MFC高精度计时器实现方案

程序功能：实现精度为0.01秒的计时器。在编辑框中IDC_EDIT_INPUT 输入时间，按启动按钮OnButtonStart时启动线程计时，在计时过程中实时更新静态文本控件IDC_STATIC_DISPLAY 中时间，按停止按钮OnButtonStop时静态文本控件IDC_STATIC_DISPLAY 中显示当前计时时间，当计时到达输入时间时，停止线程，同时记录下最终的时间），并重置计时器的运行状态。该程序用到计时器类CElapsed它是一个计算时间间隔的工具。

CElapsed.h相关代码

cpp 复制代码

// CElapsed.h: 高精度计时器类
//

#ifndef __CELAPSED_H__
#define __CELAPSED_H__

class CElapsed
{
public:
    CElapsed();
    ~CElapsed();

    void Start();        // 开始计时
    double Now();        // 获取经过的时间(毫秒)
    double NowSec();     // 获取经过的时间(秒)

private:
    LARGE_INTEGER m_liFreq;      // 计时器频率
    LARGE_INTEGER m_liStart;     // 开始计时的时间点
    bool m_bHighResTimer;        // 是否支持高精度计时器
};

#endif // __CELAPSED_H__

CElapsed.cpp相关代码

cpp 复制代码

// CElapsed.cpp: 高精度计时器类实现
//

#include "stdafx.h"
#include "CElapsed.h"

CElapsed::CElapsed()
{
    // 检测是否支持高精度计时器
    m_bHighResTimer = (QueryPerformanceFrequency(&m_liFreq) != 0);
    m_liStart.QuadPart = 0;
}

CElapsed::~CElapsed()
{
}

// 开始计时
void CElapsed::Start()
{
    if (m_bHighResTimer)
    {
        QueryPerformanceCounter(&m_liStart);
    }
    else
    {
        m_liStart.LowPart = GetTickCount();
        m_liStart.HighPart = 0;
    }
}

// 获取经过的时间(毫秒)
double CElapsed::Now()
{
    if (m_bHighResTimer)
    {
        LARGE_INTEGER liNow;
        QueryPerformanceCounter(&liNow);
        return ((liNow.QuadPart - m_liStart.QuadPart) * 1000.0) / m_liFreq.QuadPart;
    }
    else
    {
        return (double)(GetTickCount() - m_liStart.LowPart);
    }
}

// 获取经过的时间(秒)
double CElapsed::NowSec()
{
    return Now() / 1000.0;
}

MyTimerDlg.h相关代码

cpp 复制代码

// MyTimerDlg.h : header file
//
#define ID_UPDATE_DISPLAY 1001
#if !defined(AFX_MYTIMERDLG_H__055F2DFB_689D_409A_8AEB_BB38B7D1D42F__INCLUDED_)
#define AFX_MYTIMERDLG_H__055F2DFB_689D_409A_8AEB_BB38B7D1D42F__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "CElapsed.h"
/////////////////////////////////////////////////////////////////////////////
// CMyTimerDlg dialog

class CMyTimerDlg : public CDialog
{
// Construction
public:
	CMyTimerDlg(CWnd* pParent = NULL);	// standard constructor

// Dialog Data
	//{{AFX_DATA(CMyTimerDlg)
	enum { IDD = IDD_MYTIMER_DIALOG };
		// NOTE: the ClassWizard will add data members here
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CMyTimerDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);	// DDX/DDV support
	//}}AFX_VIRTUAL
void UpdateDisplay(double dRemainingTime);
    void StopTimer();     // 停止计时器的内部函数

    CElapsed m_elapsedTimer;  // 高精度计时器
    double m_dInputTime;      // 输入的总时间(秒)
    double m_dElapsedTime;    // 已过去的时间(秒)
    bool m_bRunning;          // 计时器是否在运行
    bool m_bThreadRunning;    // 更新线程是否在运行
    static UINT TimerThreadProc(LPVOID pParam); // 计时器线程函数
    CWinThread* m_pTimerThread; // 计时器线程指针
// Implementation
protected:
	HICON m_hIcon;
 private:
    double m_dFinalTime;       // 记录停止时的最终时间
    bool m_bCompleted;         // 标记计时是否已完成   
	// Generated message map functions
	//{{AFX_MSG(CMyTimerDlg)
	virtual BOOL OnInitDialog();
	afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
	afx_msg void OnPaint();
	afx_msg HCURSOR OnQueryDragIcon();
	afx_msg void OnButtonStart();
	afx_msg void OnButtonStop();
	afx_msg LRESULT OnUpdateDisplay(WPARAM wParam, LPARAM lParam);
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
		enum { WM_UPDATE_DISPLAY = WM_USER + 100 };
};

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_MYTIMERDLG_H__055F2DFB_689D_409A_8AEB_BB38B7D1D42F__INCLUDED_)

MyTimerDlg.cpp相关代码

cpp 复制代码

// MyTimerDlg.cpp : implementation file
//

#include "stdafx.h"
#include "MyTimer.h"
#include "MyTimerDlg.h"
#include <math.h>
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyTimerDlg dialog

CMyTimerDlg::CMyTimerDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CMyTimerDlg::IDD, pParent)
{

	//{{AFX_DATA_INIT(CMyTimerDlg)
	m_bRunning = false;
    m_bThreadRunning = false;
    m_pTimerThread = NULL;
    m_dInputTime = 0.0;
    m_dElapsedTime = 0.0;
    m_dFinalTime = 0.0;        // 初始化最终时间
    m_bCompleted = false;      // 初始化完成状态
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMyTimerDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CMyTimerDlg)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMyTimerDlg, CDialog)
	//{{AFX_MSG_MAP(CMyTimerDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_START, OnButtonStart)
	ON_BN_CLICKED(IDC_BUTTON_STOP, OnButtonStop)
	ON_MESSAGE(WM_UPDATE_DISPLAY, OnUpdateDisplay)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyTimerDlg message handlers

BOOL CMyTimerDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	SetDlgItemText(IDC_STATIC_DISPLAY, _T("0.0"));
    SetDlgItemText(IDC_EDIT_INPUT, _T("10.0")); // 默认10秒
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CMyTimerDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMyTimerDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMyTimerDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CMyTimerDlg::OnButtonStart() 
{
if (m_bRunning) return;
     // 重置状态
    m_bCompleted = false;
    m_dFinalTime = 0.0;
    // 获取编辑框中输入的时间(秒)
    CString strTime;
    GetDlgItemText(IDC_EDIT_INPUT, strTime);
    m_dInputTime = atof(strTime);
    
    if (m_dInputTime <= 0.0)
    {
        MessageBox(_T("请输入有效的时间(大于0)"), _T("错误"), MB_ICONERROR);
        return;
    }
    
    // 重置计时器
    m_elapsedTimer.Start();
    m_bRunning = true;
    m_bThreadRunning = true;
    
    // 启动前先更新一次显示
   // UpdateDisplay(m_dInputTime);
UpdateDisplay(0.0);
    // 启动计时器线程
 //   m_bThreadRunning = true;
    m_pTimerThread = AfxBeginThread(TimerThreadProc, this, THREAD_PRIORITY_NORMAL);
	
}

void CMyTimerDlg::OnButtonStop() 
{
 if (!m_bRunning) return;
  if (m_bCompleted)
    {
        UpdateDisplay(m_dFinalTime);
        return;
    }
    
    // 先获取当前时间值
   
   // dCurrentTime = min(dCurrentTime, m_dInputTime); // 不超过输入值
    
    // 停止计时器
    StopTimer();
   double dCurrentTime = m_elapsedTimer.NowSec();  
    // 显示停止时的当前值
    UpdateDisplay(dCurrentTime);
}


void CMyTimerDlg::StopTimer()
{
    if (!m_bRunning) return;
    
    m_bThreadRunning = false;
    m_bRunning = false;
    
    if (m_pTimerThread)
    {
        WaitForSingleObject(m_pTimerThread->m_hThread, 1000);
        m_pTimerThread = NULL;
    }
}



LRESULT CMyTimerDlg::OnUpdateDisplay(WPARAM wParam, LPARAM lParam)
{
    double dRemainingTime = *(double*)wParam;
    UpdateDisplay(dRemainingTime);
    return 0;
}

//void CMyTimerDlg::UpdateDisplay(double dRemainingTime)
void CMyTimerDlg::UpdateDisplay(double dElapsedTime)
{
    CString strTime;
//	  double dDisplayTime = min(dElapsedTime, m_dInputTime);
    strTime.Format(_T("%.2f"),dElapsedTime); // 保持0.01秒精度
    SetDlgItemText(IDC_STATIC_DISPLAY, strTime);
}


UINT CMyTimerDlg::TimerThreadProc(LPVOID pParam)
{
    CMyTimerDlg* pDlg = (CMyTimerDlg*)pParam;
    const double UPDATE_INTERVAL = 0.01; // 0.01秒更新间隔
    
    CElapsed updateTimer;
    updateTimer.Start();
    
    while (pDlg->m_bThreadRunning)
    {
        double dElapsedTime = pDlg->m_elapsedTimer.NowSec();
        
        // 发送当前经过的时间值
        double* pCurrentTime = new double(dElapsedTime);
        pDlg->PostMessage(WM_UPDATE_DISPLAY, (WPARAM)pCurrentTime, 0);
        
        // 如果达到输入时间，自动停止
        if (dElapsedTime >= pDlg->m_dInputTime)
        {
            pDlg->m_bCompleted = true;      // 标记计时完成
            pDlg->m_dFinalTime = pDlg->m_dInputTime; // 记录最终时间
            pDlg->m_bThreadRunning = false;
            
            // 发送最后一次更新，确保显示正确的时间
            double* pFinalTime = new double(pDlg->m_dFinalTime);
            pDlg->PostMessage(WM_UPDATE_DISPLAY, (WPARAM)pFinalTime, 0);
            break;
        }
        
        // 精确等待
        double dWaitTime = UPDATE_INTERVAL - fmod(updateTimer.NowSec(), UPDATE_INTERVAL);
        if (dWaitTime > 0)
        {
            Sleep(static_cast<DWORD>(dWaitTime * 1000));
        }
    }
     pDlg->StopTimer();
    return 0;
}

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