library PreviewM;

{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }

uses
  SysUtils,
  Classes,
  Forms,
  Windows,
  Dialogs,
  MConnect,
  SConnect,
  MidasSpeedFix,
  UnitDMPrincipal in 'unitdmprincipal.pas' {DMPrincipal: TDataModule},
  UnitPreview in 'UnitPreview.pas' {FormPreview};

var
  SomeBuffer: Pointer;

procedure MyDLLProc(Reason: Integer);
begin
  if Reason = DLL_PROCESS_DETACH then
    begin
      { DLL é descarregada. Código de limpeza vai aqui. }
      while (Assigned(FormPreview)) or (FormPreview <> nil) do
        begin
          FreeAndNil(FormPreview);
        end;
      {      while (Assigned(DMPrincipal)) or (DMPrincipal <> nil) do
              begin
                FreeAndNil(DMPrincipal);
              end;}
      FreeMem(SomeBuffer);
    end;
end;

procedure ModalPreview(AForm: TDataModule; SocketC: TSocketConnection; NomeRel: PChar);
begin
  try
    DMPrincipal:=TDMPrincipal(AForm);
    if AForm.Owner.ClassName = 'TApplication' then
      begin
        Application.OnException:=TApplication(AForm.Owner).OnException;
      end;
    Application.CreateForm(TFormPreview, FormPreview);
    FormPreview.PreparaRel(NomeRel);
    FormPreview.ShowModal;
    FreeAndNil(FormPreview);
    //    FreeAndNil(DMPrincipal);
  except
    on E: Exception do
      begin
        MessageDlg(E.Message, mtError, [mbOK], 0);
        FreeAndNil(FormPreview);
      end;
  end;
end;
{ Mais código da DLL aqui que usa SomeBuffer. }
exports
  ModalPreview;
begin
  { Atribui nossso DLLProc à variável global DLLProc. }
  DLLProc:=@MyDLLProc;
  SomeBuffer:=AllocMem(1024);
end.