javascript获取网页各种高宽及位置的方法总结

screen.width     //屏幕的宽
screen.height    //屏幕的高
screen.availWidth  //屏幕可用宽度  屏幕的像素高度减去系统部件高度之后的值
screen.availHeight  //屏幕可用高度  屏幕的像素宽度减去系统部件宽度之后的值

window.screenTop   //窗口顶部距屏幕顶部的距离
window.screenLeft  //窗口左侧距屏幕左侧的距离
window.innerWidth  //窗口中可视区域(viewpoint)的宽度
  alert(window.innerWidth); //chrome 1366 ff 1366 ie 1366
window.innerHeight  //窗口中可视区域(viewpoint)的高度 该值与浏览器是否显示菜单栏等因素有关
  alert(window.innerHeight); //chrome 643 ff 657 ie 673
window.outerWidth  //浏览器窗口本身的宽度(可视区域宽度+浏览器边框宽度)
  alert(window.outerWidth); //chrome 1366 ff 1382 ie 1382 
  //说明chrome在最大化时浏览器窗口没有边框宽度,非最大化时有8px边框
  //ff和ie上下左右有8px的边框宽度
window.outerHeight  //浏览器窗口本身的高度
  alert(window.outerHeight); //chrome 728 ff 744 ie 744

boxWidth = 2*margin + 2*border + 2*padding + width
boxHeight = 2*margin + 2*border + 2*padding + height

body{margin:0;}
#demo{
  width:100px;
  height:100px;
  padding:10px;
  border:20px;
  margin:30px;
  background-color:red;
}
<div id="demo">123456789 123456789</div>

clientWidth = 2*padding + width - scrollbarWidth   
console.log(document.getElementById('demo').clientWidth); //120 此时scrollbarWidth=0
clientHeight = 2*padding + height - scrollbarHeight 
console.log(document.getElementById('demo').clientHeight); //120 此时scrollbarWidth=0

offsetWidth = 2*border + 2*padding + width 
console.log(document.getElementById('demo').offsetWidth)  //160
offsetHeight = 2*border + 2*padding + height 
console.log(document.getElementById('demo').offsetHeight)  //160

console.log(document.getElementById('demo').offsetLeft)  //30
console.log(document.getElementById('demo').offsetTop)  //30

body{
  margin:0;
  padding:20px;
  width:1000px;
  height:500px;
}
<div id="demo">123456789123456789</div>

scrollWidth = 2*padding + width  
console.log(document.body.scrollWidth)  //1040
scrollHeight = 2*padding + width  
console.log(document.body.scrollHeight)  //540