Resize a Form vertically only?

[Ian Branch 127]

Hi Team,

Can I allow a Form to resize vertically only, not horizontally at all?

If so, how please?

Regards & TIA,

Ian

[haentschman 92]

Hi...

 

TForm.Contraints are your friends. http://docwiki.embarcadero.com/Libraries/Seattle/en/Vcl.Controls.TControl.Constraints

Edited July 7, 2020 by haentschman

[Ian Branch 127]

Ah Ha!  Tks haentschman.  I have never used constraints.  I shall have a play.

[Uwe Raabe 2057]

There is also an OnConstrainedResize event.

[David Heffernan 2345]

In addition to constraining the window's size, you should consider giving the user visual feedback for their attempts to resize.

 

Do this by handling the WM_NCHITTEST message: https://docs.microsoft.com/en-gb/windows/win32/inputdev/wm-nchittest

 

type
  TForm1 = class(TForm)
  protected
    procedure WMNCHitTest(var Message: TWMNCHitTest); message WM_NCHITTEST;
  end;

....

procedure TForm1.WMNCHitTest(var Message: TWMNCHitTest);
begin
  inherited;
  case Message.Result of
  HTLEFT,HTRIGHT:
    Message.Result := HTCAPTION;
  HTTOPLEFT,HTTOPRIGHT:
    Message.Result := HTTOP;
  HTBOTTOMLEFT,HTBOTTOMRIGHT:
    Message.Result := HTBOTTOM;
  end;
end;