打字稿活动元素焦点

Question

我有一个带有类名称为"音乐会landing-synopsis'的部分。我已经浏览了这里的一些解决方案，重点变量始终是false

let activateElement = document.getElementsByClassName("concert-landing-synopsis");
if (activateElement.length > 0) {
  window.onscroll = _ => {
    let isFocused = (document.activeElement === activateElement[0]);
    if (isFocused) {
      console.log("On focus");
    }
  };
}

视图是这样的

<section class="concert-landing-details">
  <div></div>
  <div></div>
  <div></div>
  <div></div>
</section>

Answer 1

您需要循环浏览document.getElementsByClassName('concert-landing-synopsis')返回的所有元素，如

document.getElementsByClassName('concert-landing-synopsis').forEach((el) => {
   const isFocused = (document.activeElement === el);
});