Подключение неуправляемого кода

 [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public unsafe struct auth_answer
        {
            public OpetationTypes TType { get; set; }
            public uint  Amount { get; set; }
            public fixed byte RCode[3];
            public fixed byte AMessage[16];
            public int CType { get; set; }
            public IntPtr check;            
        }
 
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
        public unsafe struct auth_answer5
        {
            public auth_answer auth_answ;
            public fixed byte RRN[MAX_REFNUM];
            public fixed byte AuthCode[MAX_AUTHCODE];
         }
 
         [DllImport(".\\WIN\\pilot_nt.DLL", EntryPoint = "_card_authorize5", CallingConvention = CallingConvention.StdCall)]
        private static extern int card_authorize5(string truck,ref auth_answer5 InStrict);

chequeSTR = Marshal.PtrToStringAnsi(Auth_answer.auth_answ.check);

[DllImport("msvcrt.dll", CallingConvention = CallingConvention.Cdecl)]
        public static extern int _controlfp(int newControl, int mask);

const int _RC_NEAR = 0x00000000;
        const int _PC_53 = 0x00010000;
        const int _EM_INVALID = 0x00000010;
        const int _EM_UNDERFLOW = 0x00000002;
        const int _EM_ZERODIVIDE = 0x00000008;
        const int _EM_OVERFLOW = 0x00000004;
        const int _EM_INEXACT = 0x00000001;
        const int _EM_DENORMAL = 0x00080000;
        const int _CW_DEFAULT = _RC_NEAR + _PC_53 + _EM_INVALID + _EM_ZERODIVIDE + _EM_OVERFLOW + _EM_UNDERFLOW + _EM_INEXACT + _EM_DENORMAL;

_controlfp(_CW_DEFAULT, 0xfffff);