javascript - 使用 Lazysizes 加载 iframe 时 document.getElementById 为 null

Question

我试图获取延迟加载的 iframe Id，但失败并出现 TypeError n is null。我错过了什么？

$(document).ready(function() {
  var widgetIframe = document.getElementById('sclazy');
  console.log(widgetIframe);
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.0/jquery.min.js"></script>
<iframe id="sclazy" height="500" width="500" frameborder="0" allow="autoplay" class="lazyload" allowfullscreen="" data-src="https://w.soundcloud.com/player/?url=https://api.soundcloud.com/tracks/188612777&auto_play=false&buying=false&sharing=false&download=true&single_active=true&hide_related=true&show_comments=true&show_user=false&show_reposts=false&show_teaser=false&visual=true&show_artwork=true">
</iframe>

Answer 1

有相同的 pb，但我做了两次，如下所示:

var iframeElement   = document.querySelector('iframe');
var iframeElementID = iframeElement.id;