一个关于多线程的简单实例（抄书）

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    lblTime: TLabel;
    btnAdd: TButton;
    edt1: TEdit;
    edt2: TEdit;
    edt3: TEdit;
    lbl1: TLabel;
    lbl2: TLabel;
    procedure btnAddClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  timethread = class(TThread)
  protected
    procedure execute;override;
  end;
var
  Form1: TForm1;
  TIME_THREAD:timethread;

implementation

{$R *.dfm}

{ timethread }

procedure timethread.execute;
var
  go:Boolean;
  timestring:string;
begin
  go:=True;
  repeat
    timestring:=FormatDateTime('H:mm:ss am/pm',now);
    Form1.lblTime.Caption:=timestring;
  until go=False;
end;

procedure TForm1.btnAddClick(Sender: TObject);
begin
  edt3.Text:=IntToStr(StrToInt(edt1.Text)+strtoint(edt2.Text));
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  TIME_THREAD:=timethread.Create(false);
end;

end.