造轮子-组件库-获取元素框高判断可视区域

获取元素框高

1. offsetTop < clientHeight + scrollTop
2. element.getBoundingClientRect().top < clientHeight
3. IntersectionObserver

1. window.getComputedStyle() element.currentStyle
2. offsetHeight、offsetWidth、offsetTop、offsetLeft、officeParent
3. clientWidth、clientHeight
4. scrollHeight、 scrollWidth、 scrollTop、 scrollLeft
5. getBoundingClientRect()