前端BOM常用操作

BOM操作常用命令详解及代码案例

BOM（Browser Object Model）是浏览器对象模型，是浏览器提供的JavaScript操作浏览器的API。BOM提供了与网页无关的浏览器的功能对象，虽然没有正式的标准，但现代浏览器已经几乎实现了JavaScript交互性方面的相同方法和属性，因此常被认为是BOM的方法和属性。本文将详细介绍BOM操作中的常用命令，并通过代码案例进行解释。

1. 获取浏览器窗口尺寸

获取可视窗口宽度：window.innerWidth
获取可视窗口高度：window.innerHeight

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><script>javascript">var m1 = window.innerWidth;var m2 = window.innerHeight;console.log(m1);console.log(m2);</script>
</body>
</html>

2. 浏览器的弹出层

提示框：window.alert('提示信息')
询问框：window.confirm('提示信息')
输入框：window.prompt('提示信息', '默认值')

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><script>javascript">// window.alert('你好!')// var res = window.confirm('你好吗?')// console.log(res)var res2 = window.prompt('你是哪个省的?');console.log(res2);</script>
</body>
</html>

3. 开启和关闭标签页

开启：window.open('地址')
关闭：window.close()

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><button id="on">开启</button><button id="off">关闭</button><script>javascript">var on = document.getElementById('on');var off = document.getElementById('off');on.onclick = function() {window.open('https://www.baidu.com/');}off.onclick = function() {window.close();}</script>
</body>
</html>

4. 浏览器常见事件

资源加载完毕：window.onload = function() {}
可视尺寸改变：window.onresize = function() {}
滚动条位置改变：window.onscroll = function() {}

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><img src="图片链接" alt=""><script>javascript">window.onload = function() {console.log('资源已经加载完毕');}window.onresize = function() {console.log('可视尺寸改变');}window.onscroll = function() {console.log('滚动条位置改变');}</script>
</body>
</html>

5. 浏览器的历史记录操作

回退页面：window.history.back()
前进页面：window.history.forward()
跳转到指定页面：window.history.go(n)，其中n可以是负数（表示后退）或正数（表示前进）

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><button onclick="goBack()">回退</button><button onclick="goForward()">前进</button><button onclick="goToPage(-2)">回退两页</button><script>javascript">function goBack() {window.history.back();}function goForward() {window.history.forward();}function goToPage(n) {window.history.go(n);}</script>
</body>
</html>

6. 浏览器卷去的尺寸和滚动

卷去的高度：document.documentElement.scrollTop 或 window.scrollY
卷去的宽度：document.documentElement.scrollLeft 或 window.scrollX
滚动到指定位置：window.scrollTo(left, top) 或 window.scrollTo({left: xx, top: yy, behavior: 'smooth'})

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><style>body {width: auto;height: 3000px;}button {position: fixed;bottom: 50px;right: 50px;}</style>
</head>
<body><button id="go">传送</button><script>javascript">var go = document.getElementById('go');go.onclick = function() {window.scrollTo({left: 300, top: 400, behavior: "smooth"});}</script>
</body>
</html>

7. Navigator对象

Navigator对象包含有关浏览器的信息。

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><script>javascript">console.log('浏览器品牌', navigator.appName);console.log('浏览器版本', navigator.appVersion);console.log('用户代理', navigator.userAgent);console.log('操作系统', navigator.platform);</script>
</body>
</html>