effektive Form.height?

[Kas Ob.]

Try these and pick your favorite one, or you can mix the result leaving little space for the resizing borders while having the exact size.

Delphi-Quellcode:

procedure TFormMain.Button1Click(Sender: TObject);
var
  Rect: TRect;
begin
  GetWindowRect(Self.Handle, Rect);
  FormBrowser.Width := Rect.Width;
  FormBrowser.Height := Rect.Height;
  FormBrowser.Left := self.Left + Rect.Width;
  FormBrowser.Top := Rect.Top;

  FormBrowser.Visible := True;
  WritePos;
end;

procedure TFormMain.Button2Click(Sender: TObject);
var
  Rect: TRect;
begin
  // need DwmApi in uses clause
  DwmGetWindowAttribute(Self.Handle, DWMWA_EXTENDED_FRAME_BOUNDS, @Rect, SizeOf(Rect));
  FormBrowser.Width := Rect.Width;
  FormBrowser.Height := Rect.Height;
  FormBrowser.Left := self.Left + Rect.Width;
  FormBrowser.Top := Rect.Top;

  FormBrowser.Visible := True;
  WritePos;
end;

https://learn.microsoft.com/en-us/wi...-getwindowrect
https://learn.microsoft.com/en-us/wi...indowattribute