高手请进。delphi 调用 VC写的DLL问题

Question

我用delphi调用VC写的DLL，但是VC头文件的声明union不知道在delphi中如何声明，头文件如下：
struct recCConnect
{
int  nSeqId; char sSrcAddr[ 6+1 ];
u_char usAuthSp[ 16 ];
u_char ucVersion;
int  nTimeStamp;
};
typedef struct recCConnect RecCConnect;
typedef struct recCConnect RecCConnRqst;
struct recCConnectRep
{
int  nSeqId; u_char ucStatus;
u_char usAuthIsmg[ 16 ];
u_char ucVersion;
};
typedef struct recCConnectRep RecCConnectRep;
typedef struct recCConnectRep RecCConnRep;
/* 2. Terminate */struct recCTerminate
{
int  nSeqId;
};
typedef struct recCTerminate RecCTerminate;
typedef struct recCTerminate RecCTermRqst;struct recCTerminateRep
{
int  nSeqId;
};
typedef struct recCTerminateRep RecCTerminateRep;
typedef struct recCTerminateRep RecCTermRep;typedef struct {
int     nCmdId;    // command id
union{
            RecCConnect      recConnect;
            RecCConnectRep  recConnectRep;
            RecCTerminate    recTerminate;
            RecCTerminateRep recTerminateRep;
} pkg;
u_char ucaBuff[ MacMaxBufferLen ];
} RecCCMPPPacket;有请高手以教我，谢谢！

Answer 1

举个例子：
  _LARGE_INTEGER = record
    case Integer of
    0: (
      LowPart: DWORD;
      HighPart: Longint);
    1: (
      QuadPart: LONGLONG);
  end;你的代码翻译之后：
type 
recCConnect=packed record
nSeqId:integer;
sSrcAddr:array[0..6] of char;
usAuthSp[0..15]:of char;
ucVersion:char;
nTimeStamp:integer;
end; RecCConnRqst=recCConnect ;
recCConnectRep=packed record
nSeqId:integer;
ucStatus:char;
usAuthIsmg:array[0..15] of char;
ucVersion:byte;
end;
RecCConnRep=recCConnectRep ;
(* 2. Terminate *) recCTerminate=packed record
nSeqId:integer;
end;

RecCTermRqst=recCTerminate ; recCTerminateRep=packed record
nSeqId:integer;
end;
RecCTermRep=recCTerminateRep ;
RecCCMPPPacket=packed record{
nCmdId:integer;    // command id
pkg:packed record
case integer of 
    0:
    (
     recConnect:RecCConnect;      
       );
       1:
    (
     RecCConnectRep:recConnectRep;      
       );
       2:
    (
     RecCTerminate:recTerminate;      
       );
       3:
    (
     RecCTerminateRep:recTerminateRep;      
       );
       end;
end;
ucaBuff:array[0..MacMaxBufferLen-1 ] of char;
end;