public static string GetYouTubeStandardChannelId(this string str)
{
if (str == null)
{
return(null);
}
var match = YouTubeChannelIdRegex.Match(str);
if (!match.Success || match.Groups["id"].Captures.Count != 1)
{
return(null);
}
return(match.Groups["id"].Captures[0].Value);
}
// Extension methods
public static bool IsValidYouTubeChannelUrl(this string str)
{
return(YouTubeChannelIdRegex.IsMatch(str));
}