unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  TInfoFunktion = function(about_what: pchar):pchar; stdcall;
  function info1(about_what: pchar):pchar;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
function info1(about_what: pchar):pchar;
var InfoFunktion: TInfoFunktion;
    Handle: THandle;
begin
  Handle:=LoadLibrary(PChar(ExtractFilePath(ParamStr(0))+'dll.dll'));
  if Handle <> 0 then begin
    @InfoFunktion := GetProcAddress(Handle, 'info');
    if @InfoFunktion <> nil then begin
      result := InfoFunktion(about_what);
    end;
    FreeLibrary(Handle);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var test:pchar;
begin
test:='test';
    showmessage(info1(@test));
end;

end.

library dll;



uses
  SysUtils,
  Classes;

{$R *.res}
function info(about_what: pchar):pchar; stdcall;
begin
  if about_what='test' then
  result := 'super1'
  else
  result:='super2';
end;

exports
  info;
begin
end.