MFC文档视图结构框架分析

MFC文档视图结构框架分析

1:程序的“导火索”---theApp

CmyApp theApp;

在声明对象的同时，调用其构造函数。按C++的语法，首先要调用其基类Cwinapp的构造函数. 这个文件主要用于应用程序的一些初始化操作。

class CWinApp : public CWinThread

{

DECLARE_DYNAMIC(CWinApp)

public:

// Constructor

CWinApp(LPCTSTR lpszAppName = NULL);

…………

}

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_hLangResourceDLL = 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_eHelpType = afxWinHelp;

m_nSafetyPoolSize = 512; // default size

}

2:theApp之后的隐藏代码，由他控制整个程序的流程。

_tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,

LPTSTR lpCmdLine, int nCmdShow)

{

// call shared/exported WinMain

return AfxWinMain(hInstance, hPrevInstance, lpCmdLine, nCmdShow);

}

其中有宏定义：#define _tWinMain wWinMain

int AFXAPI AfxWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,

LPTSTR lpCmdLine, int nCmdShow)

{

ASSERT(hPrevInstance == NULL);

int nReturnCode = -1;

CWinThread* pThread = AfxGetThread();；// CWinApp是从CWinThread派生的， CWinApp* pApp = AfxGetApp(); //实质上就是pThread==pApp

// AFX internal initialization

if (!AfxWinInit(hInstance, hPrevInstance, lpCmdLine, nCmdShow)) //用于初始化

goto InitFailure;

// App global initializations (rare)

if (pApp != NULL && !pApp->InitApplication()) //用于初始化

goto InitFailure;

// Perform specific initializations

if (!pThread->InitInstance()) //注意多态性virtual BOOL InitInstanc e();

//又因为pThread==pApp，所以调用pApp-> InitInstance()

{

if (pThread->m_pMainWnd != NULL)

{

TRACE(traceAppMsg, 0, "Warning: Destroying non-NULL m_pMainWnd\ n");

pThread->m_pMainWnd->DestroyWindow();

}

nReturnCode = pThread->ExitInstance();

goto InitFailure;

}

nReturnCode = pThread->Run(); //控制消息循环

InitFailure:

#ifdef _DEBUG

// Check for missing AfxLockTempMap calls

if (AfxGetModuleThreadState()->m_nTempMapLock != 0)

{

TRACE(traceAppMsg, 0, "Warning: Temp map lock count non-zero (%ld). \n",

AfxGetModuleThreadState()->m_nTempMapLock);

}

AfxLockTempMaps();

AfxUnlockTempMaps(-1);

#endif

AfxWinTerm();

return nReturnCode;

}

由上面的程序可以看到几个很重要的函数

（1）AfxWinInit(hInstance, hPrevInstance, lpCmdLine, nCmdShow))

goto InitFailure;

(2) pApp->InitApplication())

(3) pThread->InitInstance()

(4) pThread->Run()

其中1，2 也是完成程序的一些初始化工作，4 主要是为了处理消息，3呢，很关键，我们运行时看到的窗口就是从这里产生。下面一一介绍

3:程序自动产生的InitInstance()函数

以下是自动生成的InitInstance()源程序：

BOOL CmyApp::InitInstance()

{

// 如果一个运行在 Windows XP 上的应用程序清单指定要

// 使用 ComCtl32.dll 版本 6 或更高版本来启用可视化方式，

//则需要 InitCommonControls()。否则，将无法创建窗口。

InitCommonControls();

CWinApp::InitInstance();

// 初始化 OLE 库

if (!AfxOleInit())

{

AfxMessageBox(IDP_OLE_INIT_FAILED);

return FALSE;

}

AfxEnableControlContainer();

// 标准初始化

// 如果未使用这些功能并希望减小

// 最终可执行文件的大小，则应移除下列

// 不需要的特定初始化例程

// 更改用于存储设置的注册表项

// TODO: 应适当修改该字符串，

// 例如修改为公司或组织名

SetRegistryKey(_T("应用程序向导生成的本地应用程序"));

LoadStdProfileSettings(4); // 加载标准 INI 文件选项(包括 MRU) // 注册应用程序的文档模板。文档模板

// 将用作文档、框架窗口和视图之间的连接

CMultiDocTemplate* pDocTemplate;

pDocTemplate = new CMultiDocTemplate(IDR_myTYPE,

RUNTIME_CLASS(CmyDoc),

RUNTIME_CLASS(CChildFrame), // 自定义 MDI 子框架

RUNTIME_CLASS(CmyView));

if (!pDocTemplate)

return FALSE;

AddDocTemplate(pDocTemplate);

// 创建主 MDI 框架窗口

CMainFrame* pMainFrame = new CMainFrame;

if (!pMainFrame || !pMainFrame->LoadFrame(IDR_MAINFRAME))

return FALSE;

m_pMainWnd = pMainFrame;

// 仅当具有后缀时才调用 DragAcceptFiles

// 在 MDI 应用程序中，这应在设置 m_pMainWnd 之后立即发生

// 分析标准外壳命令、DDE、打开文件操作的命令行

CCommandLineInfo cmdInfo;

ParseCommandLine(cmdInfo);

// 调度在命令行中指定的命令。如果

// 用 /RegServer、/Register、/Unregserver 或 /Unregister 启动应用程序，则返回 FALSE。

if (!ProcessShellCommand(cmdInfo)) //引发窗口注册

return FALSE;

// 主窗口已初始化，因此显示它并对其进行更新

pMainFrame->ShowWindow(m_nCmdShow);

pMainFrame->UpdateWindow();

return TRUE;

}

其中，注册窗口用到了一下函数，比较长，如下：

BOOL AFXAPI AfxEndDeferRegisterClass(LONG fToRegister)

{

// 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;

// common initialization

WNDCLASS wndcls;

memset(&wndcls, 0, sizeof(WNDCLASS)); // start with NULL defaults

wndcls.lpfnWndProc = DefWindowProc; //窗口处理函数

wndcls.hInstance = AfxGetInstanceHandle();

wndcls.hCursor = afxData.hcurArrow;

INITCOMMONCONTROLSEX init;

init.dwSize = sizeof(init);

// work to register classes as specified by fToRegister, populate fReg isteredClasses as we go

if (fToRegister & AFX_WND_REG)

{

// Child windows - no brush, no icon, safest default class styles wndcls.style = CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;

wndcls.lpszClassName = _afxWnd;

if (AfxRegisterClass(&wndcls))

fRegisteredClasses |= AFX_WND_REG;

}

if (fToRegister & AFX_WNDOLECONTROL_REG)

{

// OLE Control windows - use parent DC for speed

wndcls.style |= CS_PARENTDC | CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;

wndcls.lpszClassName = _afxWndOleControl;

if (AfxRegisterClass(&wndcls))

fRegisteredClasses |= AFX_WNDOLECONTROL_REG;

}

if (fToRegister & AFX_WNDCONTROLBAR_REG)

{

// Control bar windows

wndcls.style = 0; // control bars don't handle double click

wndcls.lpszClassName = _afxWndControlBar;

wndcls.hbrBackground = (HBRUSH)(COLOR_BTNFACE + 1);

if (AfxRegisterClass(&wndcls))

fRegisteredClasses |= AFX_WNDCONTROLBAR_REG;

}

if (fToRegister & AFX_WNDMDIFRAME_REG)

{

// MDI Frame window (also used for splitter window)

wndcls.style = CS_DBLCLKS;

wndcls.hbrBackground = NULL;

if (_AfxRegisterWithIcon(&wndcls, _afxWndMDIFrame, AFX_IDI_STD_MDIF RAME))

fRegisteredClasses |= AFX_WNDMDIFRAME_REG;

}

if (fToRegister & AFX_WNDFRAMEORVIEW_REG)

{

// SDI Frame or MDI Child windows or views - normal colors

wndcls.style = CS_DBLCLKS | CS_HREDRAW | CS_VREDRAW;

wndcls.hbrBackground = (HBRUSH) (COLOR_WINDOW + 1);

if (_AfxRegisterWithIcon(&wndcls, _afxWndFrameOrView, AFX_IDI_STD_F RAME))

fRegisteredClasses |= AFX_WNDFRAMEORVIEW_REG;

}

if (fToRegister & AFX_WNDCOMMCTLS_REG)

{

// this flag is compatible with the old InitCommonControls() API init.dwICC = ICC_WIN95_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WIN95CTLS_M ASK);

fToRegister &= ~AFX_WIN95CTLS_MASK;

}

if (fToRegister & AFX_WNDCOMMCTL_UPDOWN_REG)

{

init.dwICC = ICC_UPDOWN_CLASS;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ UPDOWN_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_TREEVIEW_REG)

{

init.dwICC = ICC_TREEVIEW_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ TREEVIEW_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_TAB_REG)

{

init.dwICC = ICC_TAB_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_

TAB_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_PROGRESS_REG)

{

init.dwICC = ICC_PROGRESS_CLASS;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ PROGRESS_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_LISTVIEW_REG)

{

init.dwICC = ICC_LISTVIEW_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ LISTVIEW_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_HOTKEY_REG)

{

init.dwICC = ICC_HOTKEY_CLASS;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ HOTKEY_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_BAR_REG)

{

init.dwICC = ICC_BAR_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ BAR_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_ANIMATE_REG)

{

init.dwICC = ICC_ANIMATE_CLASS;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_

ANIMATE_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_INTERNET_REG)

{

init.dwICC = ICC_INTERNET_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ INTERNET_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_COOL_REG)

{

init.dwICC = ICC_COOL_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ COOL_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_USEREX_REG)

{

init.dwICC = ICC_USEREX_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ USEREX_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_DATE_REG)

{

init.dwICC = ICC_DATE_CLASSES;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_ DATE_REG);

}

if (fToRegister & AFX_WNDCOMMCTL_LINK_REG)

{

init.dwICC = ICC_LINK_CLASS;

fRegisteredClasses |= _AfxInitCommonControls(&init, AFX_WNDCOMMCTL_

LINK_REG);

}

// save new state of registered controls

pModuleState->m_fRegisteredClasses |= fRegisteredClasses;

// special case for all common controls registered, turn on AFX_WNDCOM MCTLS_REG

if ((pModuleState->m_fRegisteredClasses & AFX_WIN95CTLS_MASK) == AFX_W IN95CTLS_MASK)

{

pModuleState->m_fRegisteredClasses |= AFX_WNDCOMMCTLS_REG;

fRegisteredClasses |= AFX_WNDCOMMCTLS_REG;

}

// must have registered at least as mamy classes as requested

return (fToRegister & fRegisteredClasses) == fToRegister;

}

他是在PreCreateWindow中调用的注册，

BOOL CFrameWnd::PreCreateWindow(CREATESTRUCT& cs)

{

if (cs.lpszClass == NULL)

{

VERIFY(AfxDeferRegisterClass(AFX_WNDFRAMEORVIEW_REG));

cs.lpszClass = _afxWndFrameOrView; // COLOR_WINDOW background

}

if (cs.style & FWS_ADDTOTITLE)

cs.style |= FWS_PREFIXTITLE;

cs.dwExStyle |= WS_EX_CLIENTEDGE;

return TRUE;

}

BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)

{

if( !CFrameWnd::PreCreateWindow(cs) )

return FALSE;

// TODO: Modify the Window class or styles here by modifying

// the CREATESTRUCT cs

return TRUE;

}

BOOL CView::PreCreateWindow(CREATESTRUCT & cs)

{

ASSERT(cs.style & WS_CHILD);

if (cs.lpszClass == NULL)

{

VERIFY(AfxDeferRegisterClass(AFX_WNDFRAMEORVIEW_REG));

cs.lpszClass = _afxWndFrameOrView; // COLOR_WINDOW background }

if (cs.style & WS_BORDER)

{

cs.dwExStyle |= WS_EX_CLIENTEDGE;

cs.style &= ~WS_BORDER;

}

return TRUE;

}

BOOL CTestView::PreCreateWindow(CREATESTRUCT& cs)

{

// TODO: Modify the Window class or styles here by modifying

// the CREATESTRUCT cs

return CView::PreCreateWindow(cs);

}

有几点要说明

（1）m_pMainWnd，头文件里并没有这个变量呀？噢，这个在基类里定义的public 类型的变量，所以，他是通过继承得到的。

(2) 你注意过吗，当我们一点运行，会默认出来一个视图窗口，这是谁调用的呢？哦，就是下面这几行，它调用了opendocument() 函数。

CCommandLineInfo cmdInfo;

ParseCommandLine(cmdInfo);

if (!ProcessShellCommand(cmdInfo))

return FALSE；

（3）这个函数有个关键的地方

CMultiDocTemplate* pDocTemplate;

pDocTemplate = new CMultiDocTemplate(IDR_myTYPE,

RUNTIME_CLASS(CmyDoc),

RUNTIME_CLASS(CChildFrame), // 自定义 MDI 子框架

RUNTIME_CLASS(CmyView));

if (!pDocTemplate)

return FALSE;

AddDocTemplate(pDocTemplate);

通过它，把视图，窗口和文档结合起来。

4:主窗口CMainFrame的创建

(1)通过CMainFrame* pMainFrame = new CMainFrame;

我们得到的是不断调用的基类

CMainFrame::CMainFrame()

{

// TODO: 在此添加成员初始化代码

}

CMDIFrameWnd::CMDIFrameWnd()

{

m_hWndMDIClient = NULL;

}

CFrameWnd::CFrameWnd()

{

ASSERT(m_hWnd == NULL);

m_nWindow = -1; // unknown window ID

m_bAutoMenuEnable = TRUE; // auto enable on by default m_lpfnCloseProc = NULL;

m_hMenuDefault = NULL;

m_hAccelTable = NULL;

m_nIDHelp = 0;

m_nIDTracking = 0;

m_nIDLastMessage = 0;

m_pViewActive = NULL;

m_cModalStack = 0; // initialize modality support m_phWndDisable = NULL;

m_pNotifyHook = NULL;

m_hMenuAlt = NULL;

m_nIdleFlags = 0; // no idle work at start

m_rectBorder.SetRectEmpty();

m_bHelpMode = HELP_INACTIVE; // not in Shift+F1 help mode m_dwPromptContext = 0;

m_pNextFrameWnd = NULL; // not in list yet

m_bInRecalcLayout = FALSE;

m_pFloatingFrameClass = NULL;

m_nShowDelay = -1; // no delay pending

AddFrameWnd();

}

(2)pMainFrame->LoadFrame(IDR_MAINFRAME)所引发的一系列

BOOL CMDIFrameWnd::LoadFrame(UINT nIDResource, DWORD dwDefaultStyle,

CWnd* pParentWnd, CCreateContext* pContext)

{

if (!CFrameWnd::LoadFrame(nIDResource, dwDefaultStyle,

pParentWnd, pContext))

return FALSE;

// save menu to use when no active MDI child window is present ASSERT(m_hWnd != NULL);

m_hMenuDefault = ::GetMenu(m_hWnd);

if (m_hMenuDefault == NULL)

TRACE(traceAppMsg, 0, "Warning: CMDIFrameWnd without a default menu. \n");

return TRUE;

}

BOOL CFrameWnd::LoadFrame(UINT nIDResource, DWORD dwDefaultStyle,

CWnd* pParentWnd, CCreateContext* pContext)

{

// only do this once

ASSERT_VALID_IDR(nIDResource);

ASSERT(m_nIDHelp == 0 || m_nIDHelp == nIDResource);

m_nIDHelp = nIDResource; // ID for help context (+HID_BASE_RESOURC E)

CString strFullString;

if (strFullString.LoadString(nIDResource))

AfxExtractSubString(m_strTitle, strFullString, 0); // first sub-string

VERIFY(AfxDeferRegisterClass(AFX_WNDFRAMEORVIEW_REG));

// attempt to create the window

LPCTSTR lpszClass = GetIconWndClass(dwDefaultStyle, nIDResource);

CString strTitle = m_strTitle;

if(!Create(lpszClass, strTitle, dwDefaultStyle, rectDefault, pParentWnd, MAKEINTRESOURCE(nIDResource), 0L, pContext))

{

return FALSE; // will self destruct on failure normally }

// save the default menu handle

ASSERT(m_hWnd != NULL);

m_hMenuDefault = ::GetMenu(m_hWnd);

// load accelerator resource

LoadAccelTable(MAKEINTRESOURCE(nIDResource));

if (pContext == NULL) // send initial update

SendMessageToDescendants(WM_INITIALUPDATE, 0, 0, TRUE, TRUE);

return TRUE;

}

BOOL CFrameWnd::Create(LPCTSTR lpszClassName,

LPCTSTR lpszWindowName,

DWORD dwStyle,

const RECT& rect,

CWnd* pParentWnd,

LPCTSTR lpszMenuName,

DWORD dwExStyle,

CCreateContext* pContext)

{

HMENU hMenu = NULL;

if (lpszMenuName != NULL)

{

// load in a menu that will get destroyed when window gets destroye d

HINSTANCE hInst = AfxFindResourceHandle(lpszMenuName, RT_MENU);

if ((hMenu = ::LoadMenu(hInst, lpszMenuName)) == NULL) {

TRACE(traceAppMsg, 0, "Warning: failed to load menu for CFrameW nd.\n");

PostNcDestroy(); // perhaps delete the C++ object return FALSE;

}

}

m_strTitle = lpszWindowName; // save title for later

if (!CreateEx(dwExStyle, lpszClassName, lpszWindowName, dwStyle, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.to p,

pParentWnd->GetSafeHwnd(), hMenu, (LPVOID)pContext))

{

TRACE(traceAppMsg, 0, "Warning: failed to create CFrameWnd.\n");

if (hMenu != NULL)

DestroyMenu(hMenu);

return FALSE;

}

return TRUE;

}

因为CFrameWnd没有重新写CreateEX,所以是调用的基类的CreateEx的函数：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)

{

// allow modification of several common create parameters

CREATESTRUCT cs;

cs.dwExStyle = dwExStyle;

cs.lpszClass = lpszClassName;

cs.lpszName = lpszWindowName;

cs.style = dwStyle;

cs.x = x;

cs.y = y;

cs.cx = nWidth;

cs.cy = nHeight;

cs.hwndParent = hWndParent;

cs.hMenu = nIDorHMenu;

cs.hInstance = AfxGetInstanceHandle();

cs.lpCreateParams = lpParam;

if (!PreCreateWindow(cs))

{

PostNcDestroy();

return FALSE;

}

AfxHookWindowCreate(this);

HWND hWnd = ::CreateWindowEx(cs.dwExStyle, cs.lpszClass,

cs.lpszName, cs.style, cs.x, cs.y, cs.cx, cs.cy,

cs.hwndParent, cs.hMenu, cs.hInstance, cs.lpCreateParams);

#ifdef _DEBUG

if (hWnd == NULL)

{

TRACE(traceAppMsg, 0, "Warning: Window creation failed: GetLastErro r returns 0x%8.8X\n",

GetLastError());

}

#endif

if (!AfxUnhookWindowCreate())

PostNcDestroy(); // cleanup if CreateWindowEx fails too soon

if (hWnd == NULL)

return FALSE;

ASSERT(hWnd == m_hWnd); // should have been set in send msg hook return TRUE;

}

可以看到，::CreateWindowEx是一个全局的函数，在其中触发WM_CREATE消息，进而调用我们自己定义的CMainFrame::OnCreate()

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)

{

if (CMDIFrameWnd::OnCreate(lpCreateStruct) == -1)

return -1;

if (!m_wndToolBar.CreateEx(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE | CBRS_TOP

| CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) || !m_wndToolBar.LoadToolBar(IDR_MAINFRAME))