这个 onfocus 属性在元素获得焦点时起作用。此事件属性主要与 、、 元素一起使用。除了 、、、、、、<meta>、<param>、<script>、<style>、和 <title> 元素。<br/><strong>支持的标签：</strong>它支持下面给出的所有 HTML 元素：</p> <ul> <li> <strong><基地></strong></li> <li> <strong><bdo></strong></li> <li> <strong><br></strong></li> <li> <strong><头></strong></li> <li> <strong><html></strong></li> <li> <strong><iframe></strong></li> <li> <strong><元></strong></li> <li> <strong><参数></strong></li> <li> <strong><脚本></strong></li> <li> <strong><样式></strong></li> <li> <strong><标题></strong></li> </ul> <p><strong>句法：</strong> </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><element onfocus = "script"></code></pre> </div> <p><strong>属性值：</strong>调用 onfocus 属性时运行的脚本值。<br/><strong>例子：</strong></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> <head> <title>onfocus attribute</title> <style> h1 { color:green; } body { text-align:center; } input { color:white; margin-top:5px; border:1px solid black; border-radius:3px; } </style> <script> function sudo(x) { document.getElementById(x).style.background = "green"; } </script> </head> <body> <h1>GeeksforGeeks</h1> <h2>onfocus event attribute</h2> First name: <input type="text" id="fname" onfocus="sudo(this.id)"><br> Last name: <input type="text" id="lname" onfocus="sudo(this.id)"> </body></code></pre> </div> <p></p> <hr/> </div> <p><strong>输出：</strong> </p> <p><img alt="" class="img-fluid" src="https://mangodoc.oss-cn-beijing.aliyuncs.com/geek8geeks/HTML_%7C_onfocus_Event_Attribute_0.jpg"/></p> <p></p> <div class="_ap_apex_ad" id="d6f45c53-ff16-4cc5-8b91-eb6ee7037116" style="min-height:280px"></div> <p></p> <p><strong>支持的浏览器：</strong> <i>onfocus</i>属性支持的浏览器如下：</p> <ul> <li>苹果Safari</li> <li>谷歌浏览器</li> <li>火狐</li> <li>歌剧</li> <li>IE浏览器</li> </ul> <div class="_ap_apex_ad" id="82d2079a-8120-480f-9fc7-5cda825d56e7" style="min-height:280px"></div> <p></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>