unit Unit1;

interface

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

type

  TMY = class(TThread)
  public                                                                              ThreadEnd:boolean;    
    constructor create(); overload;
    destructor Destroy(); overload;
    procedure execute; override;
  end;

  TForm1 = class(TForm)
    Button1: TButton;
    Panel1: TPanel;
    Button2: TButton;
    Panel2: TPanel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
    My: TMY;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

constructor TMY.create();
begin                                                                            
  ThreadEnd :=False;    
 FreeOnTerminate := True; 
inherited Create(False);
end;
destructor TMY.Destroy();
begin 
inherited Destroy;
end;
procedure TMY.execute;
var i: Integer;
begin 
for i := 1 to 5000 do 
 begin 
  Sleep(1); 
  Form1.Panel1.Caption := IntToStr(i); end;
  ThreadEnd :=True;    
end;
procedure TForm1.Button1Click(Sender: TObject);
begin 
  My := TMY.create;// 执行线程
end;
procedure TForm1.Button2Click(Sender: TObject);
var I:Cardinal; 
Isquit:Boolean;
begin Isquit:=GetExitCodeThread(My.handle,i) ;//检查线程是否结束 
if Isquit then Button2.Caption:='True' else Button2.Caption:='False';
 // My.ThreadEnd=True 也可以确定线程结束。
end;
end.