如何创建25个字符的产品密钥

大家好

在为App创建产品密钥时，我需要您的帮助，该想法是通过创建25个字符的产品密钥来保护App的安全，该产品密钥在输入文本框时将在输入时自动添加破折号.就像传统的Microsoft Office产品密钥一样. 另外，我想知道如何创建试用版密钥和完整版密钥.

I need your help on creating a product key for App, the idea is secure the App by creating a 25-character product key which when entered into a text box dashes will automatically be added as you type. Just as the traditional Microsoft Office Product key. Also, I would like to know how I can create trial keys as well as full-version keys.

我希望此处的信息很清楚，请向我提供工作示例和/或示例代码.

I hope the message herein is clear, please provide me with working examples and/or sample codes.

任何人请回答.

预先感谢. 

Thanks in advance.