窗口封装

01

BOOL CMFCApp::InitInstance()

02

{

03

    CMFCWin* pMainWnd = new CMFCWin;

04

    if (NULL == pMainWnd)

05

        return FALSE;

07

    CString strWndClass;

08

    strWndClass = AfxRegisterWndClass(CS_HREDRAW|CS_VREDRAW,

09

        ::LoadCursor(NULL, IDC_ARROW), HBRUSH(COLOR_WINDOW+1), NULL);

11

    HMENU hMenu = ::LoadMenu(NULL, MAKEINTRESOURCE(IDR_MAINFRAME));

12

    // Bruce：开始创建主窗口

13

    if (!pMainWnd->CreateEx(WS_EX_APPWINDOW, strWndClass,

14

        _T("MFCBased without Wizzard"), WS_OVERLAPPEDWINDOW,

15

        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,

16

        NULL, hMenu, NULL))

17

    {

18

        AfxMessageBox(_T("CreateEx Failed!"));

19

        return FALSE;

20

    }

22

    m_pMainWnd = pMainWnd;

23

    pMainWnd->ShowWindow(m_nCmdShow);

24

    pMainWnd->UpdateWindow();

26

    return TRUE;

01

BOOL CWnd::CreateEx(DWORD dwExStyle, LPCTSTR lpszClassName,

02

    LPCTSTR lpszWindowName, DWORD dwStyle,

03

    int x, int y, int nWidth, int nHeight,

04

    HWND hWndParent, HMENU nIDorHMenu, LPVOID lpParam)

05

{

06

    // . . .

07

    // Bruce：Hook? 好戏来了。

08

    AfxHookWindowCreate(this);

09

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

10

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

11

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

13

}

01

void AFXAPI AfxHookWindowCreate(CWnd* pWnd)

02

{

03

    // Bruce：这里取的什么数据？

04

    _AFX_THREAD_STATE* pThreadState = _afxThreadState.GetData();

05

    if (pThreadState->m_pWndInit == pWnd)

06

        return;

08

    if (pThreadState->m_hHookOldCbtFilter == NULL)

09

    {

10

        // Bruce：果然，这里装了个WH_CBT钩子

11

        pThreadState->m_hHookOldCbtFilter = ::SetWindowsHookEx(WH_CBT,

12

            _AfxCbtFilterHook, NULL, ::GetCurrentThreadId());

13

        if (pThreadState->m_hHookOldCbtFilter == NULL)

14

            AfxThrowMemoryException();

15

    }

16

    // . . .

17

    pThreadState->m_pWndInit = pWnd;

18

}

01

LRESULT CALLBACK

02

_AfxCbtFilterHook(int code, WPARAM wParam, LPARAM lParam)

03

{

04

    _AFX_THREAD_STATE* pThreadState = _afxThreadState.GetData();

05

    if (code != HCBT_CREATEWND) // Bruce：只关心窗口创建消息，其他跳过

06

    {

07

        // wait for HCBT_CREATEWND just pass others on...

08

        return CallNextHookEx(pThreadState->m_hHookOldCbtFilter, code,

09

            wParam, lParam);

10

    }

11

    // . . .

12

    LPCREATESTRUCT lpcs = ((LPCBT_CREATEWND)lParam)->lpcs;

13

    // . . .

14

    HWND hWnd = (HWND)wParam;

15

    WNDPROC oldWndProc;

16

    if (pWndInit != NULL)

17

    {

18

        AFX_MANAGE_STATE(pWndInit->m_pModuleState);

20

        // Bruce：检查该窗口映射是否存在？后面说明这个函数

21

        ASSERT(CWnd::FromHandlePermanent(hWnd) == NULL);

23

        // Bruce：添加窗口映射（HWND  CWnd）

24

        pWndInit->Attach(hWnd);

25

        // allow other subclassing to occur first

26

        pWndInit->PreSubclassWindow();

28

        WNDPROC *pOldWndProc = pWndInit->GetSuperWndProcAddr();

29

        ASSERT(pOldWndProc != NULL);

31

        // Bruce：subclass，重新设置窗口过程

32

        WNDPROC afxWndProc = AfxGetAfxWndProc();

33

        oldWndProc = (WNDPROC)SetWindowLongPtr(hWnd, GWLP_WNDPROC,

34

                (DWORD_PTR)afxWndProc);

35

        ASSERT(oldWndProc != NULL);

36

        if (oldWndProc != afxWndProc)

37

            *pOldWndProc = oldWndProc;

39

        pThreadState->m_pWndInit = NULL;

40

    }

41

    // . . .

42

}

01

CWnd* PASCAL CWnd::FromHandlePermanent(HWND hWnd)

02

{

03

    CHandleMap* pMap = afxMapHWND();

04

    CWnd* pWnd = NULL;

05

    if (pMap != NULL)

06

    {

07

        // only look in the permanent map - does no allocations

08

        pWnd = (CWnd*)pMap->LookupPermanent(hWnd);

09

        ASSERT(pWnd == NULL || pWnd->m_hWnd == hWnd);

10

    }

11

    return pWnd;

12

}

14

BOOL CWnd::Attach(HWND hWndNew)

15

{

16

    ASSERT(m_hWnd == NULL);     // only attach once, detach on destroy

17

    ASSERT(FromHandlePermanent(hWndNew) == NULL);

18

        // must not already be in permanent map

20

    if (hWndNew == NULL)

21

        return FALSE;

23

    CHandleMap* pMap = afxMapHWND(TRUE); // create map if not exist

24

    ASSERT(pMap != NULL);

26

    pMap->SetPermanent(m_hWnd = hWndNew, this);

27

    // . . .

28

}

01

WNDPROC AFXAPI AfxGetAfxWndProc()

02

{

03

#ifdef _AFXDLL // Bruce：Use MFC in a Shared DLL

04

    return AfxGetModuleState()->m_pfnAfxWndProc; // Bruce：也就是AfxWndProcBase

05

#else // Bruce：Use MFC in a Static Library

06

    return &AfxWndProc;

07

#endif

08

}

10

LRESULT CALLBACK

11

AfxWndProcBase(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)

12

{

13

    AFX_MANAGE_STATE(_afxBaseModuleState.GetData());

14

    return AfxWndProc(hWnd, nMsg, wParam, lParam);

15

}

17

LRESULT CALLBACK

18

AfxWndProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)

19

{

20

    // special message which identifies the window as using AfxWndProc

21

    if (nMsg == WM_QUERYAFXWNDPROC)

22

        return 1;

24

    // Bruce：查找Map，找到HWND对应的CWnd实例

25

    CWnd* pWnd = CWnd::FromHandlePermanent(hWnd);

26

    ASSERT(pWnd != NULL);

27

    ASSERT(pWnd==NULL || pWnd->m_hWnd == hWnd);

28

    if (pWnd == NULL || pWnd->m_hWnd != hWnd)

29

        return ::DefWindowProc(hWnd, nMsg, wParam, lParam);

30

    return AfxCallWndProc(pWnd, hWnd, nMsg, wParam, lParam); // Bruce：有了CWnd，可以调用窗口实例对应的窗口过程

31

}

33

LRESULT AFXAPI AfxCallWndProc(CWnd* pWnd, HWND hWnd, UINT nMsg,

34

    WPARAM wParam = 0, LPARAM lParam = 0)

35

{

36

    _AFX_THREAD_STATE* pThreadState = _afxThreadState.GetData();

37

    MSG oldState = pThreadState->m_lastSentMsg; // save for nesting

38

    pThreadState->m_lastSentMsg.hwnd = hWnd;

39

    pThreadState->m_lastSentMsg.message = nMsg;

40

    pThreadState->m_lastSentMsg.wParam = wParam;

41

    pThreadState->m_lastSentMsg.lParam = lParam;

43

    #ifdef _DEBUG

44

        _AfxTraceMsg(_T("WndProc"), &pThreadState->m_lastSentMsg);

45

    #endif

47

    // Catch exceptions thrown outside the scope of a callback

48

    // in debug builds and warn the user.

49

    LRESULT lResult;

50

    TRY

51

    {

52

        // . . .

53

        // Bruce：“终于找到属于我的窗口过程了！”，WindowProc是一个virtual function，注意与AfxWndProc的区别

54

        lResult = pWnd->WindowProc(nMsg, wParam, lParam);

55

    }

56

// . . .

57

}

01

int APIENTRY _tWinMain(

02

    HINSTANCE hInst,

03

    HINSTANCE /*hInstPrev*/,

04

    LPTSTR pszCmdLine,

05

    int nCmdShow)

06

{

07

    _Module.Init(0, hInst);

09

    HMENU hMenu = ::LoadMenu(_Module.GetResourceInstance(),

10

        MAKEINTRESOURCE(IDR_MENU));

12

    CATLWin mainWnd;

13

    // Bruce：开始创建主窗口

14

    if (!mainWnd.Create(NULL, CWindow::rcDefault,

15

        _T("ATLBased without Wizzard"), 0, 0, (UINT)hMenu))

16

    {

17

        ::MessageBox(NULL, _T("Create Failed"), _T("ATLBased Error"), MB_OK);

18

        return -1;

19

    }

21

    mainWnd.CenterWindow();

22

    mainWnd.ShowWindow(nCmdShow);

23

    mainWnd.UpdateWindow();

25

    MSG msg;

26

    while (::GetMessage(&msg, NULL, 0, 0))

27

    {

28

        ::TranslateMessage(&msg);

29

        ::DispatchMessage(&msg);

30

    }

32

    _Module.Term();

33

    return msg.wParam;

34

}

01

HWND Create(HWND hWndParent, _U_RECT rect = NULL,

02

    LPCTSTR szWindowName = NULL,

03

    DWORD dwStyle = 0, DWORD dwExStyle = 0,

04

    _U_MENUorID MenuOrID = 0U, LPVOID lpCreateParam = NULL)

05

{

06

    if (T::GetWndClassInfo().m_lpszOrigName == NULL)

07

        T::GetWndClassInfo().m_lpszOrigName = GetWndClassName();

08

    ATOM atom = T::GetWndClassInfo().Register(&m_pfnSuperWindowProc);

10

    dwStyle = T::GetWndStyle(dwStyle);

11

    dwExStyle = T::GetWndExStyle(dwExStyle);

13

    // . . .

15

    return CWindowImplBaseT< TBase, TWinTraits >::Create(hWndParent, rect,

16

        szWindowName, dwStyle, dwExStyle, MenuOrID, atom, lpCreateParam);

17

}

01

template

02

HWND CWindowImplBaseT< TBase, TWinTraits >::Create(

03

    HWND hWndParent, _U_RECT rect, LPCTSTR szWindowName,

04

    DWORD dwStyle, DWORD dwExStyle, _U_MENUorID MenuOrID,

05

    ATOM atom, LPVOID lpCreateParam)

06

{

07

    // . . .

08

    // Allocate the thunk structure here, where we can fail gracefully.

09

    result = m_thunk.Init(NULL,NULL);

10

    // . . .

11

    _AtlWinModule.AddCreateWndData(&m_thunk.cd, this);

12

    // . . .

14

    HWND hWnd = ::CreateWindowEx(dwExStyle, MAKEINTATOM(atom),

15

        szWindowName,dwStyle, rect.m_lpRect->left, rect.m_lpRect->top,

16

        rect.m_lpRect->right - rect.m_lpRect->left,

17

        rect.m_lpRect->bottom - rect.m_lpRect->top,

18

        hWndParent, MenuOrID.m_hMenu,

19

        _AtlBaseModule.GetModuleInstance(), lpCreateParam);

21

    ATLASSUME(m_hWnd == hWnd);

23

    return hWnd;

24

}

01

template

02

LRESULT CALLBACK CWindowImplBaseT< TBase, TWinTraits >::

03

StartWindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)

04

{

05

    // Bruce：通过当前的ThreadId遍历_AtlCreateWndData链表，取得先前保存的窗口this指针

06

    CWindowImplBaseT< TBase, TWinTraits >* pThis = (CWindowImplBaseT< TBase, TWinTraits >*)_AtlWinModule.ExtractCreateWndData();

07

    // . . .

08

    // Bruce：这里保存HWND以作后用，thunking过程中将被覆盖掉

09

    pThis->m_hWnd = hWnd;

11

    // Bruce：将静态窗口过程（如果GetWindowProc没被改写，那么就是CWindowImplBaseT::WindowProc）和this指针初始化到thunk中， m_thunk.Init之后，hWnd被替换成this指针

12

    pThis->m_thunk.Init(pThis->GetWindowProc(), pThis);

13

    // Bruce：这里返回的其实是一个_stdcallthunk结构体的首地址，后面会提及

14

    WNDPROC pProc = pThis->m_thunk.GetWNDPROC();

15

    // . . .

16

    // Bruce：进入静态窗口过程

17

    return pProc(hWnd, uMsg, wParam, lParam);

18

}

01

template

02

LRESULT CALLBACK CWindowImplBaseT< TBase, TWinTraits >::WindowProc(

03

    HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)

04

{

05

    // Bruce：hWnd变回this（thunk的功劳）

06

    CWindowImplBaseT< TBase, TWinTraits >* pThis = (CWindowImplBaseT< TBase, TWinTraits >*)hWnd;

07

    // . . .

09

    // Bruce：转换过程到这里结束，找到this的virtual成员函数处理窗口消息

10

    BOOL bRet = pThis->ProcessWindowMessage(pThis->m_hWnd, uMsg, wParam, lParam, lRes, 0);

11

    // . . .

12

}

01

class CWndProcThunk

02

{

03

public:

04

    _AtlCreateWndData cd;

05

    CStdCallThunk thunk;

07

    BOOL Init(WNDPROC proc, void* pThis)

08

    {

09

        return thunk.Init((DWORD_PTR)proc, pThis);

10

    }

11

    WNDPROC GetWNDPROC()

12

    {

13

        return (WNDPROC)thunk.GetCodeAddress();

14

    }

15

};

01

#if defined(_M_IX86)

02

PVOID __stdcall __AllocStdCallThunk(VOID);

03

VOID  __stdcall __FreeStdCallThunk(PVOID);

05

#pragma pack(push,1)    // Bruce：1字节内存对齐方式

06

struct _stdcallthunk

07

{

08

    DWORD   m_mov;          // mov dword ptr [esp+0x4], pThis (esp+0x4 is hWnd)

09

    DWORD   m_this;         //

10

    BYTE    m_jmp;          // jmp WndProc

11

    DWORD   m_relproc;      // relative jmp

12

    BOOL Init(DWORD_PTR proc, void* pThis)

13

    {

14

        m_mov = 0x042444C7;  //C7 44 24 0C

15

        m_this = PtrToUlong(pThis);

16

        m_jmp = 0xe9;

17

        m_relproc = DWORD((INT_PTR)proc - ((INT_PTR)this+sizeof(_stdcallthunk)));

18

        // write block from data cache and

19

        //  flush from instruction cache

20

        FlushInstructionCache(GetCurrentProcess(), this,sizeof(_stdcallthunk));

21

        return TRUE;

22

    }

23

    //some thunks will dynamically allocate the memory for the code

24

    void* GetCodeAddress()

25

    {

26

        return this;

27

    }

28

    void* operator new(size_t)

29

    {

30

        return __AllocStdCallThunk();

31

    }

32

    void operator delete(void* pThunk)

33

    {

34

        __FreeStdCallThunk(pThunk);

35

    }

36

};

37

#pragma pack(pop)

01

LRESULT CALLBACK XWindow::WndProc(HWND hWnd, UINT uMsg,

02

    WPARAM wParam, LPARAM lParam)

03

{

04

    XWindow* pThis = NULL;

05

    if (WM_NCCREATE == uMsg)

06

    {

07

        assert(!::IsBadReadPtr((void*)lParam, sizeof(CREATESTRUCT)));

08

        LPCREATESTRUCT lpcs = reinterpret_cast(lParam);

09

        pThis = static_cast(lpcs->lpCreateParams);

10

        pThis->m_hWnd = hWnd;

12

        assert(!::IsBadReadPtr(pThis, sizeof(XWindow)));

13

        ::SetWindowLongPtr(hWnd, GWLP_USERDATA, reinterpret_cast(pThis));

14

    }

15

    else

16

        pThis = reinterpret_cast(::GetWindowLongPtr(hWnd, GWLP_USERDATA));

18

    if (pThis)

19

        return pThis->MsgProc(hWnd, uMsg, wParam, lParam);

20

    else

21

        return DefWindowProc(hWnd, uMsg, wParam, lParam);

22

}