I have to Develop a Service (C#) which read data from Network Device via TCP Socket and convert this is C# structure.
I am basing on existing, old Delphi application which is doing all this stuff and I have to migrate logic in C#.
EDITED: I got a snapshot from C-Source of original data-structure:
struct _RequestMsgStruct
{
UCHAR request_ver; //In DELPHI it is represented as Byte
USHORT mac_addr[3]; /* MAC Address */
UINT product_type; //In DELPHI - Cardinal
UCHAR supply_type; //In DELPHI - Byte
short reserved0; //In DELPHI - SmallInt
UCHAR oper_ver[4]; //In DELPHI - CARDINAL !!!
USHORT brd_id; //In DELPHI - WORD
unsigned short exp_id1; //In DELPHI - WORD
//In DELPHI - string[15]; //Array [0..15] of char;
UCHAR serial_no[16]; /* Serial Number. 16th char have to be NULL */
UCHAR _name[32]; /* Name */ //Length of payload may vary //In DELPHI - string[31]
float data_avg; //In DELPHI - Single
ULONG key[5]; //In DELPHI - array [0..19] of Byte
}__attribute__ ((packed));
There is Delphi Packed record with over 200 fields of different types... it look approximately like:
TREC_DATA = packed record
ID : Byte;
MAC_ADDRESS : array [0..5] of Byte;
fieldCard : cardinal;
fieldSI : SmallInt;
fieldW : WORD;
SERIAL_NUMBER : string[15]; //Array [0..15] of char;
fieldSingle : Single;
fieldArrOfB : array [0..19] of Byte;
end;
To move byte array to structure in Delphi there is next code:
Move(inBytesArr[StartIdx], DelphiStruct, aMsgSize)
To convert string files (eg SERIAL_NUMBER) there is also such code:
var
pc: Pchar;
...
pc := @inBytesArr[StartIdx + SerialN_Pos_Idx];
DelphiStruct.SERIAL_NUMBER := pc;
I having deal with such conversion for first time and I don't know from where to start:
How to convert this structure to c#? -- Should I use LayoutKind.Sequential
or LayoutKind.Explicit
, with or wiyhout [FieldOffset(N)]
attribute? -- How I have to declare array of bytes in target c# structure: as fixed
buffer or using [MarshalAs(UnmanagedType.ByValArray...)]
attribute?
Which is better way to marshal input bytes array to final C# structure: using Marshal.PtrToStructure
or GCHandle.Alloc(bytes, GCHandleType.Pinned) + AddrOfPinnedObject
?
Please help me, at least, to get start point in understating from where i need to start.
By default, Delphi's packed records align fields by single byte boundary.
Hence, you should use something like this:
[StructLayout(LayoutKind.Sequential, Pack = 1)]
struct TREC_DATA
{
public byte ID;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 6)]
public byte[] MAC_ADDRESS;
public uint fieldCard;
public short fieldSI;
public ushort fieldW;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
public byte[] SERIAL_NUMBER;
public float fieldSingle;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 10)]
public byte[] fieldArrOfB;
}
The only thing I'm not sure (and can't test now without Deplhi), is a SERIAL_NUMBER field.
After your update: in original, SERIAL_NUMBER is just a null-terminated string.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.