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

Try:

Align = alClient    
FormStyle = fsStayOnTop

This always align to the primary monitor;

Answer 2

Put to the form onShow event such code:

  WindowState:=wsMaximized;

And to the OnCanResize this:

  if (newwidth<width) and (newheight<height) then
    Resize:=false;

Answer 3

You need to make sure Form position is poDefaultPosOnly.

Form1.Position := poDefaultPosOnly;
Form1.FormStyle := fsStayOnTop;
Form1.BorderStyle := bsNone;
Form1.Left := 0;
Form1.Top := 0;
Form1.Width := Screen.Width;
Form1.Height := Screen.Height;

Tested and works on Win7 x64.

Answer 4

A Google search turned up the following, additional methods:

(though I think I'd try Roddy's method first)

Manually fill the screen (from: About Delphi)

procedure TSomeForm.FormShow(Sender: TObject) ;
var
   r : TRect;
begin
   Borderstyle := bsNone;
   SystemParametersInfo
      (SPI_GETWORKAREA, 0, @r,0) ;
   SetBounds
     (r.Left, r.Top, r.Right-r.Left, r.Bottom-r.Top) ;
end;

Variation on a theme by Roddy

FormStyle := fsStayOnTop;
BorderStyle := bsNone;
Left := 0;
Top := 0;
Width := Screen.Width;
Height := Screen.Height;

The WinAPI way (by Peter Below from TeamB)

private  // in form declaration
    Procedure WMGetMinMaxInfo(Var msg: TWMGetMinMaxInfo);
      message WM_GETMINMAXINFO;

Procedure TForm1.WMGetMinMaxInfo(Var msg: TWMGetMinMaxInfo);
  Begin
    inherited;
    With msg.MinMaxInfo^.ptMaxTrackSize Do Begin
      X := GetDeviceCaps( Canvas.handle, HORZRES ) + (Width - ClientWidth);
      Y := GetDeviceCaps( Canvas.handle, VERTRES ) + (Height - ClientHeight
);
    End;
  End;

procedure TForm1.Button2Click(Sender: TObject);
Const
  Rect: TRect = (Left:0; Top:0; Right:0; Bottom:0);
  FullScreen: Boolean = False;
begin
  FullScreen := not FullScreen;  
  If FullScreen Then Begin
    Rect := BoundsRect;
    SetBounds(
      Left - ClientOrigin.X,
      Top - ClientOrigin.Y,
      GetDeviceCaps( Canvas.handle, HORZRES ) + (Width - ClientWidth),
      GetDeviceCaps( Canvas.handle, VERTRES ) + (Height - ClientHeight ));
  //  Label2.caption := IntToStr(GetDeviceCaps( Canvas.handle, VERTRES ));
  End
  Else
    BoundsRect := Rect;
end; 

Answer 5

Hm. Looking at the responses I seem to remember dealing with this about 8 years ago when I coded a game. To make debugging easier, I used the device-context of a normal, Delphi form as the source for a fullscreen display.

The point being, that DirectX is capable of running any device context fullscreen - including the one allocated by your form.

So to give an app "true" fullscreen capabilities, track down a DirectX library for Delphi and it will probably contain what you need out of the box.

Answer 6

Maximize the form and hide the title bar. The maximize line is done from memory, but I'm pretty sure WindowState is the property you want.

There's also this article, but that seems too complicated to me.

procedure TForm1.FormCreate(Sender: TObject) ;
begin
   //maximize the window
   WindowState := wsMaximized;
   //hide the title bar
   SetWindowLong(Handle,GWL_STYLE,GetWindowLong(Handle,GWL_STYLE) and not WS_CAPTION);
   ClientHeight := Height;
end;

Edit: Here's a complete example, with "full screen" and "restore" options. I've broken out the different parts into little procedures for maximum clarity, so this could be greatly compressed into just a few lines.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    btnGoFullScreen: TButton;
    btnNotFullScreen: TButton;
    btnShowTitleBar: TButton;
    btnHideTitleBar: TButton;
    btnQuit: TButton;
    procedure btnGoFullScreenClick(Sender: TObject);
    procedure btnShowTitleBarClick(Sender: TObject);
    procedure btnHideTitleBarClick(Sender: TObject);
    procedure btnNotFullScreenClick(Sender: TObject);
    procedure btnQuitClick(Sender: TObject);
  private
    SavedLeft : integer;
    SavedTop : integer;
    SavedWidth : integer;
    SavedHeight : integer;
    SavedWindowState : TWindowState;
    procedure FullScreen;
    procedure NotFullScreen;
    procedure SavePosition;
    procedure HideTitleBar;
    procedure ShowTitleBar;
    procedure RestorePosition;
    procedure MaximizeWindow;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btnQuitClick(Sender: TObject);
begin
  Application.Terminate;
end;

procedure TForm1.btnGoFullScreenClick(Sender: TObject);
begin
  FullScreen;
end;

procedure TForm1.btnNotFullScreenClick(Sender: TObject);
begin
  NotFullScreen;
end;

procedure TForm1.btnShowTitleBarClick(Sender: TObject);
begin
  ShowTitleBar;
end;

procedure TForm1.btnHideTitleBarClick(Sender: TObject);
begin
  HideTitleBar;
end;

procedure TForm1.FullScreen;
begin
  SavePosition;
  HideTitleBar;
  MaximizeWindow;
end;

procedure TForm1.HideTitleBar;
begin
  SetWindowLong(Handle,GWL_STYLE,GetWindowLong(Handle,GWL_STYLE) and not WS_CAPTION);
  ClientHeight := Height;
end;

procedure TForm1.MaximizeWindow;
begin
  WindowState := wsMaximized;
end;

procedure TForm1.NotFullScreen;
begin
  RestorePosition;
  ShowTitleBar;
end;

procedure TForm1.RestorePosition;
begin
  //this proc uses what we saved in "SavePosition"
  WindowState := SavedWindowState;
  Top := SavedTop;
  Left := SavedLeft;
  Width := SavedWidth;
  Height := SavedHeight;
end;

procedure TForm1.SavePosition;
begin
  SavedLeft := Left;
  SavedHeight := Height;
  SavedTop := Top;
  SavedWidth := Width;
  SavedWindowState := WindowState;
end;

procedure TForm1.ShowTitleBar;
begin
  SetWindowLong(Handle,gwl_Style,GetWindowLong(Handle,gwl_Style) or ws_Caption or ws_border);
  Height := Height + GetSystemMetrics(SM_CYCAPTION);
  Refresh;
end;

end.