document.body、document.documentElement和window获取视窗大小的区别

男娘i 2022-08-13 00:36 150阅读 0赞

来源：[http://www.ido321.com/906.html][http_www.ido321.com_906.html]

在w3school关于[window对象][window]的介绍中，介绍了获取浏览器窗口大小的三种方法（浏览器的视口，不包括工具栏和滚动条）。

对于Internet Explorer、Chrome、Firefox、Opera 以及 Safari：

*  window.innerHeight – 浏览器窗口的内部高度
 *  window.innerWidth – 浏览器窗口的内部宽度

对于 Internet Explorer 8、7、6、5：

*  document.documentElement.clientHeight
 *  document.documentElement.clientWidth

或者

*  document.body.clientHeight
 *  document.body.clientWidth

实用的 JavaScript 方案（涵盖所有浏览器）：

1: var w=window.innerWidth

2: || document.documentElement.clientWidth

3: || document.body.clientWidth;

5: var h=window.innerHeight

6: || document.documentElement.clientHeight

7: || document.body.clientHeight;

返回的都是数值，不带单位。这是共同点。好，接下来，看看他们的区别

1: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

2: <html xmlns="http://www.w3.org/1999/xhtml">

3: <head>

4: <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

5: <title>无标题文档</title>

6: <style type="text/css">

7: .test

8: {

9:     width:100px;

10:     height:100px;

11:     background:red;

12: }

13: #data

14: {

15:     width:200px;

16:     height:100px;

17: }

18: </style>

19: </head>

20:

21: <body>

22: <div class="test">test</div>

23: <div id="data"></div>

24: </body>

25: </html>

js代码

1: var w=window.innerWidth

2: || document.documentElement.clientWidth

3: || document.body.clientWidth;

4: var h=window.innerHeight

5: || document.documentElement.clientHeight

6: || document.body.clientHeight;

8: var data = document.getElementById('data');

9: data.innerHTML = "正常文档流情况："+"<br/>";

10: data.innerHTML += "w="+w+"<br/>";

11: data.innerHTML += "h="+h+"<br/>";

12: data.innerHTML += "document.body.clientHeight="+document.body.clientHeight+"<br/>";

13: data.innerHTML += "document.body.clientWidth="+document.body.clientWidth+"<br/>";

14: data.innerHTML += "window.innerWidth="+window.innerWidth+"<br/>";

15: data.innerHTML += "window.innerHeight="+window.innerHeight+"<br/>";

16: data.innerHTML += "document.documentElement.clientHeight="+document.documentElement.clientHeight+"<br/>";

17: data.innerHTML += "document.documentElement.clientWidth="+document.documentElement.clientWidth+"<br/>";

看看结果输出：（ps：电脑分辨率是1366\*768）

![SouthEast][]![SouthEast 1][]![SouthEast 2][]

给.test添加左浮动：float:left，让其脱离正常文档流，看看结果：

![SouthEast 3][]![SouthEast 4][]![SouthEast 5][]

除了document.body.clientHeight变成了100，其他基本保持不变。

但是给.data也添加float:left，在对应的浏览器中，document.body.clientHeight变成了0，其他基本保持不变。不信可以自己试试。

关于JavaScript中的\*top、\*left、\*width、\*Height详解：[http://www.ido321.com/911.html][http_www.ido321.com_911.html]

[http_www.ido321.com_906.html]: http://www.ido321.com/906.html
[window]: http://www.w3school.com.cn/js/js_window.asp
[SouthEast]: https://img-blog.csdn.net/20141003230836640?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMTA0Mzg0Mw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
[SouthEast 1]: https://img-blog.csdn.net/20141003231018661?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMTA0Mzg0Mw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
[SouthEast 2]: /images/20220810/c17064786d654ea7b01f8c39cc66423f.png
[SouthEast 3]: https://img-blog.csdn.net/20141003230923984?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMTA0Mzg0Mw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
[SouthEast 4]: https://img-blog.csdn.net/20141003230932187?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMTA0Mzg0Mw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
[SouthEast 5]: /images/20220810/624cdd58e3244f4484006113a49f8073.png
[http_www.ido321.com_911.html]: http://www.ido321.com/911.html