Избавление от скроллов в MDI-форме

{ Избавление от ScrollBar'ов в MDI-форме. (С) Peter Below (TeamB)              }
{ Не надо VCL переписывать :-)                                                 }
 
unit MainForm;
 
interface
 
uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Menus;
 
type
  TfMain = class(TForm)
    MainMenu1: TMainMenu;
    Newchild1: TMenuItem;
    Newchild2: TMenuItem;
    procedure Newchild2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  fMain: TfMain;
 
implementation
 
uses ChildForm;
 
{$R *.DFM}
 
procedure TfMain.Newchild2Click(Sender: TObject);
begin
  with TfChild.Create(Application) do
    Show();
end;
 
function ClientWindowProc( wnd: HWND; msg: Cardinal; wparam, lparam: Integer ): Integer; stdcall;
var
  f: Pointer;
begin
  f := Pointer( GetWindowLong( wnd, GWL_USERDATA ));
  case msg of
  WM_NCCALCSIZE:
    if ( GetWindowLong( wnd, GWL_STYLE ) and
                       (WS_HSCROLL or WS_VSCROLL)) <> 0 then
      SetWindowLong( wnd, GWL_STYLE, GetWindowLong( wnd, GWL_STYLE )
                                   and not (WS_HSCROLL or WS_VSCROLL));
  end;
  Result := CallWindowProc( f, wnd, msg, wparam, lparam );
end;
 
procedure TfMain.FormCreate(Sender: TObject);
begin
  if ClientHandle <> 0 then begin
    if GetWindowLong( ClientHandle, GWL_USERDATA ) <> 0 then
      Exit;  {cannot subclass client window, userdata already in use}
    SetWindowLong(ClientHandle, GWL_USERDATA, SetWindowLong( ClientHandle,
                                GWL_WNDPROC, integer( @ClientWindowProc)));
end;
 
end;
 
end.

Взято из https://forum.sources.ru