javascript 这是一个JS函数，用于查找元素相对于窗口的顶部和左侧偏移量

Posted 2021-05-03

// Notes for the findPos function:

// * This does *not* work on objects with
// position: fixed, as such objects don't
// have offset parents!!!

// * Be sure to feed target[0] into this,
// rather than just target!!!
function findPos(obj) {
  var curleft = 0;
  var curtop = 0;
  if (obj.offsetParent) {
    do {
      curleft += obj.offsetLeft;
      curtop += obj.offsetTop;
    } while ((obj = obj.offsetParent));
    return [curleft, curtop];
  }
}