timesetevent与timekillevent的用法

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的回调函数
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 :='开始倒计时';
  button2.caption :='结束倒计时';
  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;

//获得系统的高性能频率计数器在一毫秒内的震动次数
  queryperformancefrequency(lgper);
  ftemp:=lgper/1000;
  iten:=trunc(ftemp*10);
  queryperformancecounter(lgtick1);
  lgtick2:=lgtick1;
  spcount:=60;

while spcount>0 do
  begin
    queryperformancecounter(lgtick2);

//如果时钟震动次数超过10毫秒的次数则刷新edit3的显示
    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;

//显示从开始记数到记数实际经过的时间
  showmessage('实际经过时间'+inttostr(acttime2)+'毫秒');
end;

end.

http://blog.csdn.net/diligentcatrich/article/details/7008271