HTML autofocus 属性用于指定在页面加载时 元素应该获得焦点。它是一个布尔属性。 注意：它仅支持以下元素：、、 和 </p> <p><strong>句法：</strong> </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><keygen autofocus></code></pre> </div> <p><strong>示例：</strong>下面的示例说明了 <keygen> 元素的 autofocus 属性。</p> <div> <h5 class="code">HTML</h5> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><!DOCTYPE html> <html> <body style="text-align: center;"> <h1 style="color:green;"> GeeksforGeeks </h1> <h2>HTML Keygen autofocus attribute</h2> <form> Username: <input type="text" name="uname"> <br><br> Encryption: <keygen form="myGeeks" name="secure" autofocus> <input type="submit"> </form> </body> </html></code></pre> </div> <p></p> <hr/> </div> <p><strong>输出：</strong> </p> <p><img class="img-fluid" sizes="100vw" src="https://mangodoc.oss-cn-beijing.aliyuncs.com/geek8geeks/HTML_<keygen>_autofocus_Attribute_0.jpg" srcset="https://media.geeksforgeeks.org/wp-content/uploads/20210413135453/gmail-660x376.png 660w, https://media.geeksforgeeks.org/wp-content/uploads/20210413135453/gmail-768x438.png 768w, https://media.geeksforgeeks.org/wp-content/uploads/20210413135453/gmail.png," width="300"/></p> </div> </article> </div> </div> </div> </div> </div> <footer> <div class="bg-white text-center pb-1"> <p class="text-body-tertiary pt-3 lh-lg text-opacity-50" id="footer-text">Copyright © 2020 - 2024 版权所有 <br> <a href="https://beian.miit.gov.cn/" target="_blank" class="text-opacity-50 text-body-tertiary mt-1 mb-1">蜀ICP备20006366号-1</a> <br> Made with ❤️ in Chengdu </p> </div> </footer> <!-- 引入Bootstrap JavaScript库 --> <script src="https://unpkg.com/bootstrap@5.3.0-alpha1/dist/js/bootstrap.bundle.min.js" crossorigin="anonymous"></script> <!-- 引入Meilisearch搜索相关的JavaScript库 --> <script src="https://cdn.jsdelivr.net/npm/@meilisearch/instant-meilisearch/dist/instant-meilisearch.umd.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/instantsearch.js@4"></script> <script src="https://imangodoc.com/static/javascript/meili_custom.js"></script> <!-- 引入prismjs代码高亮相关的JavaScript库 --> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-core.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/toolbar/prism-toolbar.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/autoloader/prism-autoloader.min.js"></script> <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/copy-to-clipboard/prism-copy-to-clipboard.min.js"></script> </body> </html>