What is the best way to make a Delphi Application completely full screen?

Question

What is the best way to make a delphi application (delphi 2007 for win32 here) go completely full screen, removing the application border and covering windows task bar ?

Answer 1

In my case, the only working solution is:

procedure TFormHelper.FullScreenMode;
begin
  BorderStyle := bsNone;
  ShowWindowAsync(Handle, SW_MAXIMIZE);
end;

Answer 2

Well, this has always worked for me. Seems a bit simpler...

procedure TForm52.Button1Click(Sender: TObject);
begin
  BorderStyle := bsNone;
  WindowState := wsMaximized;
end;

Answer 3

How to constrain a sub-form within the Mainform like it was an MDI app., but without the headaches! (Note: The replies on this page helped me get this working, so that's why I posted my solution here)

private
{ Private declarations }
  StickyAt: Word;
  procedure WMWINDOWPOSCHANGING(Var Msg: TWMWINDOWPOSCHANGING); Message M_WINDOWPOSCHANGING;
  Procedure WMGetMinMaxInfo(Var msg: TWMGetMinMaxInfo); message WM_GETMINMAXINFO;

later...

    procedure TForm2.WMWINDOWPOSCHANGING(var Msg: TWMWINDOWPOSCHANGING);
    var
      A, B: Integer;
      iFrameSize: Integer;
      iCaptionHeight: Integer;
      iMenuHeight: Integer;
    begin

      iFrameSize := GetSystemMetrics(SM_CYFIXEDFRAME);
      iCaptionHeight := GetSystemMetrics(SM_CYCAPTION);
      iMenuHeight := GetSystemMetrics(SM_CYMENU);

      // inside the Mainform client area
      A := Application.MainForm.Left + iFrameSize;
      B := Application.MainForm.Top + iFrameSize + iCaptionHeight + iMenuHeight;

      with Msg.WindowPos^ do
      begin

        if x <= A + StickyAt then
          x := A;

        if x + cx >= A + Application.MainForm.ClientWidth - StickyAt then
          x := (A + Application.MainForm.ClientWidth) - cx + 1;

       if y <= B + StickyAt then
         y := B;

       if y + cy >= B + Application.MainForm.ClientHeight - StickyAt then
         y := (B + Application.MainForm.ClientHeight) - cy + 1;

      end;
end;

and yet more...

Procedure TForm2.WMGetMinMaxInfo(Var msg: TWMGetMinMaxInfo);
var
  iFrameSize: Integer;
  iCaptionHeight: Integer;
  iMenuHeight: Integer;
Begin
  inherited;
  iFrameSize := GetSystemMetrics(SM_CYFIXEDFRAME);
  iCaptionHeight := GetSystemMetrics(SM_CYCAPTION);
  iMenuHeight := GetSystemMetrics(SM_CYMENU);
  With msg.MinMaxInfo^.ptMaxPosition Do
  begin
    // position of top when maximised
    X := Application.MainForm.Left + iFrameSize + 1;
    Y := Application.MainForm.Top + iFrameSize + iCaptionHeight + iMenuHeight + 1;
  end;
  With msg.MinMaxInfo^.ptMaxSize Do
  Begin
     // width and height when maximized
     X := Application.MainForm.ClientWidth;
     Y := Application.MainForm.ClientHeight;
  End;
  With msg.MinMaxInfo^.ptMaxTrackSize Do
  Begin
     // maximum size when maximised
     X := Application.MainForm.ClientWidth;
     Y := Application.MainForm.ClientHeight;
  End;
  // to do: minimum size (maybe)
End;