private string GetB64SessionToken(string b64encoded) { var obj = new SessionViewStateHistoryItemMarshal(b64encoded); string ndc_serialized = SerializersHelper.NetDataContractSerializer_serialize(obj); Regex b64SessionTokenPattern = new Regex(@"\<s[^>]+>([^<]+)"); Match b64SessionTokenMatch = b64SessionTokenPattern.Match(ndc_serialized); return(b64SessionTokenMatch.Groups[1].Value); }