??xml version="1.0" encoding="utf-8" standalone="yes"?>久久99国产精品99久久,国产精品久久久久jk制服,办公室久久精品http://www.shnenglu.com/swo2006/category/3204.htmlzh-cnFri, 23 May 2008 16:05:19 GMTFri, 23 May 2008 16:05:19 GMT60深入出Win32多线E设计之MFC的多U程[转]http://www.shnenglu.com/swo2006/articles/11378.htmlswoswoThu, 17 Aug 2006 14:30:00 GMThttp://www.shnenglu.com/swo2006/articles/11378.htmlhttp://www.shnenglu.com/swo2006/comments/11378.htmlhttp://www.shnenglu.com/swo2006/articles/11378.html#Feedback0http://www.shnenglu.com/swo2006/comments/commentRss/11378.htmlhttp://www.shnenglu.com/swo2006/services/trackbacks/11378.html 深入出Win32多线E设计之MFC的多U程(ZT)
1、创建和l止U程

  在MFCE序中创Z个线E,宜调用AfxBeginThread函数。该函数因参C同而具有两U重载版本,分别对应工作者线E和用户接口QUIQ线E?br />
  工作者线E?br />
CWinThread *AfxBeginThread(
 AFX_THREADPROC pfnThreadProc, //控制函数
 LPVOID pParam, //传递给控制函数的参?br /> int nPriority = THREAD_PRIORITY_NORMAL, //U程的优先
 UINT nStackSize = 0, //U程的堆栈大?br /> DWORD dwCreateFlags = 0, //U程的创建标?br /> LPSECURITY_ATTRIBUTES lpSecurityAttrs = NULL //U程的安全属?br />);

  工作者线E编E较为简单,只需~写U程控制函数和启动线E即可。下面的代码l出了定义一个控制函数和启动它的q程Q?br />
//U程控制函数
UINT MfcThreadProc(LPVOID lpParam)
{
 CExampleClass *lpObject = (CExampleClass*)lpParam;
 if (lpObject == NULL || !lpObject->IsKindof(RUNTIME_CLASS(CExampleClass)))
  return - 1; //输入参数非法
 //U程成功启动
 while (1)
 {
  ...//
 }
 return 0;
}

//在MFCE序中启动线E?br />AfxBeginThread(MfcThreadProc, lpObject);

  UIU程

  创徏用户界面U程Ӟ必须首先从CWinThread zc,q?DECLARE_DYNCREATE ?IMPLEMENT_DYNCREATE 宏声明此cR?br />
  下面l出了CWinThreadcȝ原型Q添加了关于光要函数功能和是否需要被l承c重载的注释Q:

class CWinThread : public CCmdTarget
{
 DECLARE_DYNAMIC(CWinThread)

 public:
  // Constructors
  CWinThread();
  BOOL CreateThread(DWORD dwCreateFlags = 0, UINT nStackSize = 0,
LPSECURITY_ATTRIBUTES lpSecurityAttrs = NULL);

  // Attributes
  CWnd* m_pMainWnd; // main window (usually same AfxGetApp()->m_pMainWnd)
  CWnd* m_pActiveWnd; // active main window (may not be m_pMainWnd)
  BOOL m_bAutoDelete; // enables 'delete this' after thread termination

  // only valid while running
  HANDLE m_hThread; // this thread's HANDLE
  operator HANDLE() const;
  DWORD m_nThreadID; // this thread's ID

  int GetThreadPriority();
  BOOL SetThreadPriority(int nPriority);

  // Operations
  DWORD SuspendThread();
  DWORD ResumeThread();
  BOOL PostThreadMessage(UINT message, WPARAM wParam, LPARAM lParam);

  // Overridables
  //执行U程实例初始化,必须重写
  virtual BOOL InitInstance();

  // running and idle processing
  //控制U程的函敎ͼ包含消息泵,一般不重写
  virtual int Run();

  //消息调度到TranslateMessage和DispatchMessage之前对其q行{选,
  //通常不重?br />  virtual BOOL PreTranslateMessage(MSG* pMsg);

  virtual BOOL PumpMessage(); // low level message pump

  //执行U程特定的闲|时间处理,通常不重?br />  virtual BOOL OnIdle(LONG lCount); // return TRUE if more idle processing
  virtual BOOL IsIdleMessage(MSG* pMsg); // checks for special messages

  //U程l止时执行清除,通常需要重?br />  virtual int ExitInstance(); // default will 'delete this'

  //截获qE的消息和命令处理程序引发的未处理异常,通常不重?br />  virtual LRESULT ProcessWndProcException(CException* e, const MSG* pMsg);

  // Advanced: handling messages sent to message filter hook
  virtual BOOL ProcessMessageFilter(int code, LPMSG lpMsg);

  // Advanced: virtual access to m_pMainWnd
  virtual CWnd* GetMainWnd();

  // Implementation
 public:
  virtual ~CWinThread();
  #ifdef _DEBUG
   virtual void AssertValid() const;
   virtual void Dump(CDumpContext& dc) const;
   int m_nDisablePumpCount; // Diagnostic trap to detect illegal re-entrancy
  #endif
  void CommonConstruct();
  virtual void Delete();
  // 'delete this' only if m_bAutoDelete == TRUE

  // message pump for Run
  MSG m_msgCur; // current message

 public:
  // constructor used by implementation of AfxBeginThread
  CWinThread(AFX_THREADPROC pfnThreadProc, LPVOID pParam);

  // valid after construction
  LPVOID m_pThreadParams; // generic parameters passed to starting function
  AFX_THREADPROC m_pfnThreadProc;

  // set after OLE is initialized
  void (AFXAPI* m_lpfnOleTermOrFreeLib)(BOOL, BOOL);
  COleMessageFilter* m_pMessageFilter;

 protected:
  CPoint m_ptCursorLast; // last mouse position
  UINT m_nMsgLast; // last mouse message
  BOOL DispatchThreadMessageEx(MSG* msg); // helper
  void DispatchThreadMessage(MSG* msg); // obsolete
};

  启动UIU程的AfxBeginThread函数的原型ؓQ?br />
CWinThread *AfxBeginThread(
 //从CWinThreadz的类?RUNTIME_CLASS
 CRuntimeClass *pThreadClass,
 int nPriority = THREAD_PRIORITY_NORMAL,
 UINT nStackSize = 0,
 DWORD dwCreateFlags = 0,
 LPSECURITY_ATTRIBUTES lpSecurityAttrs = NULL
);

  我们可以方便C用VC++ 6.0cd导定义一个承自CWinThread的用LE类。下面给Z生我们自定义的CWinThread子类CMyUIThread的方法?br />
  打开VC++ 6.0cd|在如下窗口中选择Base ClasscMؓCWinThreadQ输入子cd为CMyUIThreadQ点?OK"按钮后就产生了类CMyUIThread?br />

  其源代码框架为:

/////////////////////////////////////////////////////////////////////////////
// CMyUIThread thread

class CMyUIThread : public CWinThread
{
 DECLARE_DYNCREATE(CMyUIThread)
 protected:
  CMyUIThread(); // protected constructor used by dynamic creation

  // Attributes
 public:

  // Operations
 public:

  // Overrides
  // ClassWizard generated virtual function overrides
  //{{AFX_VIRTUAL(CMyUIThread)
  public:
   virtual BOOL InitInstance();
   virtual int ExitInstance();
  //}}AFX_VIRTUAL

  // Implementation
 protected:
  virtual ~CMyUIThread();

  // Generated message map functions
  //{{AFX_MSG(CMyUIThread)
   // NOTE - the ClassWizard will add and remove member functions here.
  //}}AFX_MSG

 DECLARE_MESSAGE_MAP()
};

/////////////////////////////////////////////////////////////////////////////
// CMyUIThread

IMPLEMENT_DYNCREATE(CMyUIThread, CWinThread)

CMyUIThread::CMyUIThread()
{}

CMyUIThread::~CMyUIThread()
{}

BOOL CMyUIThread::InitInstance()
{
 // TODO: perform and per-thread initialization here
 return TRUE;
}

int CMyUIThread::ExitInstance()
{
 // TODO: perform any per-thread cleanup here
 return CWinThread::ExitInstance();
}

BEGIN_MESSAGE_MAP(CMyUIThread, CWinThread)
//{{AFX_MSG_MAP(CMyUIThread)
// NOTE - the ClassWizard will add and remove mapping macros here.
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

  使用下列代码可以启动这个UIU程Q?br />
CMyUIThread *pThread;
pThread = (CMyUIThread*)
AfxBeginThread( RUNTIME_CLASS(CMyUIThread) );

  另外Q我们也可以不用AfxBeginThread 创徏U程Q而是分如下两步完成:

  Q?Q调用线E类的构造函数创Z个线E对象;

  Q?Q调用CWinThread::CreateThread函数来启动该U程?br />
  在线E自w内调用AfxEndThread函数可以l止该线E:

void AfxEndThread(
 UINT nExitCode //the exit code of the thread
);

  对于UIU程而言Q如果消息队列中攑օ了WM_QUIT消息Q将l束U程?br />
  关于UIU程和工作者线E的分配Q最好的做法是:所有与UI相关的操作放入主U程Q其它的Ua的运工作交l独立的C工作者线E?br />
  候捷先生早些旉喜欢为MDIE序的每个窗口创Z个线E,他后来澄清了q个错误。因为如果ؓMDIE序的每个窗口都单独创徏一个线E,在窗口进行切换的时候,进行线E的上下文切换!
2.U程间通信

  MFC中定义了l承自CSyncObjectcȝCCriticalSection 、CCEvent、CMutex、CSemaphorecd装和化了WIN32 API所提供的界区、事件、互斥和信号量。用这些同步机Ӟ必须包含"Afxmt.h"头文件。下囄Zcȝl承关系Q?br />

  作ؓCSyncObjectcȝl承c,我们仅仅使用基类CSyncObject的接口函数就可以方便、统一的操作CCriticalSection 、CCEvent、CMutex、CSemaphorec,下面是CSyncObjectcȝ原型Q?br />
class CSyncObject : public CObject
{
 DECLARE_DYNAMIC(CSyncObject)

 // Constructor
 public:
  CSyncObject(LPCTSTR pstrName);

  // Attributes
 public:
  operator HANDLE() const;
  HANDLE m_hObject;

  // Operations
  virtual BOOL Lock(DWORD dwTimeout = INFINITE);
  virtual BOOL Unlock() = 0;
  virtual BOOL Unlock(LONG /* lCount */, LPLONG /* lpPrevCount=NULL */)
  { return TRUE; }

  // Implementation
 public:
  virtual ~CSyncObject();
  #ifdef _DEBUG
   CString m_strName;
   virtual void AssertValid() const;
   virtual void Dump(CDumpContext& dc) const;
  #endif
  friend class CSingleLock;
  friend class CMultiLock;
};

  CSyncObjectcL主要的两个函数是Lock和UnlockQ若我们直接使用CSyncObjectcd其派生类Q我们需要非常小心地在Lock之后调用Unlock?br />
  MFC提供的另两个cCSingleLockQ等待一个对象)和CMultiLockQ等待多个对象)为我们编写应用程序提供了更灵zȝ机制Q下面以实际来阐qCSingleLock的用法:

class CThreadSafeWnd
{
 public:
  CThreadSafeWnd(){}
  ~CThreadSafeWnd(){}
  void SetWindow(CWnd *pwnd)
  {
   m_pCWnd = pwnd;
  }
  void PaintBall(COLORREF color, CRect &rc);
 private:
  CWnd *m_pCWnd;
  CCriticalSection m_CSect;
};

void CThreadSafeWnd::PaintBall(COLORREF color, CRect &rc)
{
 CSingleLock csl(&m_CSect);
 //~省的Timeout是INFINITEQ只有m_Csect被激z,csl.Lock()才能q回
 //trueQ这里一直等?br /> if (csl.Lock())
;
 {
  // not necessary
  //AFX_MANAGE_STATE(AfxGetStaticModuleState( ));
  CDC *pdc = m_pCWnd->GetDC();
  CBrush brush(color);
  CBrush *oldbrush = pdc->SelectObject(&brush);
  pdc->Ellipse(rc);
  pdc->SelectObject(oldbrush);
  GdiFlush(); // don't wait to update the display
 }
}

  上述实例讲述了用CSingleLock对Windows GDI相关对象q行保护的方法,下面再给Z个其他方面的例子Q?br />
int array1[10], array2[10];
CMutexSection section; //创徏一个CMutexcȝ对象

//赋值线E控制函?br />UINT EvaluateThread(LPVOID param)
{
 CSingleLock singlelock;
 singlelock(&section);

 //互斥区域
 singlelock.Lock();
 for (int i = 0; i < 10; i++)
  array1[i] = i;
 singlelock.Unlock();
}
//拯U程控制函数
UINT CopyThread(LPVOID param)
{
 CSingleLock singlelock;
 singlelock(&section);

 //互斥区域
 singlelock.Lock();
 for (int i = 0; i < 10; i++)
  array2[i] = array1[i];
 singlelock.Unlock();
}
}

AfxBeginThread(EvaluateThread, NULL); //启动赋值线E?br />AfxBeginThread(CopyThread, NULL); //启动拯U程

   上面的例子中启动了两个线EEvaluateThread和CopyThreadQ线EEvaluateThread?0个数赋值给数组array1 []Q线ECopyThread数larray1[]拯l数larray2[]。由于数l的拯和赋值都是整体行为,如果不以互斥形式执行代码D:

for (int i = 0; i < 10; i++)
array1[i] = i;

  ?br />
for (int i = 0; i < 10; i++)
array2[i] = array1[i];

  其结果是很难预料的!

  除了可用CCriticalSection、CEvent、CMutex、CSemaphore作ؓU程间同步通信的方式以外,我们q可以利用PostThreadMessage函数在线E间发送消息:

BOOL PostThreadMessage(DWORD idThread, // thread identifier
UINT Msg, // message to post
WPARAM wParam, // first message parameter
LPARAM lParam // second message parameter
);
3.U程与消息队?br />
  在WIN32中,每一个线E都对应着一个消息队列。由于一个线E可以生数个窗口,所以ƈ不是每个H口都对应着一个消息队列。下列几句话应该作ؓ"定理"被记住:

  "定理" 一

  所有生给某个H口的消息,都先由创个窗口的U程处理Q?br />
  "定理" ?br />
  Windows屏幕上的每一个控仉是一个窗口,有对应的H口函数?br />
  消息的发送通常有两U方式,一是SendMessageQ一是PostMessageQ其原型分别为:

LRESULT SendMessage(HWND hWnd, // handle of destination window
 UINT Msg, // message to send
 WPARAM wParam, // first message parameter
 LPARAM lParam // second message parameter
);
BOOL PostMessage(HWND hWnd, // handle of destination window
 UINT Msg, // message to post
 WPARAM wParam, // first message parameter
 LPARAM lParam // second message parameter
);

   两个函数原型中的四个参数的意义相同,但是SendMessage和PostMessage的行为有差异。SendMessage必须{待消息被处理后 才返回,而PostMessage仅仅消息放入消息队列。SendMessage的目标窗口如果属于另一个线E,则会发生U程上下文切换,{待另一U程 处理完成消息。ؓ了防止另一U程当掉Q导致SendMessage永远不能q回Q我们可以调用SendMessageTimeout函数Q?br />
LRESULT SendMessageTimeout(
 HWND hWnd, // handle of destination window
 UINT Msg, // message to send
 WPARAM wParam, // first message parameter
 LPARAM lParam, // second message parameter
 UINT fuFlags, // how to send the message
 UINT uTimeout, // time-out duration
 LPDWORD lpdwResult // return value for synchronous call
);

  4. MFCU程、消息队列与MFCE序?生死因果"

  分析MFCE序的主U程启动及消息队列处理的q程有助于我们q一步理解UIU程与消息队列的关系Qؓ此我们需要简单地叙述一下MFCE序?生死因果"Q侯P《深入浅出MFC》)?br />
  使用VC++ 6.0的向导完成一个最单的单文架构MFC应用E序MFCThreadQ?br />
  Q?Q?输入MFC EXE工程名MFCThreadQ?br />
  Q?Q?选择单文档架构,不支持Document/Viewl构Q?br />
  Q?Q?ActiveX?D container{其他选项都选择无?br />
  我们来分析这个工E。下面是产生的核心源代码Q?br />
  MFCThread.h 文g

class CMFCThreadApp : public CWinApp
{
 public:
  CMFCThreadApp();

  // Overrides
  // ClassWizard generated virtual function overrides
  //{{AFX_VIRTUAL(CMFCThreadApp)
   public:
    virtual BOOL InitInstance();
  //}}AFX_VIRTUAL

  // Implementation

 public:
  //{{AFX_MSG(CMFCThreadApp)
   afx_msg void OnAppAbout();
   // NOTE - the ClassWizard will add and remove member functions here.
   // DO NOT EDIT what you see in these blocks of generated code !
  //}}AFX_MSG
 DECLARE_MESSAGE_MAP()
};

  MFCThread.cpp文g

CMFCThreadApp theApp;

/////////////////////////////////////////////////////////////////////////////
// CMFCThreadApp initialization

BOOL CMFCThreadApp::InitInstance()
{
 ?br /> CMainFrame* pFrame = new CMainFrame;
 m_pMainWnd = pFrame;

 // create and load the frame with its resources
 pFrame->LoadFrame(IDR_MAINFRAME,WS_OVERLAPPEDWINDOW | FWS_ADDTOTITLE, NULL,NULL);
 // The one and only window has been initialized, so show and update it.
 pFrame->ShowWindow(SW_SHOW);
 pFrame->UpdateWindow();

 return TRUE;
}

  MainFrm.h文g

#include "ChildView.h"

class CMainFrame : public CFrameWnd
{
 public:
  CMainFrame();
 protected:
  DECLARE_DYNAMIC(CMainFrame)

  // Attributes
 public:

  // Operations
 public:
  // Overrides
  // ClassWizard generated virtual function overrides
  //{{AFX_VIRTUAL(CMainFrame)
   virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
   virtual BOOL OnCmdMsg(UINT nID, int nCode, void* pExtra, AFX_CMDHANDLERINFO* pHandlerInfo);
  //}}AFX_VIRTUAL

  // Implementation
 public:
  virtual ~CMainFrame();
  #ifdef _DEBUG
   virtual void AssertValid() const;
   virtual void Dump(CDumpContext& dc) const;
  #endif
  CChildView m_wndView;

  // Generated message map functions
 protected:
 //{{AFX_MSG(CMainFrame)
  afx_msg void OnSetFocus(CWnd *pOldWnd);
  // NOTE - the ClassWizard will add and remove member functions here.
  // DO NOT EDIT what you see in these blocks of generated code!
 //}}AFX_MSG
 DECLARE_MESSAGE_MAP()
};

  MainFrm.cpp文g

IMPLEMENT_DYNAMIC(CMainFrame, CFrameWnd)

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
 //{{AFX_MSG_MAP(CMainFrame)
  // NOTE - the ClassWizard will add and remove mapping macros here.
  // DO NOT EDIT what you see in these blocks of generated code !
  ON_WM_SETFOCUS()
 //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMainFrame construction/destruction

CMainFrame::CMainFrame()
{
 // TODO: add member initialization code here
}

CMainFrame::~CMainFrame()
{}

BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)
{
 if( !CFrameWnd::PreCreateWindow(cs) )
  return FALSE;
  // TODO: Modify the Window class or styles here by modifying
  // the CREATESTRUCT cs

 cs.dwExStyle &= ~WS_EX_CLIENTEDGE;
 cs.lpszClass = AfxRegisterWndClass(0);
 return TRUE;
}

  ChildView.h文g

// CChildView window

class CChildView : public CWnd
{
 // Construction
 public:
  CChildView();

  // Attributes
 public:
  // Operations
 public:
  // Overrides
  // ClassWizard generated virtual function overrides
  //{{AFX_VIRTUAL(CChildView)
   protected:
    virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
  //}}AFX_VIRTUAL

  // Implementation
 public:
  virtual ~CChildView();

  // Generated message map functions
 protected:
  //{{AFX_MSG(CChildView)
   afx_msg void OnPaint();
  //}}AFX_MSG
 DECLARE_MESSAGE_MAP()
};

ChildView.cpp文g
// CChildView

CChildView::CChildView()
{}

CChildView::~CChildView()
{}

BEGIN_MESSAGE_MAP(CChildView,CWnd )
//{{AFX_MSG_MAP(CChildView)
ON_WM_PAINT()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CChildView message handlers

BOOL CChildView::PreCreateWindow(CREATESTRUCT& cs)
{
 if (!CWnd::PreCreateWindow(cs))
  return FALSE;

 cs.dwExStyle |= WS_EX_CLIENTEDGE;
 cs.style &= ~WS_BORDER;
 cs.lpszClass = AfxRegisterWndClass(CS_HREDRAW|CS_VREDRAW|CS_DBLCLKS,::LoadCursor(NULL, IDC_ARROW),
HBRUSH(COLOR_WINDOW+1),NULL);

 return TRUE;
}

void CChildView::OnPaint()
{
 CPaintDC dc(this); // device context for painting

 // TODO: Add your message handler code here
 // Do not call CWnd::OnPaint() for painting messages
}

   文gMFCThread.h和MFCThread.cpp定义和实现的cCMFCThreadAppl承自CWinAppc,而CWinAppcdl承 自CWinThreadc(CWinThreadcdl承自CCmdTargetc)Q所以CMFCThread本质上是一个MFCU程c,下图l出了相 关的cdơ结构:

我们提取CWinAppcd型的一部分Q?br />
class CWinApp : public CWinThread
{
 DECLARE_DYNAMIC(CWinApp)
 public:
  // Constructor
  CWinApp(LPCTSTR lpszAppName = NULL);// default app name
  // Attributes
  // Startup args (do not change)
  HINSTANCE m_hInstance;
  HINSTANCE m_hPrevInstance;
  LPTSTR m_lpCmdLine;
  int m_nCmdShow;
  // Running args (can be changed in InitInstance)
  LPCTSTR m_pszAppName; // human readable name
  LPCTSTR m_pszExeName; // executable name (no spaces)
  LPCTSTR m_pszHelpFilePath; // default based on module path
  LPCTSTR m_pszProfileName; // default based on app name

  // Overridables
  virtual BOOL InitApplication();
  virtual BOOL InitInstance();
  virtual int ExitInstance(); // return app exit code
  virtual int Run();
  virtual BOOL OnIdle(LONG lCount); // return TRUE if more idle processing
  virtual LRESULT ProcessWndProcException(CException* e,const MSG* pMsg);

 public:
  virtual ~CWinApp();
 protected:
  DECLARE_MESSAGE_MAP()
};

  SDKE序的WinMain 所完成的工作现在由CWinApp 的三个函数完成:

virtual BOOL InitApplication();
virtual BOOL InitInstance();
virtual int Run();

   "CMFCThreadApp theApp;"语句定义的全局变量theApp是整个程式的application objectQ每一个MFC 应用E序都有一个。当我们执行MFCThreadE序的时候,q个全局变量被构造。theApp 配置完成后,WinMain开始执行。但是程序中q没有WinMain的代码,它在哪里呢?原来MFC早已准备好ƈ由Linker直接加到应用E序代码? 的,其原型ؓQ存在于VC++6.0安装目录下提供的APPMODUL.CPP文g中)Q?br />
extern "C" int WINAPI
_tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPTSTR lpCmdLine, int nCmdShow)
{
 // call shared/exported WinMain
 return AfxWinMain(hInstance, hPrevInstance, lpCmdLine, nCmdShow);
}

  其中调用的AfxWinMain如下Q存在于VC++6.0安装目录下提供的WINMAIN.CPP文g中)Q?br />
int AFXAPI AfxWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPTSTR lpCmdLine, int nCmdShow)
{
 ASSERT(hPrevInstance == NULL);

 int nReturnCode = -1;
 CWinThread* pThread = AfxGetThread();
 CWinApp* pApp = AfxGetApp();

 // AFX internal initialization
 if (!AfxWinInit(hInstance, hPrevInstance, lpCmdLine, nCmdShow))
  goto InitFailure;

 // App global initializations (rare)
 if (pApp != NULL && !pApp->InitApplication())
  goto InitFailure;

 // Perform specific initializations
 if (!pThread->InitInstance())
 {
  if (pThread->m_pMainWnd != NULL)
  {
   TRACE0("Warning: Destroying non-NULL m_pMainWnd\n");
   pThread->m_pMainWnd->DestroyWindow();
  }
  nReturnCode = pThread->ExitInstance();
  goto InitFailure;
 }
 nReturnCode = pThread->Run();

 InitFailure:
 #ifdef _DEBUG
  // Check for missing AfxLockTempMap calls
  if (AfxGetModuleThreadState()->m_nTempMapLock != 0)
  {
   TRACE1("Warning: Temp map lock count non-zero (%ld).\n",
AfxGetModuleThreadState()->m_nTempMapLock);
  }
  AfxLockTempMaps();
  AfxUnlockTempMaps(-1);
 #endif

 AfxWinTerm();
 return nReturnCode;
}

  我们提取dQ实际上Q这个函数做的事情主要是Q?br />
CWinThread* pThread = AfxGetThread();
CWinApp* pApp = AfxGetApp();
AfxWinInit(hInstance, hPrevInstance, lpCmdLine, nCmdShow)
pApp->InitApplication()
pThread->InitInstance()
pThread->Run();

   其中QInitApplication 是注册窗口类别的场所QInitInstance是生窗口ƈ昄H口的场所QRun是提取ƈ分派消息的场所。这PMFC同WIN32 SDKE序对应h了。CWinThread::Run是程序生命的"zL源头"Q侯P《深入浅出MFC》,函数存在于VC++ 6.0安装目录下提供的THRDCORE.CPP文g中)Q?br />
// main running routine until thread exits
int CWinThread::Run()
{
 ASSERT_VALID(this);

 // for tracking the idle time state
 BOOL bIdle = TRUE;
 LONG lIdleCount = 0;

 // acquire and dispatch messages until a WM_QUIT message is received.
 for (;;)
 {
  // phase1: check to see if we can do idle work
  while (bIdle && !::PeekMessage(&m_msgCur, NULL, NULL, NULL, PM_NOREMOVE))
  {
   // call OnIdle while in bIdle state
   if (!OnIdle(lIdleCount++))
    bIdle = FALSE; // assume "no idle" state
  }

  // phase2: pump messages while available
  do
  {
   // pump message, but quit on WM_QUIT
   if (!PumpMessage())
    return ExitInstance();

   // reset "no idle" state after pumping "normal" message
   if (IsIdleMessage(&m_msgCur))
   {
    bIdle = TRUE;
    lIdleCount = 0;
   }

  } while (::PeekMessage(&m_msgCur, NULL, NULL, NULL, PM_NOREMOVE));
 }
 ASSERT(FALSE); // not reachable
}

  其中的PumpMessage函数又对应于Q?br />
/////////////////////////////////////////////////////////////////////////////
// CWinThread implementation helpers

BOOL CWinThread::PumpMessage()
{
 ASSERT_VALID(this);

 if (!::GetMessage(&m_msgCur, NULL, NULL, NULL))
 {
  return FALSE;
 }

 // process this message
 if(m_msgCur.message != WM_KICKIDLE && !PreTranslateMessage(&m_msgCur))
 {
  ::TranslateMessage(&m_msgCur);
  ::DispatchMessage(&m_msgCur);
 }
 return TRUE;
}

  因此Q忽略IDLE状态,整个RUN的执行提取主q就是:

do {
 ::GetMessage(&msg,...);
 PreTranslateMessage{&msg);
 ::TranslateMessage(&msg);
 ::DispatchMessage(&msg);
 ...
} while (::PeekMessage(...));

  由此Q我们徏立了MFC消息获取和派生机制与WIN32 SDKE序之间的对应关pR下面l分析MFC消息?l行"q程?br />
   在MFC中,只要是CWnd 衍生cdQ就可以拦下MWindows消息。与H口无关的MFCcdQ例如CDocument 和CWinAppQ如果也惛_理消息,必须衍生自CCmdTargetQƈ且只可能收到WM_COMMAND消息。所有能q行MESSAGE_MAP的类 都承自CCmdTargetQ如Q?br />

  MFC中MESSAGE_MAP的定义依赖于以下三个宏:

DECLARE_MESSAGE_MAP()

BEGIN_MESSAGE_MAP(
 theClass, //Specifies the name of the class whose message map this is
 baseClass //Specifies the name of the base class of theClass
)

END_MESSAGE_MAP()

  我们E序中涉及到的有QMFCThread.h、MainFrm.h、ChildView.h文g

DECLARE_MESSAGE_MAP()
MFCThread.cpp文g
BEGIN_MESSAGE_MAP(CMFCThreadApp, CWinApp)
//{{AFX_MSG_MAP(CMFCThreadApp)
ON_COMMAND(ID_APP_ABOUT, OnAppAbout)
// NOTE - the ClassWizard will add and remove mapping macros here.
// DO NOT EDIT what you see in these blocks of generated code!
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
MainFrm.cpp文g
BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
//{{AFX_MSG_MAP(CMainFrame)
// NOTE - the ClassWizard will add and remove mapping macros here.
// DO NOT EDIT what you see in these blocks of generated code !
ON_WM_SETFOCUS()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
ChildView.cpp文g
BEGIN_MESSAGE_MAP(CChildView,CWnd )
//{{AFX_MSG_MAP(CChildView)
ON_WM_PAINT()
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

  p些宏QMFC建立了一个消息映表Q消息流动网Q,按照消息动|匹配对应的消息处理函数Q完成整个消息的"l行"?br />
  看到q里怿你有q样的疑问:E序定义了CWinAppcȝtheApp全局变量Q可是从来没有调用AfxBeginThread或theApp.CreateThread启动U程呀QtheApp对应的线E是怎么启动的?

  {:MFC在这里用了很高明的一招。实际上Q程序开始运行,W一个线E是由操作系l(OSQ启动的Q在CWinApp的构造函数里QMFCtheApp"对应"向了q个U程Q具体的实现是这LQ?br />
CWinApp::CWinApp(LPCTSTR lpszAppName)
{
 if (lpszAppName != NULL)
  m_pszAppName = _tcsdup(lpszAppName);
 else
  m_pszAppName = NULL;

 // initialize CWinThread state
 AFX_MODULE_STATE *pModuleState = _AFX_CMDTARGET_GETSTATE();
 AFX_MODULE_THREAD_STATE *pThreadState = pModuleState->m_thread;
 ASSERT(AfxGetThread() == NULL);
 pThreadState->m_pCurrentWinThread = this;
 ASSERT(AfxGetThread() == this);
 m_hThread = ::GetCurrentThread();
 m_nThreadID = ::GetCurrentThreadId();

 // initialize CWinApp state
 ASSERT(afxCurrentWinApp == NULL); // only one CWinApp object please
 pModuleState->m_pCurrentWinApp = this;
 ASSERT(AfxGetApp() == this);

 // in non-running state until WinMain
 m_hInstance = NULL;
 m_pszHelpFilePath = NULL;
 m_pszProfileName = NULL;
 m_pszRegistryKey = NULL;
 m_pszExeName = NULL;
 m_pRecentFileList = NULL;
 m_pDocManager = NULL;
 m_atomApp = m_atomSystemTopic = NULL; //微Y懒鬼Q或者他认ؓ
 //q样q等含义更明?
 m_lpCmdLine = NULL;
 m_pCmdInfo = NULL;

 // initialize wait cursor state
 m_nWaitCursorCount = 0;
 m_hcurWaitCursorRestore = NULL;

 // initialize current printer state
 m_hDevMode = NULL;
 m_hDevNames = NULL;
 m_nNumPreviewPages = 0; // not specified (defaults to 1)

 // initialize DAO state
 m_lpfnDaoTerm = NULL; // will be set if AfxDaoInit called

 // other initialization
 m_bHelpMode = FALSE;
 m_nSafetyPoolSize = 512; // default size
}

  很显ӞtheApp成员变量都被赋予OS启动的这个当前线E相关的|如代码:

m_hThread = ::GetCurrentThread();//theApp的线E句柄等于当前线E句?
m_nThreadID = ::GetCurrentThreadId();//theApp的线EID{于当前U程ID

   所以CWinAppcd乎只是ؓMFCE序的第一个线E量w定制的Q它不需要也不能被AfxBeginThread? theApp.CreateThread"再次"启动。这是CWinAppcdtheApp全局变量的内涵!如果你要再增加一个UIU程Q不要承类 CWinAppQ而应l承cCWinThread。而参考第1节,׃我们一般以ȝE(在MFCE序里实际上是OS启动的第一个线E)处理所有窗口的 消息Q所以我们几乎没有再启动UIU程的需求!


swo 2006-08-17 22:30 发表评论
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深入出Win32多线E程序设计之基本概念http://www.shnenglu.com/swo2006/articles/11347.htmlswoswoThu, 17 Aug 2006 07:03:00 GMThttp://www.shnenglu.com/swo2006/articles/11347.htmlhttp://www.shnenglu.com/swo2006/comments/11347.htmlhttp://www.shnenglu.com/swo2006/articles/11347.html#Feedback0http://www.shnenglu.com/swo2006/comments/commentRss/11347.htmlhttp://www.shnenglu.com/swo2006/services/trackbacks/11347.html阅读全文

swo 2006-08-17 15:03 发表评论
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