(*----下面這個程序介紹了我們在使用線程及未使用線程二種情況下，運行該程序的反
應(yīng)。當(dāng)點UsedThread按鈕時，則建立一個線程，這時我們可以在程序進(jìn)行計算的同
時，改變窗體的尺寸及移動它。當(dāng)按下NoUsedThread按鈕時，不建立線程，我們會發(fā)
現(xiàn)在程序沒有計算完之前根本不能做其它任何事情！

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    UsedThread: TBitBtn;
    NoUsedThread: TBitBtn;
    PRocedure UsedThreadClick(Sender: TObject);
    procedure NoUsedThreadClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function MyThreadFunc(P:pointer):Longint;stdcall;
var
  i:longint;
  DC:HDC;
  S:string;
begin
  DC:=GetDC(Form1.Handle);
  for i:=0 to 500000 do begin
    S:=Inttostr(i);
    Textout(DC,10,10,Pchar(S),length(S));
  end;
  ReleaseDC(Form1.Handle,DC);
end;

procedure TForm1.UsedThreadClick(Sender: TObject);
var
  hThread:Thandle;//定義一個句柄
  ThreadID:DWord;
begin
//創(chuàng)建線程，同時線程函數(shù)被調(diào)用
  hthread:=CreateThread(nil,0,@MyThreadfunc,nil,0,ThreadID);
  if hThread=0 then
  messagebox(Handle,'Didn’tCreateaThread',nil,MB_OK);
end;

procedure TForm1.NoUsedThreadClick(Sender: TObject);
begin
  MyThreadfunc(nil);
  //沒有創(chuàng)建線程時，直接調(diào)用線程函數(shù)
end;
end.