JS 获取页面尺寸的方法详解

function getPageHeight() {
  var g = document,
    a = g.body,
    f = g.documentElement,
    d = g.compatMode == "BackCompat" ? a : g.documentElement;
  return Math.max(f.scrollHeight, a.scrollHeight, d.clientHeight);
}

function getPageScrollLeft() {
  var a = document;
  return a.documentElement.scrollLeft || a.body.scrollLeft;
}

function getPageScrollTop() {
  var a = document;
  return a.documentElement.scrollTop || a.body.scrollTop;
}

function getPageViewWidth() {
  var d = document,
    a = d.compatMode == "BackCompat" ? d.body : d.documentElement;
  return a.clientWidth;
}

function getPageViewHeight() {
  var d = document,
    a = d.compatMode == "BackCompat" ? d.body : d.documentElement;
  return a.clientHeight;
}

function getPageWidth() {
  var g = document,
    a = g.body,
    f = g.documentElement,
    d = g.compatMode == "BackCompat" ? a : g.documentElement;
  return Math.max(f.scrollWidth, a.scrollWidth, d.clientWidth);
}