CWindowWnd类源码分析

CWindowWnd代码在UIBase.h和UIBase.cpp文件里。主要实现的是一个基本窗口的创建与消息处理。

相关代码：

头文件：

class UILIB_API CWindowWnd
    {
    public:
        CWindowWnd();

        HWND GetHWND() const;
        operator HWND() const;

        bool RegisterWindowClass();
        bool RegisterSuperclass();

        HWND Create(HWND hwndParent, LPCTSTR pstrName, DWORD dwStyle, DWORD dwExStyle, const RECT rc, HMENU hMenu = NULL);
        HWND Create(HWND hwndParent, LPCTSTR pstrName, DWORD dwStyle, DWORD dwExStyle, int x = CW_USEDEFAULT, int y = CW_USEDEFAULT, int cx = CW_USEDEFAULT, int cy = CW_USEDEFAULT, HMENU hMenu = NULL);
        HWND CreateDuiWindow(HWND hwndParent, LPCTSTR pstrWindowName,DWORD dwStyle =0, DWORD dwExStyle =0);
        HWND Subclass(HWND hWnd);
        void Unsubclass();
        void ShowWindow(bool bShow = true, bool bTakeFocus = true);
        UINT ShowModal();
        void Close(UINT nRet = IDOK);
        void CenterWindow();    // 居中，支持扩展屏幕
        void SetIcon(UINT nRes);

        LRESULT SendMessage(UINT uMsg, WPARAM wParam = 0, LPARAM lParam = 0L);
        LRESULT PostMessage(UINT uMsg, WPARAM wParam = 0, LPARAM lParam = 0L);
        void ResizeClient(int cx = -1, int cy = -1);

    protected:
        virtual LPCTSTR GetWindowClassName() const = 0;
        virtual LPCTSTR GetSuperClassName() const;
        virtual UINT GetClassStyle() const;

        virtual LRESULT HandleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam);
        virtual void OnFinalMessage(HWND hWnd);

        static LRESULT CALLBACK __WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
        static LRESULT CALLBACK __ControlProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

    protected:
        HWND m_hWnd;
        WNDPROC m_OldWndProc;
        bool m_bSubclassed;
    };

源文件：

//////////////////////////////////////////////////////////////////////////
///
CWindowWnd::CWindowWnd() : m_hWnd(NULL), m_OldWndProc(::DefWindowProc), m_bSubclassed(false)
{
}

HWND CWindowWnd::GetHWND() const 
{ 
    return m_hWnd; 
}

UINT CWindowWnd::GetClassStyle() const
{
    return 0;
}

LPCTSTR CWindowWnd::GetSuperClassName() const
{
    return NULL;
}

CWindowWnd::operator HWND() const
{
    return m_hWnd;
}

HWND CWindowWnd::CreateDuiWindow( HWND hwndParent, LPCTSTR pstrWindowName,DWORD dwStyle /*=0*/, DWORD dwExStyle /*=0*/ )
{
    return Create(hwndParent,pstrWindowName,dwStyle,dwExStyle,0,0,0,0,NULL);
}

HWND CWindowWnd::Create(HWND hwndParent, LPCTSTR pstrName, DWORD dwStyle, DWORD dwExStyle, const RECT rc, HMENU hMenu)
{
    return Create(hwndParent, pstrName, dwStyle, dwExStyle, rc.left, rc.top, rc.right - rc.left, rc.bottom - rc.top, hMenu);
}

//调用创建win32创建窗口的API
//如果是控件则GetSuperClassName返回非NULL 调用RegisterSuperclass
//否则调用RegisterWindowClass
//然后使用CreateWindowEx创建窗口
HWND CWindowWnd::Create(HWND hwndParent, LPCTSTR pstrName, DWORD dwStyle, DWORD dwExStyle, int x, int y, int cx, int cy, HMENU hMenu)
{
    if( GetSuperClassName() != NULL && !RegisterSuperclass() ) return NULL;
    if( GetSuperClassName() == NULL && !RegisterWindowClass() ) return NULL;
    m_hWnd = ::CreateWindowEx(dwExStyle, GetWindowClassName(), pstrName, dwStyle, x, y, cx, cy, hwndParent, hMenu, CPaintManagerUI::GetInstance(), this);
    ASSERT(m_hWnd!=NULL);
    return m_hWnd;
}

//子类化一个控件 m_OldWndProc 保存旧消息处理函数
HWND CWindowWnd::Subclass(HWND hWnd)
{
    ASSERT(::IsWindow(hWnd));
    ASSERT(m_hWnd==NULL);
    m_OldWndProc = SubclassWindow(hWnd, __WndProc);
    if( m_OldWndProc == NULL ) return NULL;
    m_bSubclassed = true;
    m_hWnd = hWnd;
    ::SetWindowLongPtr(hWnd, GWLP_USERDATA, reinterpret_cast<LPARAM>(this));
    return m_hWnd;
}

//恢复之类化的控件
void CWindowWnd::Unsubclass()
{
    ASSERT(::IsWindow(m_hWnd));
    if( !::IsWindow(m_hWnd) ) return;
    if( !m_bSubclassed ) return;
    SubclassWindow(m_hWnd, m_OldWndProc);
    m_OldWndProc = ::DefWindowProc;
    m_bSubclassed = false;
}

void CWindowWnd::ShowWindow(bool bShow /*= true*/, bool bTakeFocus /*= false*/)
{
    ASSERT(::IsWindow(m_hWnd));
    if( !::IsWindow(m_hWnd) ) return;
    ::ShowWindow(m_hWnd, bShow ? (bTakeFocus ? SW_SHOWNORMAL : SW_SHOWNOACTIVATE) : SW_HIDE);
}

//实现一个modal窗口 
UINT CWindowWnd::ShowModal()
{
    ASSERT(::IsWindow(m_hWnd));
    UINT nRet = 0;
    HWND hWndParent = GetWindowOwner(m_hWnd);
    ::ShowWindow(m_hWnd, SW_SHOWNORMAL);
    ::EnableWindow(hWndParent, FALSE);
    MSG msg = { 0 };
    while( ::IsWindow(m_hWnd) && ::GetMessage(&msg, NULL, 0, 0) ) {
        if( msg.message == WM_CLOSE && msg.hwnd == m_hWnd ) {
            nRet = msg.wParam;
            ::EnableWindow(hWndParent, TRUE);
            ::SetFocus(hWndParent);
        }
        if( !CPaintManagerUI::TranslateMessage(&msg) ) {
            ::TranslateMessage(&msg);
            ::DispatchMessage(&msg);
        }
        if( msg.message == WM_QUIT ) break;
    }
    ::EnableWindow(hWndParent, TRUE);
    ::SetFocus(hWndParent);
    if( msg.message == WM_QUIT ) ::PostQuitMessage(msg.wParam);
    return nRet;
}

void CWindowWnd::Close(UINT nRet)
{
    ASSERT(::IsWindow(m_hWnd));
    if( !::IsWindow(m_hWnd) ) return;
    PostMessage(WM_CLOSE, (WPARAM)nRet, 0L);
}

void CWindowWnd::CenterWindow()
{
    ASSERT(::IsWindow(m_hWnd));
    ASSERT((GetWindowStyle(m_hWnd)&WS_CHILD)==0);
    RECT rcDlg = { 0 };
    ::GetWindowRect(m_hWnd, &rcDlg);
    RECT rcArea = { 0 };
    RECT rcCenter = { 0 };
    HWND hWnd=*this;
    HWND hWndParent = ::GetParent(m_hWnd);
    HWND hWndCenter = ::GetWindowOwner(m_hWnd);
    if (hWndCenter!=NULL)
        hWnd=hWndCenter;

    // 处理多显示器模式下屏幕居中
    MONITORINFO oMonitor = {};
    oMonitor.cbSize = sizeof(oMonitor);
    ::GetMonitorInfo(::MonitorFromWindow(hWnd, MONITOR_DEFAULTTONEAREST), &oMonitor);
    rcArea = oMonitor.rcWork;

    if( hWndCenter == NULL )
        rcCenter = rcArea;
    else
        ::GetWindowRect(hWndCenter, &rcCenter);

    int DlgWidth = rcDlg.right - rcDlg.left;
    int DlgHeight = rcDlg.bottom - rcDlg.top;

    // Find dialog's upper left based on rcCenter
    int xLeft = (rcCenter.left + rcCenter.right) / 2 - DlgWidth / 2;
    int yTop = (rcCenter.top + rcCenter.bottom) / 2 - DlgHeight / 2;

    // The dialog is outside the screen, move it inside
    if( xLeft < rcArea.left ) xLeft = rcArea.left;
    else if( xLeft + DlgWidth > rcArea.right ) xLeft = rcArea.right - DlgWidth;
    if( yTop < rcArea.top ) yTop = rcArea.top;
    else if( yTop + DlgHeight > rcArea.bottom ) yTop = rcArea.bottom - DlgHeight;
    ::SetWindowPos(m_hWnd, NULL, xLeft, yTop, -1, -1, SWP_NOSIZE | SWP_NOZORDER | SWP_NOACTIVATE);
}

//从资源设置图标
void CWindowWnd::SetIcon(UINT nRes)
{
    HICON hIcon = (HICON)::LoadImage(CPaintManagerUI::GetInstance(), MAKEINTRESOURCE(nRes), IMAGE_ICON,
        (::GetSystemMetrics(SM_CXICON) + 15) & ~15, (::GetSystemMetrics(SM_CYICON) + 15) & ~15,    // 防止高DPI下图标模糊
        LR_DEFAULTCOLOR);
    ASSERT(hIcon);
    ::SendMessage(m_hWnd, WM_SETICON, (WPARAM) ICON_SMALL, (LPARAM) hIcon);

    hIcon = (HICON)::LoadImage(CPaintManagerUI::GetInstance(), MAKEINTRESOURCE(nRes), IMAGE_ICON,
        (::GetSystemMetrics(SM_CXICON) + 15) & ~15, (::GetSystemMetrics(SM_CYICON) + 15) & ~15,    // 防止高DPI下图标模糊
        LR_DEFAULTCOLOR);
    ASSERT(hIcon);
    ::SendMessage(m_hWnd, WM_SETICON, (WPARAM) ICON_BIG, (LPARAM) hIcon);
}

bool CWindowWnd::RegisterWindowClass()
{
    WNDCLASS wc = { 0 };
    wc.style = GetClassStyle();
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hIcon = NULL;
    wc.lpfnWndProc = CWindowWnd::__WndProc;
    wc.hInstance = CPaintManagerUI::GetInstance();
    wc.hCursor = ::LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = NULL;
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = GetWindowClassName();
    ATOM ret = ::RegisterClass(&wc);
    ASSERT(ret!=NULL || ::GetLastError()==ERROR_CLASS_ALREADY_EXISTS);
    return ret != NULL || ::GetLastError() == ERROR_CLASS_ALREADY_EXISTS;
}

//这里应该是创建一个控件类，子类化过的
bool CWindowWnd::RegisterSuperclass()
{
    // Get the class information from an existing
    // window so we can subclass it later on...
    WNDCLASSEX wc = { 0 };
    wc.cbSize = sizeof(WNDCLASSEX);
    if( !::GetClassInfoEx(NULL, GetSuperClassName(), &wc) ) {
        if( !::GetClassInfoEx(CPaintManagerUI::GetInstance(), GetSuperClassName(), &wc) ) {
            ASSERT(!"Unable to locate window class");
            return NULL;
        }
    }
    m_OldWndProc = wc.lpfnWndProc;
    wc.lpfnWndProc = CWindowWnd::__ControlProc;
    wc.hInstance = CPaintManagerUI::GetInstance();
    wc.lpszClassName = GetWindowClassName();
    ATOM ret = ::RegisterClassEx(&wc);
    ASSERT(ret!=NULL || ::GetLastError()==ERROR_CLASS_ALREADY_EXISTS);
    return ret != NULL || ::GetLastError() == ERROR_CLASS_ALREADY_EXISTS;
}

//默认的消息处理函数 注册窗口时使用过
LRESULT CALLBACK CWindowWnd::__WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    CWindowWnd* pThis = NULL;
    if( uMsg == WM_NCCREATE ) {
        //首次创建窗口时调用
        LPCREATESTRUCT lpcs = reinterpret_cast<LPCREATESTRUCT>(lParam);
        pThis = static_cast<CWindowWnd*>(lpcs->lpCreateParams);
        pThis->m_hWnd = hWnd;
        ::SetWindowLongPtr(hWnd, GWLP_USERDATA, reinterpret_cast<LPARAM>(pThis));
    } 
    else {
        pThis = reinterpret_cast<CWindowWnd*>(::GetWindowLongPtr(hWnd, GWLP_USERDATA));
        //销毁窗口时调用
        if( uMsg == WM_NCDESTROY && pThis != NULL ) {
            //把消息传递到上一层
            LRESULT lRes = ::CallWindowProc(pThis->m_OldWndProc, hWnd, uMsg, wParam, lParam);
            ::SetWindowLongPtr(pThis->m_hWnd, GWLP_USERDATA, 0L);
            //如果已经子类化了，则恢复
            if( pThis->m_bSubclassed ) pThis->Unsubclass();
            pThis->m_hWnd = NULL;
            //调用OnFinalMessage OnFinalMessage一般做最后的处理
            pThis->OnFinalMessage(hWnd);
            return lRes;
        }
    }
    if( pThis != NULL ) {
        //调用HandleMessage来处理消息
        return pThis->HandleMessage(uMsg, wParam, lParam);
    } 
    else {
        return ::DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
}

//控件的消息处理函数
LRESULT CALLBACK CWindowWnd::__ControlProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    CWindowWnd* pThis = NULL;
    if( uMsg == WM_NCCREATE ) {
        LPCREATESTRUCT lpcs = reinterpret_cast<LPCREATESTRUCT>(lParam);
        pThis = static_cast<CWindowWnd*>(lpcs->lpCreateParams);
        ::SetProp(hWnd, _T("WndX"), (HANDLE) pThis);
        pThis->m_hWnd = hWnd;
    } 
    else {
        pThis = reinterpret_cast<CWindowWnd*>(::GetProp(hWnd, _T("WndX")));
        if( uMsg == WM_NCDESTROY && pThis != NULL ) {
            LRESULT lRes = ::CallWindowProc(pThis->m_OldWndProc, hWnd, uMsg, wParam, lParam);
            if( pThis->m_bSubclassed ) pThis->Unsubclass();
            ::SetProp(hWnd, _T("WndX"), NULL);
            pThis->m_hWnd = NULL;
            pThis->OnFinalMessage(hWnd);
            return lRes;
        }
    }
    if( pThis != NULL ) {
        return pThis->HandleMessage(uMsg, wParam, lParam);
    } 
    else {
        return ::DefWindowProc(hWnd, uMsg, wParam, lParam);
    }
}

LRESULT CWindowWnd::SendMessage(UINT uMsg, WPARAM wParam /*= 0*/, LPARAM lParam /*= 0*/)
{
    ASSERT(::IsWindow(m_hWnd));
    return ::SendMessage(m_hWnd, uMsg, wParam, lParam);
} 

LRESULT CWindowWnd::PostMessage(UINT uMsg, WPARAM wParam /*= 0*/, LPARAM lParam /*= 0*/)
{
    ASSERT(::IsWindow(m_hWnd));
    return ::PostMessage(m_hWnd, uMsg, wParam, lParam);
}

void CWindowWnd::ResizeClient(int cx /*= -1*/, int cy /*= -1*/)
{
    ASSERT(::IsWindow(m_hWnd));
    RECT rc = { 0 };
    if( !::GetClientRect(m_hWnd, &rc) ) return;
    if( cx != -1 ) rc.right = cx;
    if( cy != -1 ) rc.bottom = cy;
    if( !::AdjustWindowRectEx(&rc, GetWindowStyle(m_hWnd), (!(GetWindowStyle(m_hWnd) & WS_CHILD) && (::GetMenu(m_hWnd) != NULL)), GetWindowExStyle(m_hWnd)) ) return;
    ::SetWindowPos(m_hWnd, NULL, 0, 0, rc.right - rc.left, rc.bottom - rc.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
}

//虚函数 用于在子类里重写此函数接管消息
LRESULT CWindowWnd::HandleMessage(UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    return ::CallWindowProc(m_OldWndProc, m_hWnd, uMsg, wParam, lParam);
}

void CWindowWnd::OnFinalMessage(HWND /*hWnd*/)
{
}

//////////////////////////////////////////////////////////////////////////

流程：

调用Create创建一个窗口，使用RegisterSuperclass或RegisterWindowClass注册类，调用CreateWindowEx创建窗口返回句柄。
RegisterSuperclass使用CWindowWnd::__ControlProc作为窗口消息处理函数，
RegisterWindowClass使用CWindowWnd::__WndProc作为消息处理函数。
两个消息处理函数除了WM_NCDESTROY以外其他消息都通过HandleMessage来处理，所以继承类中只要重载HandleMessage就可以处理大部分消息了。