一个使用多媒体定时器的简单例子

　　1)新建一个工程，保存

2)添加一个Button和一个Label

3)修改unit1.h代码如下：

// ---------------------------------------------------------------------------

#ifndef Unit1H

#define Unit1H

// ---------------------------------------------------------------------------

#include

#include

#include

#include

// ---------------------------------------------------------------------------

class TForm1 : public TForm

{

__published: // IDE-managed Components

TButton *Button1;

TLabel *Label1;

void __fastcall Button1Click(TObject *Sender);

void __fastcall FormCloseQuery(TObject *Sender, bool &CanClose);

private: // User declarations

public: // User declarations

__fastcall TForm1(TComponent* Owner);

static void CALLBACK TimeProc(UINT uID,UINT uMsg,

DWord dwUser,DWORD dw1,DWORD dw2); // 定时器回调函数

int TimerID; // 定时器ID

};

// ---------------------------------------------------------------------------

extern PACKAGE TForm1 *Form1;

// ---------------------------------------------------------------------------

#endif

4)unit1.cpp代码如下：

// ---------------------------------------------------------------------------

#include

#include "mmsystem.h"

#pragma hdrstop

#include "Unit1.h"

// ---------------------------------------------------------------------------

#pragma package(smart_init)

#pragma resource "*.dfm"

TForm1 *Form1;

// ---------------------------------------------------------------------------

__fastcall TForm1::TForm1(TComponent* Owner)

: TForm(Owner)

{

TimerID = 0;

}

// ---------------------------------------------------------------------------

void CALLBACK TForm1::TimeProc(UINT uID,UINT uMsg, DWORD dwUser,DWORD dw1,DWORD dw2)

{

Form1->Label1->Caption = Now();

}

// ---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)

{

TimerID = timeSetEvent(1000, 0, (LPTIMECALLBACK)TimeProc, 0,

TIME_PERIODICTIME_CALLBACK_FUNCTION); // 设定多媒体定时器,1000ms

if(TimerID == 0) {

ShowMessage("创建失败");

}

}

// ---------------------------------------------------------------------------

void __fastcall TForm1::FormCloseQuery(TObject *Sender, bool &CanClose)

{

if(TimerID != 0) {

timeKillEvent(TimerID); // 释放定时器

}

}

// ---------------------------------------------------------------------------

运行效果：点击按钮后，Label1开始显示时间

测试环境：BCB5 + WIN98

作者信息：

"Mao Yanwei(citiz)"