孙鑫MFC笔记教程(3)--MFC应用程序框架

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本文详细解析了MFC单文档应用程序从启动到运行的整个流程，包括构造函数、入口函数、初始化实例、注册窗口类、创建窗口、消息循环等关键步骤。

单文档应用程序启动流程 1.Tess.cpp --> CTestApp theApp 2.Tess.cpp --> CTestApp::CTestApp() 3.APPMODUL.cpp --> _tWinMain() !!! 4.WINMAIN.cpp --> AfxWinMain(); 5.WINMAIN.cpp AfxWinMain() --> InitInstance(); 6.Tess.cpp --> InitInstance(); 7.WINCORE.cpp --> AfxEndDeferRegisterClass();!!! 8.CMainFrm.cpp --> CMainFrame::PreCreateWindow(); 9.WINFRM.cpp CMainFrame::PreCreateWindow() --> CFrameWnd::PreCreateWindow(); 10.WINCORE.cpp --> AfxEndDeferRegisterClass(); 11.WINFRM.cpp --> CFrameWnd::Create();！！！LoadFram 12.WINFRM.cpp CFrameWnd::Create() --> CWnd::CreateEx(); 13.显示 14.更新 15.消息循环 CTestApp theApp -> CWinApp() -> CTestApp() -> _tWinMain() ->CTestApp::InitInstance() -> AfxEndDeferRegisterClass() -> CMainFrame::PreCreateWindow() -> CMainFrame::CreateEx() -> CMainFrame::PreCreateWindow() -> CTestApp::PreCreateWindow()改外观，完成创建窗口其中 AfxEndDeferRegisterClass() 设计窗口类，注册窗口，窗口过程选择的是一个缺省的窗口过程Wndcls.lpfuWndProc = DefWindowProc; CMainFrame::PreCreateWindow() 调用 CFrameWnd::PreCreateWindow() 再注册一次 1.CWND类封装了和窗口相关的类, 设计窗口类：在MFC中预先设计好了几种窗口类，只需要去注册一下就行了 2.任何程序都是以WinMain函数为入口，在MFC中是通过链接器把它链接进来的 3.在MFC的源代码中查找入口函数WinMain(). X:/Program Files/Microsoft Visual Studio/VC98/MFC/SRC APPMODUL.CPP文件中 ------------------------------------------------------------------------ extern "C" int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { //Breakpoint1 // call shared/exported WinMain return AfxWinMain(hInstance, hPrevInstance, lpCmdLine, nCmdShow); } ------------------------------------------------------------------------- TCHAR.H ------------------------------------------------------------------------ #define _tWinMain WinMain ------------------------------------------------------------------------ Test.cpp ------------------------------------------------------------------------ CTestApp::CTestApp() { //Breakpoint2 // TODO: add construction code here, // Place all significant initialization in InitInstance } ------------------------------------------------------------------------ RUNNING: Breakpoint2->Breakpoint1 基类先构造，在构造子类首先进入CTestApp的构造函数,然后才到达_tWinMain()函数 Test.cpp -------------------------------------------------------------------------- CTestApp theApp; //全局对象 //Breakpoint3 -------------------------------------------------------------------------- RUNNING: Breakpoint3->Breakpoint2->Breakpoint1 #include <iostream> using namespace std; //a的值在main函数调用之前就有值了，全局变量或者全局对象 //在main加载的时候就已经为全局分配内存空间，赋上初值 // CPoint pt-->CPoint(){}-->int main() int a = 10; class CPoint { public: CPoint(){} }; CPoint pt; int main() { cout<<a<<endl; return 0; } 4. 在MFC程序中,通过产生一个应用程序类的对象来表示应用程序本身在X:/Program Files/Microsoft Visual Studio/VC98/MFC/SRC搜索WinApp 得到: APPCORE.CPP -------------------------------------------------------------------------- CWinApp::CWinApp(LPCTSTR lpszAppName) //CWinApp的构造函数 { 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; //this指针指向CTestApp对象(theApp) //根据继承性的原理(使用程序测试) 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; 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 } -------------------------------------------------------------------------------- CWinApp的构造函数带有参数LPCTSTR lpszAppName,而CTestApp的构造函数不带有任何参数. 在AFXWIN.H文件中 ----------------------------------------------------------------------------- class CWinApp : public CWinThread { DECLARE_DYNAMIC(CWinApp) public: // Constructor CWinApp(LPCTSTR lpszAppName = NULL); //CWinApp的构造函数有缺省的参数 .............................. } 5. 回到_tWinMain(...)函数查找AfxWinMain()函数,Afx表示应用程序框架类函数,相当于全局函数 WINMAIN.CPP中 ------------------------------------------------------------------------------- int AFXAPI AfxWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { ASSERT(hPrevInstance == NULL); int nReturnCode = -1; CWinThread* pThread = AfxGetThread(); //线程的指针,也是指向子类 CWinApp* pApp = AfxGetApp(); //获得指针,这里pApp指向派生类的指针(theApp) // AFX internal initialization if (!AfxWinInit(hInstance, hPrevInstance, lpCmdLine, nCmdShow)) goto InitFailure; // App global initializations (rare) if (pApp != NULL && !pApp->InitApplication())//pApp->InitApplication()MFC内部 //管理的函数 goto InitFailure; // Perform specific initializations if (!pThread->InitInstance()) //pThread->InitInstance() //Breakpoint4 //在AFXWIN.H中 //virtual BOOL InitInstance(); //InitInstance是一个虚函数 //此时调用的InitInstance函数是 //CTestApp::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();//Run()方法完成我们的消息循环 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; } 6. 在CTestApp的InitInstance()函数设置断点 ------------------------------------------------------------------------------------ BOOL CTestApp::InitInstance() { //Breakpoint5 AfxEnableControlContainer(); ............. } ------------------------------------------------------------------------------------- RUNNING:<1> 定义全局对象 CTestApp theApp; (Breakpoint3) <2> 构造全局对象 CTestApp::CTestApp()(Breakpoint2) <3> 构造基类对象 <4> 进入_tWinMain函数 (Breakpoint1) <5> 到达AfxWinMain函数 if (!pThread->InitInstance()) (Breakpoint4) <6> 到达CTestApp::InitInstance() (Breakpoint5) 7. 注册窗口类 AfxEndDeferRegisterClass函数 WINCORE.CPP中 (注册窗口类应该在PreCreateWindow中调用) 由于是单文档应用程序的原因,事先调用AfxEndDeferRegisterClass函数注册窗口 MFC中创建窗口的时候是注册，而单文档的应用程序是在之前就注册了 ------------------------------------------------------------------------------------- BOOL AFXAPI AfxEndDeferRegisterClass(LONG fToRegister) { // Breakpoint6 // mask off all classes that are already registered AFX_MODULE_STATE* pModuleState = AfxGetModuleState(); fToRegister &= ~pModuleState->m_fRegisteredClasses; if (fToRegister == 0) return TRUE; LONG fRegisteredClasses = 0; ........................ wndcls.lpfnWndProc = DefWindowProc; } ------------------------------------------------------------------------------------- BOOL AFXAPI AfxRegisterClass(WNDCLASS* lpWndClass) { WNDCLASS wndcls; if (GetClassInfo(lpWndClass->hInstance, lpWndClass->lpszClassName, &wndcls)) //判断窗口是否注册 { // class already registered return TRUE; } if (!::RegisterClass(lpWndClass)) //调用RegisterClass,API函数 { TRACE1("Can't register window class named %s/n", lpWndClass->lpszClassName); return FALSE; } ................................................. } ------------------------------------------------------------------------------------- <7> 注册窗口类 BOOL AFXAPI AfxEndDeferRegisterClass(LONG fToRegister) (Breakpoint6) 8. 产生窗口 CMainFrm.CPP ------------------------------------------------------------------------------------- BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs) { (Breakpoint7) if( !CFrameWnd::PreCreateWindow(cs) ) //函数调用 return FALSE; // TODO: Modify the Window class or styles here by modifying // the CREATESTRUCT cs return TRUE; } ------------------------------------------------------------------------------------- <8>BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs) (Breakpoint7) WINFRM.CPP ------------------------------------------------------------------------------------- BOOL CFrameWnd::PreCreateWindow(CREATESTRUCT& cs) { (Breakpoint8) if (cs.lpszClass == NULL) { VERIFY(AfxDeferRegisterClass(AFX_WNDFRAMEORVIEW_REG)); //AfxDeferRegisterClass(AFX_WNDFRAMEORVIEW_REG)判断当前的窗口类有没有 //注册,没有就注册 cs.lpszClass = _afxWndFrameOrView; // COLOR_WINDOW background } if ((cs.style & FWS_ADDTOTITLE) && afxData.bWin4) cs.style |= FWS_PREFIXTITLE; if (afxData.bWin4) cs.dwExStyle |= WS_EX_CLIENTEDGE; return TRUE; } ------------------------------------------------------------------------------------- AFXIMPL.h ------------------------------------------------------------------------------------- #define AfxDeferRegisterClass(fClass) AfxEndDeferRegisterClass(fClass) ------------------------------------------------------------------------------------- <9> BOOL CFrameWnd::PreCreateWindow(CREATESTRUCT& cs) (Breakpoint8) WINCORE.cpp ------------------------------------------------------------------------------------- BOOL CWnd::CreateEx(DWORD dwExStyle, LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, int x, int y, int nWidth, int nHeight, HWND hWndParent, HMENU nIDorHMenu, LPVOID lpParam) { (Breakpoint9) // allow modification of several common create parameters CREATESTRUCT cs; cs.dwExStyle = dwExStyle; cs.lpszClass = lpszClassName; .............................. if (!PreCreateWindow(cs)) //PreCreateWindow是一个虚函数,调用子类的PreCreateWindow（） { PostNcDestroy(); return FALSE; } ............................... } ------------------------------------------------------------------------------------- BOOL CWnd::CreateEx(DWORD dwExStyle, LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID, LPVOID lpParam /* = NULL */) //调用上面的CreateEx函数 { (Breakpoint10) return CreateEx(dwExStyle, lpszClassName, lpszWindowName, dwStyle, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, pParentWnd->GetSafeHwnd(), (HMENU)nID, lpParam); } ------------------------------------------------------------------------------------- WINFRM.CPP ------------------------------------------------------------------------------------- BOOL CFrameWnd::Create(LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, LPCTSTR lpszMenuName, DWORD dwExStyle, CCreateContext* pContext) { (Breakpoint11) .......................... if (!CreateEx(dwExStyle, lpszClassName, lpszWindowName, dwStyle, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, pParentWnd->GetSafeHwnd(), hMenu, (LPVOID)pContext)) //调用上面的 { //CreateEx函数 TRACE0("Warning: failed to create CFrameWnd./n"); if (hMenu != NULL) DestroyMenu(hMenu); return FALSE; } .................................................... } ----------------------------------------------------------------------------------- 9. 显示更新窗口 Test.CPP ----------------------------------------------------------------------------------- m_pMainWnd->ShowWindow(SW_SHOW); m_pMainWnd->UpdateWindow(); //m_pMainWnd指向框架窗口对象的指针 ----------------------------------------------------------------------------------- 10. THRDCORE.CPP ----------------------------------------------------------------------------------- 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 } ------------------------------------------------------------------------------------ BOOL CWinThread::PumpMessage() { ASSERT_VALID(this); if (!::GetMessage(&m_msgCur, NULL, NULL, NULL)) { #ifdef _DEBUG if (afxTraceFlags & traceAppMsg) TRACE0("CWinThread::PumpMessage - Received WM_QUIT./n"); m_nDisablePumpCount++; // application must die // Note: prevents calling message loop things in 'ExitInstance' // will never be decremented #endif return FALSE; } #ifdef _DEBUG if (m_nDisablePumpCount != 0) { TRACE0("Error: CWinThread::PumpMessage called when not permitted./n"); ASSERT(FALSE); } #endif #ifdef _DEBUG if (afxTraceFlags & traceAppMsg) _AfxTraceMsg(_T("PumpMessage"), &m_msgCur); #endif // process this message if (m_msgCur.message != WM_KICKIDLE && !PreTranslateMessage(&m_msgCur)) { ::TranslateMessage(&m_msgCur); ::DispatchMessage(&m_msgCur); } return TRUE; } 11. 窗口过程 (在AfxEndDeferRegisterClass函数中设置) wndcls.lpfnWndProc = DefWindowProc; //缺省的窗口过程 12. 封装一个CWND类 class CWnd { public: BOOL CreateEx(DWORD dwExStyle, // extended window style LPCTSTR lpClassName, // registered class name LPCTSTR lpWindowName, // window name DWORD dwStyle, // window style int x, // horizontal position of window int y, // vertical position of window int nWidth, // window width int nHeight, // window height HWND hWndParent, // handle to parent or owner window HMENU hMenu, // menu handle or child identifier HINSTANCE hInstance, // handle to application instance LPVOID lpParam); // window-creation data BOOL ShowWindow(int nCmdShow); BOOL UpdateWindow(); public: HWND m_hWnd; }; BOOL CWnd::CreateEx(DWORD dwExStyle, // extended window style LPCTSTR lpClassName, // registered class name LPCTSTR lpWindowName, // window name DWORD dwStyle, // window style int x, // horizontal position of window int y, // vertical position of window int nWidth, // window width int nHeight, // window height HWND hWndParent, // handle to parent or owner window HMENU hMenu, // menu handle or child identifier HINSTANCE hInstance, // handle to application instance LPVOID lpParam) // window-creation data { m_hWnd=::CreateWindowEx(dwExStyle,lpClassName,dwStyle,x,y, nWidth,nHeight,hWndParent,hMenu,hInstance, lpParam); if(m_hWnd!=NULL) return TRUE; else return FALSE; } BOOL CWnd::ShowWindow(int nCmdShow) { return ::ShowWindow(m_hWnd,nCmdShow); } BOOL CWnd::UpdateWindow() { return ::UpdateWindow(m_hWnd); } int WINAPI WinMain( HINSTANCE hInstance, // handle to current instance HINSTANCE hPrevInstance, // handle to previous instance LPSTR lpCmdLine, // command line int nCmdShow // show state ) { WNDCLASS wndcls; wndcls.cbClsExtra=0; wndcls.cbWndExtra=0; ...... RegisterClass(&wndcls); CWnd wnd; wnd.CreateEx(...); wnd.ShowWindow(SW_SHOWNORMAL); wnd.UpdateWindow(); //第一堂课讲的内容 HWND hwnd; hwnd=CreateWindowEx(); ::ShowWindow(hwnd,SW_SHOWNORMAL); ::UpdateWindow(hwnd); ...... } 13.CTestView其实也是一个窗口，可以看作是CMainFrame框架窗口的一个子窗口，覆盖在CMainFrame之上 14.CTestDoc : CDocument : CCmdTarget : CObject 不是一个窗口数据存储、加载由CDocument类完成数据显示、修改由CView类完成 15.CMainFrame、CDocument、CView 是如何组织在一起的呢在CTestApp::InitInstance()中定义了一个单文挡指针CSingleDocTempLate* pDocTemplate将这三个类有机组织在一起了，然后用AddDocTemplate(pDocTemplate)；载入文档模板 16.CAbout : CDialog : CWnd : CCmdTarget : CObject 是一个窗口 17.::ShowWindow(), ::表示你调用的是一个全局函数想调用全局函数，sdk函数，都可以用::来引用类内成员函数名与sdk函数名一致，可以用::区分 18.窗口类对象和窗口的关系窗口对象和程序对象不是一回事，窗口销毁了程序不一定就销毁了，程序销毁了，窗口就一定销毁了，和程序析构函数有关窗口与程序相联系的纽带是窗口句柄 HWND hwnd; 也就是说，窗口销毁了，CMainFrame、CView 仍然存活，其内成员函数依然可以调用 CWnd 中就定义有一个HWND结构 m_hwnd，用来保存窗口句柄 19.mfc中结构体也是一个类 20.CMainFrame::OnCreate()中定义一个按钮 { CButton btn; btn.Create("test",WS_CHTID,CRect(0,0,100,100),this,12345); "显示文本",显示类型，显示对角，归属窗口，按钮标志 } 不显示的原因有两个： 1 这里btn是一个局部变量，走出OnCreate()右大括号的时候，对象被销毁了，于是窗口也销毁了也就是前面说的，窗口与对象的存活关系 2 少了窗口显示过程btn.ShowWindow(),也可以在Create()中增加显示类型标志WS_VISIBLE省略该步类内用this指的就是类对象的句柄了 Button 控件其实就是一个窗口，因此在Create()类型时，可以指定窗口类型同时指定按钮类型单选按钮控件、复选按钮控件，其实就是button的不同按钮类型继承于CWnd的button类，与CWnd同样定义有一个HWND结构 m_hwnd，用来保存button窗口句柄,因此一般不用显式地定义另一个HWND结构来保存button窗口句柄，需要就调用就行了 18、CMainFrame的客户区包括了工具栏部分可以看到代码执行结果是按钮把工具栏给遮住了 CView的客户区就是空白部分如果要在CView的客户区中显示，可以把变量定义、代码放入CView类中 21.窗口显示在哪里并不是因为代码放在哪个窗口类代码中，而是看Create()中指定的归属窗口是哪个如果把原显示在CView客户区的代码Create()指定的归属窗口句柄this改为GetParent(), 按钮就显示在CMainFrame客户区中了 GetParent()　api函数，获取父窗口句柄 22.每个窗口类内都定义并维护着一个指向该窗口的句柄