Extract Matching Group Names: Cleaner way to do it?

Question

Suppose I have a pattern in the form of "((?<happy>foo)|(?<sad>bar)|...)" . There could be many more conditions. If I wanted to know which grouping I had found (e.g. searching 12bar34 will return "sad", is there a cleaner way to do it than the code I have now?

Regex objRegex = new Regex("((?<happy>foo)|(?<sad>bar))");
Match objMatch = objRegex.Match("12bar34");        
for (int i = 0; i < objMatch.Groups.Count; ++i)
{
    int tmp;
    if (!String.IsNullOrEmpty(objMatch.Groups[i].Value) &&
        !Int32.TryParse(objRegex.GroupNameFromNumber(i), out tmp))
    {
        //The name of the grouping.
        Trace.WriteLine(objRegex.GroupNameFromNumber(i));
    }
}

Answer 1

foreach(string groupName in objRegex.GetGroupNames())
{
   if (objMatch.Groups[groupName].Success)
      Trace.WriteLine(groupName);
}

Note though that that Regex.GetGroupNamesalso considers "0" to be a group (the entire match), so you may need to filter that out if you don't want it.