正则表达式匹配有效的命名空间名称
我想这个问题被问过，但我想谷歌，但没有找到答案。也许我用错了关键字。
I thought this question was asked before but I tried Google but didn't find an answer. Maybe I used wrong keywords.
时有可能使用正则表达式匹配有效的C＃命名空间名称？
Is it possible to use regular expression to match valid C# namespace name?
谢谢
更新：
谢谢大家对你的答案和研究！这个问题要复杂得多比我的预期。由于奥斯卡Mederos 和乔伊指出，一个有效的命名空间不能包含C＃保留关键字，并且可以包含更多的Unicode字符不是拉丁字母。
Thanks everyone for your answers and research! This question is much more complex than I expected. As Oscar Mederos and Joey pointed out, a valid namespace cannot contain C# reserved keywords, and can contain a lot more Unicode characters than Latin letters.
但我当前的项目只需要以语法验证命名空间。所以我接受 primfaktor 的答案，但我upvoted所有的答案。
But my current project only need to syntactically validate namespaces. So I accepted primfaktor's answer, but I upvoted all answers.
对于我来说，这个工作：
For me, this worked:
^using (@?[a-z_A-Z]\w+(?:\.@?[a-z_A-Z]\w+)*);$
它匹配使用C＃行并返回第一个（也是唯一一个）匹配组完整的命名空间。您可能需要删除 ^ 和 $ ，以便缩进和尾随注释。
It matches using lines in C# and returns the complete namespace in the first (and only) match group. You may want to remove ^ and $ to allow for indentation and trailing comments.
Example on RegExr.