CSS :required 伪类用于选择并设置必填表单元素的样式（仅适用于 、 和 </a>）。</p> <p>具有 required 属性的表单元素被定义为必填的。</p> <p class="tip"><span>提示：</span>使用 <code><a href="/ha/cssref/selector_optional.html" title="CSS :optional hukunci">:optional</a></code> 伪类选择可选表单元素。</p> </section> <section> <h2>实例</h2> <p>选择并设置任何具有 required 属性的 <input> 元素的样式。同时设置任何没有 required 属性的 <input> 元素的样式：</p> <pre class="language-css"> input:optional { background-color: lightgreen; } input:required { background-color: pink; border-color: red; } </pre> <p class="tiy"><a target="_blank" href="/ha/tiy/t.html?f=selector_required">亲自试一试</a></p> </section> <section> <h2>CSS 语法</h2> <pre class="language-css"> :required { <i>css declarations</i>; } </pre> </section> <section> <h2>技术细节</h2> <table class="technical-details"> <tr> <th style="width: 25%;">版本：</th> <td>CSS3</td> </tr> </table> </section> <section> <h2>浏览器支持</h2> <p>表格中的数字指定了完全支持该伪类的首个浏览器版本。</p> <table class="browser-support"> <tr> <th class="bsChrome">Chrome</th> <th class="bsEdge">Edge</th> <th class="bsFirefox">Firefox</th> <th class="bsSafari">Safari</th> <th class="bsOpera">Opera</th> </tr> <tr> <td>10</td> <td>10</td> <td>4</td> <td>5</td> <td>10</td> </tr> </table> </section> <section> <h2>Ɗaɗaɗon</h2> <p>Manan:<a href="/ha/cssref/selector_optional.html">CSS :optional hukunci</a></p> </section> <div class="prenextnav-ref"> <ul> <li> Ɗakin ɗaya <a href="/ha/cssref/selector_read-write.html" title="CSS :read-write hukunci">:read-write</a></li> <li> Ɗakin ɗaya <a href="/ha/cssref/selector_right.html" title="CSS :right hukunci">:right</a></li> <li> Raba ɗaya <a href="/ha/cssref/css_ref_pseudo_classes.html" title="Manufa kwarin nasa CSS">Manufa kwarin nasa CSS</a></li> </ul> </div><div style="background-color:#fcfdf8; padding:0;"> </div> </div> <!-- maincontent end --> <div id="sidebar"> <div><h3><center> Alaɗi </center><h3> <h5 id="tools_reference"><a href="/ha/cssref/index.html">Manufa kwarin CSS</a></h5> <h5 id="tools_example"><a href="/ha/css/css_examples.html">CSS hukunci</a></h5> <h5 id="tools_quiz"><a href="/ha/css/css_quiz.html">CSS tesar</a></h5> <h5 id="tools_tutorial"><a href="/ha/css/index.html">CSS yancin</a></h5> </div> <div><h3><center> Rarrabari hukunci </center><h3> <div id="sbtg"> <script src="/myjs/zzsr.js"></script> </div> </div> </div> <div id="footer"> <p id="p1"> CodeW3C.com tukuru hukunci ba hukunci, ba ga tsene tsene hukunci. Risiko ba hukunci ba hukunci ba hukunci, ba ga tsene ba hukunci. Tsene ba hukunci, tsene ba hukunci. </p> <p id="p2"> <a href="/ha/about/index.html" title="Hakkoharri CodeW3C.com">Hakkoharri CodeW3C.com</a> <a href="/ha/about/about_helping.html" title="Yanarri CodeW3C.com">Yanarri CodeW3C.com</a> <a href="/ha/about/about_use.html" title="Hakkoharri soyi">Tsene yanarri</a> <a href="/ha/about/about_privacy.html" title="Hakkoharri tsenohari">Tsene tsenohari</a> <a href="http://www.comfortsoftwaregroup.com/" target="_blank"><img src="/comfortsoftwaregroup.png"></a> <a href="http://www.ce4e.com/" target="_blank"><img src="/poweredby.png" alt="Ana ga Ce4e.com"></a> </p> </div> </div> <!-- wrapper end --> <script src="/myjs/tongji.js"></script> </body> </html>
:required