纯香草味,检查元素是否( el )在可滚动div中可见( holder )

function isElementVisible (el, holder) {
  holder = holder || document.body
  const { top, bottom, height } = el.getBoundingClientRect()
  const holderRect = holder.getBoundingClientRect()

  return top <= holderRect.top
    ? holderRect.top - top <= height
    : bottom - holderRect.bottom <= height
},

使用jquery:

var el = $('tr:last').get(0);
var holder = $('table').get(0);
isVisible =  isScrolledIntoView(el, holder);