unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 ExtCtrls, StdCtrls, mmsystem;
type
 TForm1 = class(TForm)
  Edit1: TEdit;
  Edit2: TEdit;
  Edit3: TEdit;
  Button1: TButton;
  Button2: TButton;
  Timer1: TTimer;
  Label1: TLabel;
  Label2: TLabel;
  Label3: TLabel;
  procedure FormCreate(Sender: TObject);
  procedure Button1Click(Sender: TObject);
  procedure Timer1Timer(Sender: TObject);
  procedure Button2Click(Sender: TObject);
 private
  { Private declarations }
 public
  { Public declarations }
 end;
var
 Form1: TForm1;
 acttime1,acttime2:cardinal;
 smmcount,stimercount,spcount:single;
 htimeid:integer;
 iten:integer;
 protimecallback:tfntimecallback;
 procedure timeproc(utimerid, umessage: uint; dwuser, dw1, dw2: dword) stdcall;
 procedure proendcount;
implementation
{$R *.DFM}
//timesetevent的回調函數
procedure proendcount;
begin
 acttime2:=gettickcount-acttime1;
 form1.button2.enabled :=false;
 form1.button1.enabled :=true;
 form1.timer1.enabled :=false;
 smmcount:=60;
 stimercount:=60;
 spcount:=-1;
 timekillevent(htimeid);
end;
procedure timeproc(utimerid, umessage: uint; dwuser, dw1, dw2: dword) stdcall;
begin
 form1.edit2.text:=floattostr(smmcount);
 smmcount:=smmcount-0.01;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
 button1.caption :='開始倒計時';
 button2.caption :='結束倒計時';
 button2.enabled :=false;
 button1.enabled :=true;
 timer1.enabled :=false;
 smmcount:=60;
 stimercount:=60;
 spcount:=60;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
 lgtick1,lgtick2,lgper:tlargeinteger;
 ftemp:single;
begin
 button2.enabled :=true;
 button1.enabled :=false;
 timer1.enabled :=true;
 timer1.interval :=10;
 protimecallback:=timeproc;
 htimeid:=timesetevent(10,0,protimecallback,1,1);
 acttime1:=gettickcount;
 //獲得系統(tǒng)的高性能頻率計數器在一毫秒內的震動次數
 queryperformancefrequency(lgper);
 ftemp:=lgper/1000;
 iten:=trunc(ftemp*10);
 queryperformancecounter(lgtick1);
 lgtick2:=lgtick1;
 spcount:=60;
 while spcount>0 do
 begin
  queryperformancecounter(lgtick2);
  //如果時鐘震動次數超過10毫秒的次數則刷新edit3的顯示
  if lgtick2 - lgtick1 > iten then
  begin
   lgtick1 := lgtick2;
   spcount := spcount - 0.01;
   edit3.text := floattostr(spcount);
   application.processmessages;
  end;
 end;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
begin
 edit1.text := floattostr(stimercount);
 stimercount:=stimercount-0.01;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
 proendcount;
 //顯示從開始記數到記數實際經過的時間
 showmessage('實際經過時間'+inttostr(acttime2)+'毫秒');
end;
end.