type
  Tarray_of_tbutton = array of tbutton;
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    procedure MyArrayButtonsClick(Sender: TObject);
    procedure define_3x3_button_array;
  private
    { private declarations }
  public
    { public declarations }
  end;
var
  Form1: TForm1;
  my_array_of_tbutton : Tarray_of_tbutton;
procedure TForm1.define_3x3_button_array;
const
  max_horizontal = 3;
  max_vertical = 3;
var
  v_count, h_count, array_count : integer;
begin
  SetLength( my_array_of_tbutton, max_horizontal * max_vertical );
  for v_count := 0 to max_vertical - 1 do
   for h_count := 0 to max_horizontal - 1 do
     begin
       array_count := v_count * max_horizontal + h_count;
       my_array_of_tbutton[ array_count ] := new( tbutton(
my_array_of_tbutton ));
       my_array_of_tbutton[ array_count ].Parent := Self;
       my_array_of_tbutton[ array_count ].Left :=
         50 + h_count * 50;
       my_array_of_tbutton[ array_count ].Top :=
         50 + v_count * 50;
       my_array_of_tbutton[ array_count ].Tag :=
         array_count;
       my_array_of_tbutton[ array_count ].OnClick :=
         myArrayButtonsClick;
       my_array_of_tbutton[ array_count ].Caption :=
         inttostr( array_count );
     end;
end;

Full code is here: http://pastebin.com/ueKmjkrC

Options changed, recompiling clean with -B
Hint: Start of reading config file /etc/fpc.cfg
Hint: End of reading config file /etc/fpc.cfg
Free Pascal Compiler version 2.5.1 [2011/05/14] for i386 Copyright (c) 1993-2011 by Florian Klaempfl and others Target OS: Linux for i386
Compiling slide_puzzle.lpr
Compiling unit1.pas
unit1.pas(52,81) Error: Type identifier expected
unit1.pas(61,29) Error: Wrong number of parameters specified for call to "MyArrayButtonsClick"
unit1.pas(34,18) Hint: Found declaration: TForm1.MyArrayButtonsClick(TObject); unit1.pas(67,18) Error: overloaded functions have the same parameter list unit1.pas(34,18) Hint: Found declaration: TForm1.MyArrayButtonsClick(TObject); unit1.pas(67,18) Error: function header doesn't match any method of this class "TForm1.MyArrayButtonsClick(TObject);"
unit1.pas(34,18) Hint: Found declaration: TForm1.MyArrayButtonsClick(TObject); unit1.pas(79) Fatal: There were 4 errors compiling module, stopping

Best Regards,
Peter

my_array_of_tbutton[ array_count ] := TButton.Create(Self);

You forgot the address operator:
          @myArrayButtonsClick;

Mattias

Hi Mattias,

Mattias Gaertner wrote

On Sun, 22 May 2011 01:37:35 +1000 Peter Williams wrote:

[...]

Thanks for the help, Mattias. :-)