Delphi >> DLL >> C++

[Blazej]

Hi,

I have a problem using a dll written i C++ invoking from Delphi6.
How to pass pointers (type struct) to a dll ?

C++ function:

Code:

typedef struct
{       unsigned int lengt;
   unsigned char data[2096];
}MESSAGE_;

extern "C" __declspec(dllexport)
unsigned char WINAPI build_esco_format
  (MESSAGE_ *pntr,
   unsigned char comm_type,
   unsigned long source,
   unsigned long destination)

-------------------------------
Delphi function:

Delphi-Quellcode:

TYPE pMESSAGE = ^TMESSAGE_;
     TMESSAGE_ = record
     lengt: Word;
     data: Array[0..2096-1] of Char;
     end {MESSAGE};
var Message_2   : pMESSAGE;

function build_esco_format
  (Message_2 : pMESSAGE;
   comm_type : Byte;
   source    : LongInt;
   destinatin: LongInt  ): Byte;
   stdcall; external thedll;

[edit=sakura] Code-Tags corrected Mfg, sakura[/edit]

[scp]

Simply use the @ operator:

Delphi-Quellcode:

var
  AMessage : TMESSAGE_;
  Acomm_type : Byte;
  Asource    : LongInt;
  Adestination: LongInt;
  ARes :Byte;
begin
  //...
  ARes := build_esco_format(@AMessage, Acomm_type, Asource, Adestination);

[Robert Marquardt]

Delphi-Quellcode:

TYPE
  pMESSAGE = ^TMESSAGE_;
  TMESSAGE_ = packed record
     length: Integer;
     data: Array[0..2096-1] of Char;
  end {MESSAGE};