我想用ruby on rails生成二维码，在我用rails编写的网站后台运行。看到这个http://code.google.com/p/qrcode-rails/但我不知道如何让它为我工作。基本上，在RoR中，我想：
向生成器传递一个字符串、我的唯一代码和一个20个字符长的数字（例如3203292888998887776），然后生成一个名为_qr.jpg的图像，并将其保存在资源文件夹中，以附加到我的程序将发送的电子邮件中。
我该怎么做，有人知道吗？
当我问（我现在得到这个答案并不重要），但我该如何实现二维码读取，从网络摄像头中取回二维码？谢谢
如果您只需要将数据从URL写入文件，您可以打开一个流，从文件中读取数据，然后简单地将数据写入磁盘——只需记住使用相同的扩展名（在本例中为.jpg）
请注意，您也可以简单地在电子邮件中发送链接（或将其作为内联图像发布在电子邮件中。）如果您真的非常想将其写入磁盘并在生产系统中作为附件发送，那么Ruby图像处理的一流解决方案是Ruby vips或ImageMagick。
最后，由于这是一个磁盘操作，您将希望在正常的web请求周期之外进行操作——您可能最好使用delayed_job来完成操作，或者至少使用AJAX请求来触发进程。这两种方法都为您提供了一个优势，即您可以为操作提供进度条。
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