extern public static int BS2_ScanFingerprint(IntPtr context, UInt32 deviceId, ref BS2Fingerprint finger, UInt32 templateIndex, UInt32 quality, byte templateFormat, OnReadyToScan cbReadyToScan);
extern public static int BS2_ScanCard(IntPtr context, UInt32 deviceId, out BS2Card card, OnReadyToScan cbReadyToScan);