wifi 二维码生成

小米手机的 wifi 可以生成二维码，通过扫码连接 wifi。当然，凡事都是两面性，好的方面，当然是即使忘记密码，也能让另一台手机连上网络，而且不用手输入密码；而坏的方面是，二维码是可解析的，知道二维码就知道 wifi 的密码。

二维码知识

本节内容来自 二维码知识

二维码格式

类型	说明
文本 text	直接生成，无需处理
网址 url	直接生成，无需处理（如果前缀加上 url: 在微信中不能自动跳转）
名片 mecard	MECARD:N: 小明；TEL:13723456789;EMAIL:payonesmile@qq.com;ADR: 广州天河区；ORG:xx 有限公司；URL:http://pro.wwei.cn/;NOTE:QQ：13783821;
电话 tel	tel:13723456789
邮箱 mail	mailto:payonesmile@qq.com
短信 sms	smsto:13723456789: 短信内容
无线网络 WIFI	WIFI:S:CMCC;P:123456;T:WPA/WPA2;

二维码纠错级别

纠错级别越高，生成图片会越大。

L 水平 7%的字码可被修正

M 水平 15%的字码可被修正

Q 水平 25%的字码可被修正

H 水平 30%的字码可被修正

WIFI 二维码

本节内容来自 https://github.com/zxing/zxing/wiki/Barcode-Contents

We propose a syntax like “MECARD” for specifying wi-fi configuration. Scanning such a code would, after prompting the user, configure the device’s Wi-Fi accordingly. Example:

WIFI:T:WPA;S:mynetwork;P:mypass;;

Parameter	Example	Description
T	WPA	Authentication type; can be WEP or WPA or WPA2-EAP, or nopass for no password. Or, omit for no password.
S	mynetwork	Network SSID. Required. Enclose in double quotes if it is an ASCII name, but could be interpreted as hex (i.e. “ABCD”)
P	mypass	Password, ignored if T is nopass (in which case it may be omitted). Enclose in double quotes if it is an ASCII name, but could be interpreted as hex (i.e. “ABCD”)
H	true	Optional. True if the network SSID is hidden. Note this was mistakenly also used to specify phase 2 method in releases up to 4.7.8 / Barcode Scanner 3.4.0. If not a boolean, it will be interpreted as phase 2 method (see below) for backwards-compatibility
E	TTLS	(WPA2-EAP only) EAP method, like TTLS or PWD
A	anon	(WPA2-EAP only) Anonymous identity
I	myidentity	(WPA2-EAP only) Identity
PH2	MSCHAPV2	(WPA2-EAP only) Phase 2 method, like MSCHAPV2

Order of fields does not matter. Special characters \, ;, , and : should be escaped with a backslash (\) as in MECARD encoding. For example, if an SSID was literally "foo;bar\baz" (with double quotes part of the SSID name itself) then it would be encoded like: WIFI:S:"foo\;bar\\baz";;

实现

这里就不描述如何编写的了，代码在 github 开源，下面演示一下：