HTML longdesc 属性</strong>用于指定包含 iframe 元素内容的详细描述的页面。</p> <p><strong>句法：</strong> </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><Iframe longdesc="URL"> </code></pre> </div> <p><strong>属性值：</strong></p> <ul> <li> <strong>URL：</strong>它包含单个值，即<b>URL</b> ，它指定包含框架内容的长描述的页面。 <ol> <li><strong>绝对 URL：</strong>它指向另一个网站。</li> <li><strong>相对 URL：</strong>它指向网站内的文件。</li> </ol> </li> </ul> <p><strong>例子：</strong> </p> <div class="hcb_wrap"> <pre class="prism line-numbers lang-html" data-lang="HTML"><code class="replace"><!DOCTYPE html> <html> <head> <title> HTML iframe longdesc Attribute </title> </head> <body style="text-align:center;"> <h1 style="color:green;">GeeksforGeeks</h1> <h4>HTML iframe longdesc Attribute</h4> <iframe src="https://ide.geeksforgeeks.org/index.php" srcdoc="<p>GeeksforGeeks</p>" id="GFG" longdesc="gfg.txt" height="200" width="400" name="myGeeks">