public virtual GroupCollection Groups { get; }

Group 型別 GroupCollection屬性(索引)：Item[String] 允許通過字串索引訪問集合成員。
Group型別定義：

[SerializableAttribute]
public class Group : Capture

Capture 類：表示單個成功的子表示式捕獲的結果。

string result = "{\"access_token\":\"FQSRXOwxRELZLN9ZfRXm2tWiVajEuk7pesRI74vCrH8sfqL4XqX2_aT_HZOLTmgD5_4s884sYVpBqtZDFNAc1EQTJ84aZTj5GDP7wVg0BgoYoWffgmTQMNik1HtC7mVjzbuYdMzhJxFx - sL6SbodMfd_Yzq_iwuy6rW4Myg0zLsQFKSoyCCHCsIOEzcFI9geKXqvVe8uNQomEhewRQt40Q\",\"
 
expires_in\":7200}";
string regex = "\"access_token\":\"(?<token>.*?)\"";

string token = CRegex.GetText(result, regex, "toke");


public static string GetText(string sInput, string sRegex, string sGroupName)
{
    Regex re = new Regex(sRegex, RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace | RegexOptions.Multiline);
    Match mc = re.Match(sInput);
    string
 
 result = "";
    if (mc.Success)
    {
        if (sGroupName != "")
        {
            result = mc.Groups[sGroupName].Value;
        }
        else
        {
            result = mc.Value;
        }
    }
    return result;
}