Author: Jonas Bilinkevicius

How to hide and show the title bar of a TForm

Answer:

Here is how to hide the titlebar:

1   procedure TYourFormName.HideTitlebar;
2   var
3     Save: LongInt;
4   begin
5     if BorderStyle = bsNone then
6       Exit;
7     Save := GetWindowLong(Handle, GWL_STYLE);
8     if (Save and WS_CAPTION) = WS_CAPTION then
9     begin
10      case BorderStyle of
11        bsSingle, bsSizeable:
12          SetWindowLong(Handle, GWL_STYLE, Save and (not (WS_CAPTION)) or WS_BORDER);
13        bsDialog:
14          SetWindowLong(Handle, GWL_STYLE, Save and (not (WS_CAPTION)) or 
15  DS_MODALFRAME
16            or WS_DLGFRAME);
17      end;
18      Height := Height - GetSystemMetrics(SM_CYCAPTION);
19      Refresh;
20    end;
21  end;
22  
23  //And here is how we show it again:
24  
25  procedure TYourFormName.ShowTitlebar;
26  var
27    Save: LongInt;
28  begin
29    if BorderStyle = bsNone then
30      Exit;
31    Save := GetWindowLong(Handle, GWL_STYLE);
32    if (Save and WS_CAPTION) <> WS_CAPTION then
33    begin
34      case BorderStyle of
35        bsSingle, bsSizeable:
36          SetWindowLong(Handle, GWL_STYLE, Save or WS_CAPTION or WS_BORDER);
37        bsDialog:
38          SetWindowLong(Handle, GWL_STYLE, Save or WS_CAPTION or DS_MODALFRAME or
39            WS_DLGFRAME);
40      end;
41      Height := Height + GetSystemMetrics(SM_CYCAPTION);
42      Refresh;
43    end;
44  end;