开发/运行时C＃类库的许可机制？

I'm developing a .Net class library (a data provider) and I'm starting to think about how I would handle licensing the library to prospective purchasers. By licensing, I mean the mechanics of trying to prevent my library from being used by those who haven't purchased it, not the software license (i.e., Apache, Gnu, etc).I'm developing a .Net class library (a data pro