npm中的js库很全面，但一般是用于node.js环境中的。
有些时候，我们想在浏览器环境中，直接使用npm的库，怎么办呢？
至少有两种方法：
- 方案1：走webpack等打包工具
- 方案2：走browserify
本文主要介绍方案2，browerify的方案更简单，很好操作。
1、安装browerify
cnpm install -g browserify
cnpm install -g browserify
cnpm install -g browserify
2、安装npm库
需要先通过npm安装下，比如这里，我们想使用这个库
cnpm i sm-crypto
cnpm i sm-crypto
cnpm i sm-crypto
3、编写适配脚本
main.js
var sm4 = require('sm-crypto').sm4
global.window.sm4 = sm4
var sm4 = require('sm-crypto').sm4
global.window.sm4 = sm4
var sm4 = require('sm-crypto').sm4
global.window.sm4 = sm4
4、执行browerify
browserify main.js -o bundle.js
browserify main.js -o bundle.js
browserify main.js -o bundle.js
生成的bundle.js就可以直接用了，我们看下用法：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script src="./bundle.js"></script>
</head>
<body>
<div id="app1"></div>
<div id="app2"></div>
<script>
let sm4 = window.sm4
const msg = 'hello world! .'
const key = '0123456789abcdeffedcba9876543210'
let encryptData = sm4.encrypt(msg, key)
document.getElementById("app1").innerHTML = encryptData
document.getElementById("app2").innerHTML = sm4.decrypt(encryptData, key)
</script>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script src="./bundle.js"></script>
</head>
<body>
<div id="app1"></div>
<div id="app2"></div>
<script>
let sm4 = window.sm4
const msg = 'hello world! .'
const key = '0123456789abcdeffedcba9876543210'
let encryptData = sm4.encrypt(msg, key)
document.getElementById("app1").innerHTML = encryptData
document.getElementById("app2").innerHTML = sm4.decrypt(encryptData, key)
</script>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script src="./bundle.js"></script>
</head>
<body>
<div id="app1"></div>
<div id="app2"></div>
<script>
let sm4 = window.sm4
const msg = 'hello world! .'
const key = '0123456789abcdeffedcba9876543210'
let encryptData = sm4.encrypt(msg, key)
document.getElementById("app1").innerHTML = encryptData
document.getElementById("app2").innerHTML = sm4.decrypt(encryptData, key)
</script>
</body>
</html>
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