Can Delphi only use a .dll if required?

Question

I have added these two methods to the 1st unit of my Delphi 5 application.

function Inp(PortAddress: Integer): Integer; stdcall; external \'inpout32.dll\' na         


        

Answer 1

In Delphi versions prior to 2010, you have to use classic dynamic loading. Consider this typical (and simple) example calling the Beep function from Kernel32.dll (which you should not hardcode the path to in real code, of course!):

type
  TBeepFunc = function(dwFreq: DWORD; dwDuration: DWORD): BOOL; stdcall;

procedure TForm4.FormClick(Sender: TObject);
var
  lib: HMODULE;
  prc: TBeepFunc;
begin

  lib := LoadLibrary('C:\WINDOWS\System32\Kernel32.dll');
  if lib = 0 then RaiseLastOSError;
  try
    @prc := GetProcAddress(lib, 'Beep');
    if Assigned(prc) then
      prc(400, 2000)
    else
      ShowMessage('WTF? No Beep in Kernel32.dll?!');
  finally
    FreeLibrary(lib);
  end;
end;