C# Regex getting words that start with?

问题

How can I use a regular expression to get words that start with ! ? For example !Test.

I tried this but it doesn't give any matches:

@"\B\!\d+\b"

Although it did work when I replaced the ! with $.

回答1:

This should work: ^!\w+

 MatchCollection matches = Regex.Matches (inputText, @"^!\w+");

 foreach (Match  match in matches)
 {
      Console.WriteLine (match.Value);
 }

回答2:

I'd say that your regex was quite OK already, you just need to use \w (alphanumeric character) instead of \d (digit):

@"\B!\w+\b"

will match any word that is immediately preceded by a ! unless that ! itself is preceded by a word itself (that's what the \B asserts). Using a ^ instead will limit the matches to words that start at the beginning of a line which might not be what you want.

So this will match all the words including exactly one preceding ! in this line:

!hello !this ...!will !!!be !matched!

but none of the words in this line:

this! won't!be matched!!! 

You could also drop the \B altogether if you don't mind matching !that in this!that.

来源：https://stackoverflow.com/questions/3952032/c-sharp-regex-getting-words-that-start-with