使用正则表达式在C＃中用字符转义字符串的一部分

Question

I have a string such as this:

/one/two/three-four/five six seven/eight/nine ten eleven-twelve

I need to first replace dashes with spaces, and then be able to escape any grouping of words that have a space between them with a "#" symbol, so the above string should be:

/one/two/#three four#/#five six seven#/eight/#nine ten eleven twelve#

I have the following extension method which works great for two words, but how can I make it work for any number of words.

 public static string QueryEscape(this string str)
    {
        str = str.Replace("-", " ");
        return Regex.Replace(str, @"(\w*) (\w*)", new MatchEvaluator(EscapeMatch));
    }

private static string EscapeMatch(Match match)
    {
        return string.Format("#{0}#", match.Value);
    }

So I guess I really need help with the proper regex that takes into account that

1. there could be any number of spaces
2. there may or may not be a trailing slash ("/")
3. takes into account that words are grouped between slashes, with the exception of #2 above.
4. Dashes are illegal and need to replaced with spaces

Thank you in advance for your support.

Answer 1

This should work for you:

public static string QueryEscape(this string str)
{
    return Regex.Replace(str.Replace("-", " "), @"[^/]*(\s[^/]*)+", "#$&#");
}

Basically the idea is to match spans of text that isn't a slash that contains a (white-)space character in it. Then add the pound signs around the match.