example： http://whomwah.github.io/rqrcode/

github官方：https://github.com/whomwah/rqrcode

rQRCode

A Ruby library for encoding QR Codes

rQRCode is a library for encoding QRCodes in Ruby. It has a simple interface with all the standard qrcode options. It was adapted from the Javascript library by Kazuhiko Arase.

sudo gem install rqrcode

The documentation is available over on the RubyGems website.

A quick simple example in the console:

=> require 'rubygems'
=> require 'rqrcode'
=> qr = RQRCode::QRCode.new('hello world')
>> #<RQRCode::QRCode:0x32a9 ......
=> puts qr.to_s
>>
xxxxxxx    xxxx   xxxxxxx
x     x x   xxx   x     x
x xxx x x  xx xx  x xxx x
x xxx x xx x  x   x xxx x
.....

Also, here is a quick example of using it in a Ruby on Rails project:

# Controller
require 'rqrcode'
 
def qrcode
 @qr = RQRCode::QRCode.new('hello world')
end
 
# View
<style type="text/css">
 table {
  border-width: 0;
  border-style: none;
  border-color: #0000ff;
  border-collapse: collapse;
 }
 td {
   border-width: 0;
   border-style: none;
   border-color: #0000ff;
   border-collapse: collapse;
   padding: 0;
   margin: 0;
   width: 10px;
   height: 10px;
 }
 td.black { background-color: #000; }
 td.white { background-color: #fff; }
</style>
 
<table>
 <% @qr.modules.each_index do |x| -%>
   <tr>
   <% @qr.modules.each_index do |y| -%>
    <% if @qr.dark?(x,y) -%>
    <td class="black"/>
    <% else -%>
    <td class="white"/>
    <% end -%>
   <% end -%>
   </tr>
 <% end -%>
</table>