--- title: 后代选择器 slug: Web/CSS/Descendant_combinator tags: - CSS - Selectors translation_of: Web/CSS/Descendant_combinator --- <div>{{CSSRef("Selectors")}}</div> <p><strong>后代组合器</strong>(通常用单个空格(<code> </code>)字符表示)组合了两个选择器,如果第二个选择器匹配的元素具有与第一个选择器匹配的祖先(父母,父母的父母,父母的父母的父母等)元素,则它们将被选择。利用后代组合器的选择器称为<dfn>后代选择器</dfn>。</p> <pre class="brush: css no-line-numbers notranslate">/* List items that are descendants of the "my-things" list */ ul.my-things li { margin: 2em; }</pre> <p>从技术上讲,后代组合器是两个选择器之间的一个或多个 {{Glossary("CSS")}} 空格字符-空格字符和/或四个控制字符之一:回车,换页,换行和制表符在没有其他组合器的情况下。此外,组成组合器的空白字符可以包含任意数量的CSS注释。</p> <h2 id="语法">语法</h2> <pre class="syntaxbox notranslate"><var>selector1</var> <var>selector2</var> { <var>/* property declarations */</var> }</pre> <h2 id="Examples">Examples</h2> <h3 id="CSS">CSS</h3> <pre class="brush: css notranslate">li { list-style-type: disc; } li li { list-style-type: circle; } </pre> <h3 id="HTML">HTML</h3> <pre class="brush: html notranslate"><ul> <li> <div>Item 1</div> <ul> <li>Subitem A</li> <li>Subitem B</li> </ul> </li> <li> <div>Item 2</div> <ul> <li>Subitem A</li> <li>Subitem B</li> </ul> </li> </ul> </pre> <h3 id="Result">Result</h3> <p>{{EmbedLiveSample("Examples", "100%", 160)}}</p> <h2 id="规范">规范</h2> <table class="standard-table"> <thead> <tr> <th scope="col">Specification</th> <th scope="col">Status</th> <th scope="col">Comment</th> </tr> </thead> <tbody> <tr> <td>{{SpecName("CSS4 Selectors", "#descendant-combinators", "descendant combinator")}}</td> <td>{{Spec2("CSS4 Selectors")}}</td> <td></td> </tr> <tr> <td>{{SpecName("CSS3 Selectors", "#descendant-combinators", "descendant combinator")}}</td> <td>{{Spec2("CSS3 Selectors")}}</td> <td></td> </tr> <tr> <td>{{SpecName("CSS2.1", "selector.html#descendant-selectors", "descendant selectors")}}</td> <td>{{Spec2("CSS2.1")}}</td> <td></td> </tr> <tr> <td>{{SpecName("CSS1", "#contextual-selectors", "contextual selectors")}}</td> <td>{{Spec2("CSS1")}}</td> <td>Initial definition</td> </tr> </tbody> </table> <h2 id="浏览器兼容性">浏览器兼容性</h2> <p>{{Compat("css.selectors.descendant")}}</p> <h2 id="相关">相关</h2> <ul> <li><a href="/en-US/docs/Web/CSS/Child_combinator">Child combinator</a></li> </ul>