添加线程安全结束代码的原因：1.如果对话框关闭时线程仍在运行，访问已释放内存程序崩溃！2. 资源泄漏风险如线程句柄未关闭、内存未释放、 GDI对象未释放、文件句柄未关闭，程序看似关闭，但进程仍在后台运行，再次启动程序可能失败。这里增加一个SafeTerminateThread()函数用于线程安全结束，在对话框析构函数、OnDestroy消息处理、及停止按钮中调用于线程安全函数。改进后完整代码如下。
SimpleThreadDemoDlg.h
// SimpleThreadDemoDlg.h : header file//#if!defined(AFX_SIMPLETHREADDEMODLG_H__1FDB3406_48D0_44E7_9CE2_1977BCCA5492__INCLUDED_)#defineAFX_SIMPLETHREADDEMODLG_H__1FDB3406_48D0_44E7_9CE2_1977BCCA5492__INCLUDED_#if_MSC_VER>1000#pragmaonce#endif// _MSC_VER > 1000/////////////////////////////////////////////////////////////////////////////// CSimpleThreadDemoDlg dialogclassCSimpleThreadDemoDlg:publicCDialog{// Constructionpublic:CSimpleThreadDemoDlg(CWnd*pParent=NULL);// standard constructorvirtual~CSimpleThreadDemoDlg();// 析构函数// 线程句柄HANDLE m_hThread;// 事件对象，用于线程同步HANDLE m_hStopEvent;// 线程控制标志// 线程控制BOOL m_bStopThread;// TRUE表示线程应该停止BOOL m_bThreadActive;// TRUE表示线程正在运行// 线程参数结构structTHREAD_PARAM{CSimpleThreadDemoDlg*pDlg;intnCounter;};private:// 添加安全终止方法voidSafeTerminateThread();// 静态线程函数staticUINTThreadProc(LPVOID pParam);// 线程工作函数voidDoThreadWork(intnIteration);// Dialog Data//{{AFX_DATA(CSimpleThreadDemoDlg)enum{IDD=IDD_SIMPLETHREADDEMO_DIALOG};// NOTE: the ClassWizard will add data members here//}}AFX_DATA// ClassWizard generated virtual function overrides//{{AFX_VIRTUAL(CSimpleThreadDemoDlg)protected:virtualvoidDoDataExchange(CDataExchange*pDX);// DDX/DDV support//}}AFX_VIRTUAL// Implementationprotected:HICON m_hIcon;// Generated message map functions//{{AFX_MSG(CSimpleThreadDemoDlg)virtualBOOLOnInitDialog();afx_msgvoidOnSysCommand(UINT nID,LPARAM lParam);afx_msgvoidOnPaint();afx_msg HCURSOROnQueryDragIcon();afx_msgvoidOnButtonStart();afx_msgvoidOnButtonStop();afx_msgvoidOnDestroy();//}}AFX_MSGDECLARE_MESSAGE_MAP()};//{{AFX_INSERT_LOCATION}}// Microsoft Visual C++ will insert additional declarations immediately before the previous line.#endif// !defined(AFX_SIMPLETHREADDEMODLG_H__1FDB3406_48D0_44E7_9CE2_1977BCCA5492__INCLUDED_)SimpleThreadDemoDlg.cpp
// SimpleThreadDemoDlg.cpp : implementation file//#include"stdafx.h"#include"SimpleThreadDemo.h"#include"SimpleThreadDemoDlg.h"#ifdef_DEBUG#definenewDEBUG_NEW#undefTHIS_FILEstaticcharTHIS_FILE[]=__FILE__;#endif// 线程参数结构体/////////////////////////////////////////////////////////////////////////////// CAboutDlg dialog used for App AboutclassCAboutDlg:publicCDialog{public:CAboutDlg();// Dialog Data//{{AFX_DATA(CAboutDlg)enum{IDD=IDD_ABOUTBOX};//}}AFX_DATA// ClassWizard generated virtual function overrides//{{AFX_VIRTUAL(CAboutDlg)protected:virtualvoidDoDataExchange(CDataExchange*pDX);// DDX/DDV support//}}AFX_VIRTUAL// Implementationprotected://{{AFX_MSG(CAboutDlg)//}}AFX_MSGDECLARE_MESSAGE_MAP()};CAboutDlg::CAboutDlg():CDialog(CAboutDlg::IDD){//{{AFX_DATA_INIT(CAboutDlg)//}}AFX_DATA_INIT}voidCAboutDlg::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_MAPEND_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////// CSimpleThreadDemoDlg dialogCSimpleThreadDemoDlg::CSimpleThreadDemoDlg(CWnd*pParent/*=NULL*/):CDialog(CSimpleThreadDemoDlg::IDD,pParent){//{{AFX_DATA_INIT(CSimpleThreadDemoDlg)m_bStopThread=FALSE;// 不要停止m_bThreadActive=FALSE;// 线程不在运行m_hThread=NULL;//}}AFX_DATA_INIT// Note that LoadIcon does not require a subsequent DestroyIcon in Win32m_hIcon=AfxGetApp()->LoadIcon(IDR_MAINFRAME);}voidCSimpleThreadDemoDlg::DoDataExchange(CDataExchange*pDX){CDialog::DoDataExchange(pDX);//{{AFX_DATA_MAP(CSimpleThreadDemoDlg)// NOTE: the ClassWizard will add DDX and DDV calls here//}}AFX_DATA_MAP}BEGIN_MESSAGE_MAP(CSimpleThreadDemoDlg,CDialog)//{{AFX_MSG_MAP(CSimpleThreadDemoDlg)ON_WM_SYSCOMMAND()ON_WM_PAINT()ON_WM_QUERYDRAGICON()ON_BN_CLICKED(IDC_BUTTON_START,OnButtonStart)ON_BN_CLICKED(IDC_BUTTON_STOP,OnButtonStop)ON_WM_DESTROY()//}}AFX_MSG_MAPEND_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////// CSimpleThreadDemoDlg message handlersBOOLCSimpleThreadDemoDlg::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 dialogSetIcon(m_hIcon,TRUE);// Set big iconSetIcon(m_hIcon,FALSE);// Set small icon// TODO: Add extra initialization herereturnTRUE;// return TRUE unless you set the focus to a control}voidCSimpleThreadDemoDlg::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.voidCSimpleThreadDemoDlg::OnPaint(){if(IsIconic()){CPaintDCdc(this);// device context for paintingSendMessage(WM_ICONERASEBKGND,(WPARAM)dc.GetSafeHdc(),0);// Center icon in client rectangleintcxIcon=GetSystemMetrics(SM_CXICON);intcyIcon=GetSystemMetrics(SM_CYICON);CRect rect;GetClientRect(&rect);intx=(rect.Width()-cxIcon+1)/2;inty=(rect.Height()-cyIcon+1)/2;// Draw the icondc.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.HCURSORCSimpleThreadDemoDlg::OnQueryDragIcon(){return(HCURSOR)m_hIcon;}// 线程函数UINTCSimpleThreadDemoDlg::ThreadProc(LPVOID pParam){THREAD_PARAM*pThreadParam=(THREAD_PARAM*)pParam;CSimpleThreadDemoDlg*pDlg=pThreadParam->pDlg;TRACE("线程开始运行\n");// 执行5次循环for(inti=1;i<=5;i++){// 检查停止标志if(pDlg->m_bStopThread){TRACE("线程接收到停止信号\n");break;}// 执行工作pDlg->DoThreadWork(i);// 休眠1秒Sleep(1000);}// 线程结束，更新状态pDlg->m_bThreadActive=FALSE;// 清理参数deletepThreadParam;TRACE("线程运行结束\n");return0;}voidCSimpleThreadDemoDlg::DoThreadWork(intnIteration){TRACE("执行第%d项工作\n",nIteration);// 这里可以添加实际的工作代码}/////////////////////////////////////////////////////////////////////////////// 启动线程voidCSimpleThreadDemoDlg::OnButtonStart(){TRACE("=== 启动线程 ===\n");TRACE("=== 启动线程 ===\n");if(m_bThreadActive){AfxMessageBox("线程已经在运行");return;}// 重置事件if(m_hStopEvent){ResetEvent(m_hStopEvent);}// 初始化标志m_bStopThread=FALSE;// 不要停止m_bThreadActive=TRUE;// 线程正在运行// 创建线程参数// 创建线程参数THREAD_PARAM*pParam=newTHREAD_PARAM;pParam->pDlg=this;pParam->nCounter=0;// 创建线程（使用CREATE_SUSPENDED，确保完全初始化后再运行）CWinThread*pThread=AfxBeginThread(ThreadProc,pParam,THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED);if(pThread==NULL){AfxMessageBox("创建线程失败");m_bThreadActive=FALSE;deletepParam;return;}// 保存句柄m_hThread=pThread->m_hThread;// 恢复线程运行pThread->ResumeThread();TRACE("线程启动成功，ID: %d\n",pThread->m_nThreadID);AfxMessageBox("线程已启动");}/////////////////////////////////////////////////////////////////////////////// 停止线程voidCSimpleThreadDemoDlg::OnButtonStop(){TRACE("=== 停止线程 ===\n");if(!m_bThreadActive){AfxMessageBox("没有正在运行的线程");return;}// 安全终止线程SafeTerminateThread();AfxMessageBox("线程已停止");}voidCSimpleThreadDemoDlg::SafeTerminateThread(){TRACE("安全终止线程\n");if(!m_bThreadActive){TRACE("线程未激活\n");return;}// 1. 设置停止标志和事件m_bStopThread=TRUE;if(m_hStopEvent){SetEvent(m_hStopEvent);}// 2. 等待线程正常结束if(m_hThread){TRACE("等待线程正常退出...\n");// 等待3秒让线程正常退出DWORD dwWaitResult=WaitForSingleObject(m_hThread,3000);if(dwWaitResult==WAIT_OBJECT_0){TRACE("线程正常退出\n");}elseif(dwWaitResult==WAIT_TIMEOUT){TRACE("线程超时未退出，尝试强制终止\n");// 3. 强制终止（最后手段）// 警告：这可能导致资源泄漏，只在必要时使用if(!TerminateThread(m_hThread,0)){TRACE("强制终止失败，错误代码: %d\n",GetLastError());}else{// 等待线程完全终止WaitForSingleObject(m_hThread,1000);TRACE("线程已被强制终止\n");}}// 4. 关闭句柄CloseHandle(m_hThread);m_hThread=NULL;}// 5. 重置状态m_bThreadActive=FALSE;m_bStopThread=FALSE;TRACE("安全终止线程完成\n");}voidCSimpleThreadDemoDlg::OnDestroy(){TRACE("=== 窗口销毁处理开始 ===\n");// 确保线程结束SafeTerminateThread();CDialog::OnDestroy();TRACE("=== 窗口销毁处理结束 ===\n");}CSimpleThreadDemoDlg::~CSimpleThreadDemoDlg(){// 确保线程结束if(m_bThreadActive&&m_hThread){// 设置停止事件SetEvent(m_hStopEvent);// 等待线程结束，最多等待5秒DWORD dwWait=WaitForSingleObject(m_hThread,5000);if(dwWait==WAIT_TIMEOUT){// 如果线程在5秒内没有结束，强制终止TerminateThread(m_hThread,0);TRACE("线程被强制终止\n");}// 关闭句柄CloseHandle(m_hThread);m_hThread=NULL;}// 关闭事件句柄if(m_hStopEvent){CloseHandle(m_hStopEvent);m_hStopEvent=NULL;}}Debug模式运行
