style</em>.cssPropertyName = 'value';</pre>

<h2 id="示例">示例</h2>

<p>下面的Javascript代码为一个选中元素样式的 <code>margin</code> 属性设置一个新的值:</p>

<pre class="brush: js">var declaration = document.styleSheets[0].rules[0].style;
declaration.setProperty('margin', '1px 2px');
// Equivalent to:
// declaration.margin = '1px 2px';
</pre>

<h2 id="说明">  说明</h2>

<table>
 <thead>
  <tr>
   <th scope="col">描述</th>
   <th scope="col">状态</th>
   <th scope="col">注释</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName('CSSOM', '#dom-cssstyledeclaration-setproperty', 'CSSStyleDeclaration.setProperty()')}}</td>
   <td>工作草案</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('DOM2 Style', 'css.html#CSS-CSSStyleDeclaration', 'CSSStyleDeclaration')}}</td>
   <td>被废弃</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容">浏览器兼容</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <thead>
  <tr>
   <th scope="col">特性</th>
   <th scope="col">Chrome</th>
   <th scope="col">Edge</th>
   <th scope="col">Firefox (Gecko)</th>
   <th scope="col">Internet Explorer</th>
   <th scope="col">Opera</th>
   <th scope="col">Safari (WebKit)</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>基础支持</td>
   <td>{{CompatVersionUnknown}}</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>特性</th>
   <th>Android</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
   <th>Chrome for Android</th>
  </tr>
  <tr>
   <td>基础支持</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>

<div>
<h3 id="want_learn_more">want learn more</h3>
<a href="https://developer.mozilla.org/zh-CN/docs/Web/API/Window/getComputedStyle">getComputedStyle</a><br>
<a href="https://developer.mozilla.org/zh-CN/docs/Web/API/CSSStyleDeclaration/getPropertyValue">getPropertyValue</a></div>
</div>