关于javascript:js-判断元素是否在可视区域

 isElementInViewport(el) {      // 获取元素是否在可视区域      var rect = el.getBoundingClientRect();      return (        rect.top >= 0 &&        rect.left >= 0 &&        rect.bottom <=          (window.innerHeight || document.documentElement.clientHeight) &&        rect.right <=          (window.innerWidth || document.documentElement.clientWidth)      );    },//应用 const keyDiv = document.getElementById("xxxld"); this.isElementInViewport(keyDiv)