C#正則表達式根據分組命名取值

string[] regexList = new string[] {
                @"^(?<TickerPart1>[0-9A-Z])[ 0_]?(?<TickerPart2>[A-Z][0-9]) ?(COM(DTY)?|INDEX|IDX|IND|CURNCY|CUR|CLQ|ILQ|IDS)$",
                @"^(?<Ticker>[0-9A-Z]{2,5}[A-Z][0-9]) ?(COM(DTY)?|INDEX|IDX|IND|CURNCY|CUR)$",
                @"^(?<Ticker>[0-9A-Z]{2,5}[A-Z][0-9])$",
            };
string externalId = "3ABZ9 COMDTY";
//測試例子
//A Z9 INDEX;AZ9 CUR;A_H9 IDX;A0H9COM;ABZ9 INDEX;3ABZ9 COMDTY;ABZ9;3ABZ9
foreach (string regexString in regexList)
{
    if (Regex.IsMatch(externalId, regexString, RegexOptions.IgnoreCase))
    {
        Regex reg = new Regex(regexString, RegexOptions.IgnoreCase);
        Match mc = reg.Match(externalId);
        GroupCollection groups = mc.Groups;
        string convertid = "";
        foreach (string grn in reg.GetGroupNames())
        {
            if (grn.Contains("Ticker"))
　　　　　　　　　 convertid += groups[grn].Value;
        }
        Console.WriteLine(convertid);
        break;
    }
}
Console.ReadLine();

以上例子將正則表達式中所有已經命名了的分組提取出來，此外，還可以利用正則表達式的Replace方法巧妙地將特定分組提取出來：

string result = "";
string id = "1234";
string reg = @"^(?<ticker>\d{4})$";
Regex regex = new Regex(reg);
if (regex.IsMatch(id))
{
    result = Regex.Replace(id, reg, "${ticker}");
}
Console.WriteLine(result);
Console.ReadLine();