Question

How can I convert the list of match result from regex into List<string>? I have this function but it always generate an exception,

Unable to cast object of type ‘System.Text.RegularExpressions.Match’
to type ‘System.Text.RegularExpressions.CaptureCollection’.

public static List<string> ExtractMatch(string content, string pattern)
{
    List<string> _returnValue = new List<string>();
    Match _matchList = Regex.Match(content, pattern);
    while (_matchList.Success)
    {
        foreach (Group _group in _matchList.Groups)
        {
            foreach (CaptureCollection _captures in _group.Captures) // error
            {
                foreach (Capture _cap in _captures)
                {
                    _returnValue.Add(_cap.ToString());
                }
            }
        }
    }
    return _returnValue;
}

If I have this string,

I have a dog and a cat.

regex

dog|cat

I want that the function will return of result into List<string>

dog
cat

Answer 1

With the Regex you have, you need to use Regex.Matches to get the final list of strings like you want:

MatchCollection matchList = Regex.Matches(Content, Pattern);
var list = matchList.Cast<Match>().Select(match => match.Value).ToList();