Código Delphi [-]
procedure TThread1.Execute;
var
begin
...
form1.button4.enabled:= true;
...
end;

Código Delphi [-]
procedure TThread1.Execute;
var
begin
...
form1.button4.enabled:= true;
...
end;

Código Delphi [-]
  // Incrementar un progressbar del formulario
  pb.Position := (pb.Position + FStep) MOD 100;

Código Delphi [-]
  // Cambiar el color de un panel del formulario
  FColor := RGB(Random(255), Random(255), Random(255));
  pnb.Color := FColor;

Código Delphi [-]
procedure TPanelColorThread.ChangeColor;
begin
  FColor := RGB(Random(255), Random(255), Random(255));
  pnb.Color := FColor;
end;

...

  // La llamada
  while true do begin
    Synchronize(ChangeColor);
  end;

Código Delphi [-]
procedure TThread1.Execute;
var
begin
  ...
  form1.button4.enabled:= true;
  ...
end;

Código Delphi [-]
...

procedure TThread1.UpdateEdit();
var
begin
  ...
  form1.button4.enabled:= true;
  ...
end;


procedure TThread1.Execute;
var
begin
  ...
  Synchronize(UpdateEdit);
  ...
end;

Código Delphi [-]
unit unit2;

interface

uses SysUtils, Classes;

type
  Thilo = class(tThread)
  private
    procedure updatEdit;

  protected
    procedure Execute; override;
  end;

implementation

uses unit1;

//Thilo

procedure tHilo.execute;
begin
  synchronize(updatEdit);
end;

procedure tHilo.updatEdit;
var
  i: integer;

begin
  form1.progressBar1.max:= 1000000;
  for i:= 0 to form1.progressBar1.max -1 do
    form1.progressBar1.position:= i;
end;
end.

Código Delphi [-]
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ProgressBar1: TProgressBar;
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
uses unit2;

var
    FMiHilo: THilo;
{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  FMiHilo := THilo.Create(false);
end;

end.

Código Delphi [-]
//Thilo
procedure tHilo.execute;
var
  i:integer;
begin

  // para inicializar el Max
  synchronize(updatEdit);

  for i := 0 to form1.progressBar1.max -1 do begin
    cont := i;
    synchronize(updatEdit);
 
    // para que te de tiempo a hacer algo....
    sleep(10);
  end;
end;

procedure tHilo.updatEdit;
begin
  form1.progressBar1.max:= 1000;
  form1.progressBar1.position:= cont;
end;

Código Delphi [-]
Procedure TPrincipal.Button1Click(Sender: TObject);
begin
  TrocearArchivo(labEdit1.Text,2048);
  button2.Enabled:= true;
end;