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Help me with create .dll and .so

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xinyiman:
Suppose I have a dll in the same folder as the software, called miadll.dll and which contains the procedure MiaProcedura (PtrMiaLista MiaLista *);

Correctly filled with dev-cpp. As I recall from lazarus?

xinyiman:
Then the dll that I wrote with Devcpp function is declared as follows:

EXTERN_C __declspec(dllexport) VOID GetListaDSN (PtrListaODBC * MiaLista);

Instead PtrListaODBC is declared:

typedef struct ListaODBC
{
   char dsn[256];
    char desc[256];
   struct ListaODBC * next;
}PtrListaODBC;


In my example below I tried to interact with lazarus dll. No crashes when I run, but I do not return the result I expect! How do I change it?


unit Unit1;

{$mode objfpc}{$H+}
{$ifdef unix}
{$linklib myfunc}
{$endif}

interface

uses
  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  ExtCtrls, StdCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;

  type
   PtrListaODBC = record
     dsn : PChar;
     desc : PChar;
     next: integer;
  end;




var
  Form1: TForm1;

function GetListaDSN(MiaLista: PtrListaODBC): PChar; cdecl; external {$ifdef windows} 'ProgettoDLLODBC.dll'{$endif};

implementation

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
var
   app: PtrListaODBC;
begin
     GetListaDSN(app);
     Edit1.Text:=app.dsn;
end;

initialization
  {$I unit1.lrs}

end.
       

xinyiman:
I changed the source but now crashes when I try to exploit the variable valore with the DSN list!  :o :o

unit Unit1;

{$mode objfpc}{$H+}
{$ifdef unix}
{$linklib myfunc}
{$endif}

interface

uses
  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  ExtCtrls, StdCtrls;

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;

  PtrListaODBC=^appoggio;
   Appoggio = record
     dsn : PChar;
     desc : PChar;
     next: PtrListaODBC;
  end;


var
  Form1: TForm1;

function GetListaDSN(MiaLista: PtrListaODBC): PChar; cdecl; external {$ifdef windows} 'ProgettoDLLODBC.dll'{$endif};

implementation

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
var
   app: PtrListaODBC;
   i: integer;
   valore: PChar;
begin
     app:=new (PtrListaODBC);
     GetListaDSN(app);
     i:=0;
     while (app<>nil) do
     begin
          valore:=app^.dsn;
          app:=app^.next;
     end;
end;

initialization
  {$I unit1.lrs}

end.     

theo:
In this case, it's not PChar.
h2pas translates:

ListaODBC = record
          dsn : array[0..255] of char;
          desc : array[0..255] of char;
          next : ^ListaODBC;
       end;
     PtrListaODBC = ListaODBC;

Use h2pas for header translation. Probaby it's stdcall instead of cdecl, I don't know.

captian jaster:
You can make pascal and C work together?

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