自学教程：C++ wxLogLastError函数代码示例

// The wxWindow destructor will take care of deleting the submenus.wxMenu::~wxMenu(){    // we should free Windows resources only if Windows doesn't do it for us    // which happens if we're attached to a menubar or a submenu of another    // menu    if ( m_hMenu && !IsAttached() && !GetParent() )    {        if ( !::DestroyMenu(GetHmenu()) )        {            wxLogLastError(wxT("DestroyMenu"));        }    }#if wxUSE_ACCEL    // delete accels    WX_CLEAR_ARRAY(m_accels);#endif // wxUSE_ACCEL    delete m_radioData;}

void wxMenuItem::Enable(bool enable){    if ( m_isEnabled == enable )        return;    if ( m_parentMenu )    {        long rc = EnableMenuItem(GetHMenuOf(m_parentMenu),                                 GetMSWId(),                                 MF_BYCOMMAND |                                 (enable ? MF_ENABLED : MF_GRAYED));        if ( rc == -1 )        {            wxLogLastError(wxT("EnableMenuItem"));        }    }    wxMenuItemBase::Enable(enable);}

// This is used by wxProcess::Activate().externbool wxMSWActivatePID(long pid){    wxFindByPidParams params;    params.pid = (DWORD)pid;    if ( ::EnumWindows(wxEnumFindByPidProc, (LPARAM)&params) != 0 )    {        // No windows corresponding to this PID were found.        return false;    }    if ( !::BringWindowToTop(params.hwnd) )    {        wxLogLastError(wxS("BringWindowToTop"));        return false;    }    return true;}

bool wxSpinCtrl::Reparent(wxWindowBase *newParent){    // Reparenting both the updown control and its buddy does not seem to work:    // they continue to be connected somehow, but visually there is no feedback    // on the buddy edit control. To avoid this problem, we reparent the buddy    // window normally, but we recreate the updown control and reassign its    // buddy.    if ( !wxWindowBase::Reparent(newParent) )        return false;    newParent->GetChildren().DeleteObject(this);    // preserve the old values    const wxSize size = GetSize();    int value = GetValue();    const wxRect btnRect = wxRectFromRECT(wxGetWindowRect(GetHwnd()));    // destroy the old spin button    UnsubclassWin();    if ( !::DestroyWindow(GetHwnd()) )    {        wxLogLastError(wxT("DestroyWindow"));    }    // create and initialize the new one    if ( !wxSpinButton::Create(GetParent(), GetId(),                               btnRect.GetPosition(), btnRect.GetSize(),                               GetWindowStyle(), GetName()) )        return false;    SetValue(value);    SetRange(m_min, m_max);    SetInitialSize(size);    // associate it with the buddy control again    ::SetParent(GetBuddyHwnd(), GetHwndOf(GetParent()));    (void)::SendMessage(GetHwnd(), UDM_SETBUDDY, (WPARAM)GetBuddyHwnd(), 0);    return true;}

wxGLContext::wxGLContext(wxGLCanvas *win, const wxGLContext* other){    if ( s_wglContextAttribs[0] == 0 ) // create legacy context    {        m_glContext = wglCreateContext(win->GetHDC());        wxCHECK_RET( m_glContext, wxT("Couldn't create OpenGL context") );    }    else // create a context using attributes    {        // We need to create a temporary context to get the        // wglCreateContextAttribsARB function        HGLRC tempContext = wglCreateContext(win->GetHDC());        wxCHECK_RET( tempContext, wxT("Couldn't create OpenGL context") );        wglMakeCurrent(win->GetHDC(), tempContext);        PFNWGLCREATECONTEXTATTRIBSARBPROC wglCreateContextAttribsARB            = (PFNWGLCREATECONTEXTATTRIBSARBPROC)            wglGetProcAddress("wglCreateContextAttribsARB");        wglMakeCurrent(win->GetHDC(), NULL);        wglDeleteContext(tempContext);        if ( !wglCreateContextAttribsARB )        {            wxLogError(_("Core OpenGL profile is not supported by the OpenGL driver."));            return;        }        m_glContext = wglCreateContextAttribsARB(            win->GetHDC(), 0, s_wglContextAttribs);        wxCHECK_RET( m_glContext,                     wxT("Couldn't create core profile OpenGL context") );    }    if ( other )    {        if ( !wglShareLists(other->m_glContext, m_glContext) )        {            wxLogLastError(wxT("wglShareLists"));        }    }}

wxMenu* wxMenuBar::Replace(  size_t                             nPos, wxMenu*                            pMenu, const wxString&                    rTitle){    SHORT                            nId;    wxString                         sTitle = wxPMTextToLabel(rTitle);    wxMenu*                          pMenuOld = wxMenuBarBase::Replace( nPos                                                                       ,pMenu                                                                       ,sTitle                                                                      );    nId = SHORT1FROMMR(::WinSendMsg((HWND)m_hMenu, MM_ITEMIDFROMPOSITION, MPFROMSHORT(nPos), (MPARAM)0));    if (nId == MIT_ERROR)    {        wxLogLastError(wxT("LogLastError"));        return NULL;    }    if (!pMenuOld)        return NULL;    m_titles[nPos] = sTitle;    if (IsAttached())    {        ::WinSendMsg((HWND)m_hMenu, MM_REMOVEITEM, MPFROM2SHORT(nId, TRUE), (MPARAM)0);        ::WinSendMsg((HWND)m_hMenu, MM_INSERTITEM, (MPARAM)&pMenu->m_vMenuData, (MPARAM)sTitle.wx_str());#if wxUSE_ACCEL        if (pMenuOld->HasAccels() || pMenu->HasAccels())        {            //            // Need to rebuild accell table            //            RebuildAccelTable();        }#endif // wxUSE_ACCEL        Refresh();    }    return pMenuOld;} // end of wxMenuBar::Replace

void wxMemoryDC::SelectObject(const wxBitmap& bitmap){    // select old bitmap out of the device context    if ( m_oldBitmap )    {        ::SelectObject(GetHdc(), (HBITMAP) m_oldBitmap);        if ( m_selectedBitmap.Ok() )        {#ifdef __WXDEBUG__            m_selectedBitmap.SetSelectedInto(NULL);#endif            m_selectedBitmap = wxNullBitmap;        }    }    // check for whether the bitmap is already selected into a device context    wxASSERT_MSG( !bitmap.GetSelectedInto() ||                  (bitmap.GetSelectedInto() == this),                  wxT("Bitmap is selected in another wxMemoryDC, delete the first wxMemoryDC or use SelectObject(NULL)") );    m_selectedBitmap = bitmap;    WXHBITMAP hBmp = m_selectedBitmap.GetHBITMAP();    if ( !hBmp )        return;#ifdef __WXDEBUG__    m_selectedBitmap.SetSelectedInto(this);#endif    hBmp = (WXHBITMAP)::SelectObject(GetHdc(), (HBITMAP)hBmp);    if ( !hBmp )    {        wxLogLastError(wxT("SelectObject(memDC, bitmap)"));        wxFAIL_MSG(wxT("Couldn't select a bitmap into wxMemoryDC"));    }    else if ( !m_oldBitmap )    {        m_oldBitmap = hBmp;    }}

void wxMenuItem::Enable(bool enable){    if ( m_isEnabled == enable )        return;    const int itemPos = MSGetMenuItemPos();    if ( itemPos != -1 )    {        long rc = EnableMenuItem(GetHMenuOf(m_parentMenu),                                 itemPos,                                 MF_BYPOSITION |                                 (enable ? MF_ENABLED : MF_GRAYED));        if ( rc == -1 )        {            wxLogLastError(wxT("EnableMenuItem"));        }    }    wxMenuItemBase::Enable(enable);}

WXHBRUSH wxNotebook::MSWGetBgBrushForChild(WXHDC hDC, wxWindow *child){    if ( m_hbrBackground )    {        // before drawing with the background brush, we need to position it        // correctly        RECT rc;        ::GetWindowRect(GetHwndOf(child), &rc);        ::MapWindowPoints(NULL, GetHwnd(), (POINT *)&rc, 1);        if ( !::SetBrushOrgEx((HDC)hDC, -rc.left, -rc.top, NULL) )        {            wxLogLastError(wxT("SetBrushOrgEx(notebook bg brush)"));        }        return m_hbrBackground;    }    return wxNotebookBase::MSWGetBgBrushForChild(hDC, child);}

//// The wxWindow destructor will take care of deleting the submenus.//wxMenu::~wxMenu(){    //    // We should free PM resources only if PM doesn't do it for us    // which happens if we're attached to a menubar or a submenu of another    // menu    if (!IsAttached() && !GetParent())    {        if (!::WinDestroyWindow((HWND)GetHmenu()) )        {            wxLogLastError(wxT("WinDestroyWindow"));        }    }#if wxUSE_ACCEL    //    // Delete accels    //    WX_CLEAR_ARRAY(m_vAccels);#endif // wxUSE_ACCEL} // end of wxMenu::~wxMenu

wxString wxChoice::GetString(unsigned int n) const{    int len = (int)::SendMessage(GetHwnd(), CB_GETLBTEXTLEN, n, 0);    wxString str;    if ( len != CB_ERR && len > 0 )    {        if ( ::SendMessage               (                GetHwnd(),                CB_GETLBTEXT,                n,                (LPARAM)(wxChar *)wxStringBuffer(str, len)               ) == CB_ERR )        {            wxLogLastError(wxT("SendMessage(CB_GETLBTEXT)"));        }    }    return str;}

wxSemaError wxSemaphoreInternal::Post(){#if !defined(_WIN32_WCE) || (_WIN32_WCE >= 300)    if ( !::ReleaseSemaphore(m_semaphore, 1, NULL /* ptr to previous count */) )    {        if ( GetLastError() == ERROR_TOO_MANY_POSTS )        {            return wxSEMA_OVERFLOW;        }        else        {            wxLogLastError(wxT("ReleaseSemaphore"));            return wxSEMA_MISC_ERROR;        }    }    return wxSEMA_NO_ERROR;#else    return wxSEMA_MISC_ERROR;#endif}

bool gcTaskBarIcon::RemoveIcon(){#ifdef WIN32	if (!m_iconAdded)		return false;	m_iconAdded = false;	NotifyIconData notifyData(GetHwndOf(m_win));	bool ok = wxShellNotifyIcon(NIM_DELETE, &notifyData) != 0;	if ( !ok )	{		wxLogLastError(wxT("wxShellNotifyIcon(NIM_DELETE)"));	}	return ok;#else	return false;#endif}

bool wxMSWEventLoopBase::GetNextMessage(WXMSG* msg){    const BOOL rc = ::GetMessage(msg, NULL, 0, 0);    if ( rc == 0 )    {        // got WM_QUIT        return false;    }    if ( rc == -1 )    {        // should never happen, but let's test for it nevertheless        wxLogLastError(wxT("GetMessage"));        // still break from the loop        return false;    }    return true;}

void wxApp::WakeUpIdle(){    //    // Send the top window a dummy message so idle handler processing will    // start up again.  Doing it this way ensures that the idle handler    // wakes up in the right thread (see also wxWakeUpMainThread() which does    // the same for the main app thread only)    //    wxWindow*                       pTopWindow = wxTheApp->GetTopWindow();    if (pTopWindow)    {        if ( !::WinPostMsg(GetHwndOf(pTopWindow), WM_NULL, (MPARAM)0, (MPARAM)0))        {            //            // Should never happen            //            wxLogLastError(wxT("PostMessage(WM_NULL)"));        }    }} // end of wxWakeUpIdle

//// NB: we don't support owner drawn top level items for now, if we do these//     functions would have to be changed to use wxMenuItem as well//void wxMenuBar::EnableTop(  size_t                            nPos, bool                              bEnable){    wxCHECK_RET(IsAttached(), wxT("doesn't work with unattached menubars"));    USHORT                          uFlag = 0;    SHORT                           nId;    if(!bEnable)       uFlag = MIA_DISABLED;    nId = SHORT1FROMMR(::WinSendMsg((HWND)m_hMenu, MM_ITEMIDFROMPOSITION, MPFROMSHORT(nPos), (MPARAM)0));    if (nId == MIT_ERROR)    {        wxLogLastError(wxT("LogLastError"));        return;    }    ::WinSendMsg((HWND)m_hMenu, MM_SETITEMATTR, MPFROM2SHORT(nId, TRUE), MPFROM2SHORT(MIA_DISABLED, uFlag));    Refresh();} // end of wxMenuBar::EnableTop

bool wxDIB::Create(HBITMAP hbmp){    // this bitmap could already be a DIB section in which case we don't need    // to convert it to DIB    DIBSECTION ds;    if ( GetDIBSection(hbmp, &ds) )    {        m_handle = hbmp;        // wxBitmap will free it, not we        m_ownsHandle = false;        // copy all the bitmap parameters too as we have them now anyhow        m_width = ds.dsBm.bmWidth;        m_height = ds.dsBm.bmHeight;        m_depth = ds.dsBm.bmBitsPixel;        m_data = ds.dsBm.bmBits;    }    else // no, it's a DDB -- convert it to DIB    {        // prepare all the info we need        BITMAP bm;        if ( !::GetObject(hbmp, sizeof(bm), &bm) )        {            wxLogLastError(wxT("GetObject(bitmap)"));            return false;        }        int d = bm.bmBitsPixel;        if ( d <= 0 )            d = wxDisplayDepth();        if ( !Create(bm.bmWidth, bm.bmHeight, d) || !CopyFromDDB(hbmp) )            return false;    }    return true;}

bool wxTextMeasure::DoGetPartialTextExtents(const wxString& text,                                            wxArrayInt& widths,                                            double scaleX){    if ( !m_hdc )        return wxTextMeasureBase::DoGetPartialTextExtents(text, widths, scaleX);    static int maxLenText = -1;    static int maxWidth = -1;    if (maxLenText == -1)    {        // Win9x and WinNT+ have different limits        int version = wxGetOsVersion();        maxLenText = version == wxOS_WINDOWS_NT ? 65535 : 8192;        maxWidth =   version == wxOS_WINDOWS_NT ? INT_MAX : 32767;    }    int len = text.length();    if ( len > maxLenText )        len = maxLenText;    int fit = 0;    SIZE sz = {0,0};    if ( !::GetTextExtentExPoint(m_hdc,                                 text.t_str(), // string to check                                 len,                                 maxWidth,                                 &fit,         // [out] count of chars                                               // that will fit                                 &widths[0],   // array to fill                                 &sz) )    {        wxLogLastError(wxT("GetTextExtentExPoint"));        return false;    }    return true;}

bool wxTextMeasure::DoGetPartialTextExtents(const wxString& text,                                            wxArrayInt& widths,                                            double scaleX){    if ( !m_layout )        return wxTextMeasureBase::DoGetPartialTextExtents(text, widths, scaleX);    // Set layout's text    const wxCharBuffer dataUTF8 = wxGTK_CONV_FONT(text, GetFont());    if ( !dataUTF8 )    {        // hardly ideal, but what else can we do if conversion failed?        wxLogLastError(wxT("GetPartialTextExtents"));        return false;    }    pango_layout_set_text(m_layout, dataUTF8, -1);    // Calculate the position of each character based on the widths of    // the previous characters    // Code borrowed from Scintilla's PlatGTK    PangoLayoutIter *iter = pango_layout_get_iter(m_layout);    PangoRectangle pos;    pango_layout_iter_get_cluster_extents(iter, NULL, &pos);    size_t i = 0;    while (pango_layout_iter_next_cluster(iter))    {        pango_layout_iter_get_cluster_extents(iter, NULL, &pos);        int position = PANGO_PIXELS(pos.x);        widths[i++] = position;    }    const size_t len = text.length();    while (i < len)        widths[i++] = PANGO_PIXELS(pos.x + pos.width);    pango_layout_iter_free(iter);    return true;}

// End dragbool wxDragImage::EndDrag(){    wxASSERT_MSG( (m_hImageList != 0), wxT("Image list must not be null in EndDrag."));    ImageList_EndDrag();    if ( !::ReleaseCapture() )    {        wxLogLastError(wxT("ReleaseCapture"));    }#if wxUSE_SIMPLER_DRAGIMAGE    if (m_cursor.Ok() && m_oldCursor.Ok())        m_window->SetCursor(m_oldCursor);#else    ::ShowCursor(TRUE);#endif    m_window = NULL;    return true;}

bool wxDoSetEnv(const wxString& var, const wxChar *value){#ifdef __WXWINCE__    // no environment variables under CE    wxUnusedVar(var);    wxUnusedVar(value);    return false;#else // !__WXWINCE__    // update the CRT environment if possible as people expect getenv() to also    // work and it is not affected by Win32 SetEnvironmentVariable() call (OTOH    // the CRT does use Win32 call to update the process environment block so    // there is no need to call it)    //    // TODO: add checks for the other compilers (and update wxSetEnv()    //       documentation in interface/wx/utils.h accordingly)#if defined(__VISUALC__) || defined(__MINGW32__)    // notice that Microsoft _putenv() has different semantics from POSIX    // function with almost the same name: in particular it makes a copy of the    // string instead of using it as part of environment so we can safely call    // it here without going through all the troubles with wxSetEnvModule as in    // src/unix/utilsunx.cpp    wxString envstr = var;    envstr += '=';    if ( value )        envstr += value;    if ( _tputenv(envstr.t_str()) != 0 )        return false;#else // other compiler    if ( !::SetEnvironmentVariable(var.t_str(), value) )    {        wxLogLastError(wxT("SetEnvironmentVariable"));        return false;    }#endif // compiler    return true;#endif // __WXWINCE__/!__WXWINCE__}

void wxStatusBar95::SetStatusText(const wxString& strText, int nField){    wxCHECK_RET( (nField >= 0) && (nField < m_nFields),                 _T("invalid statusbar field index") );    if ( strText == GetStatusText(nField) )    {       // don't call StatusBar_SetText() to avoid flicker       return;    }    // Get field style, if any    int style;    if (m_statusStyles)    {        switch(m_statusStyles[nField])        {        case wxSB_RAISED:            style = SBT_POPOUT;            break;        case wxSB_FLAT:            style = SBT_NOBORDERS;            break;        case wxSB_NORMAL:        default:            style = 0;            break;        }    }    else        style = 0;    // Pass both field number and style. MSDN library doesn't mention    // that nField and style have to be 'ORed'    if ( !StatusBar_SetText(GetHwnd(), nField | style, strText) )    {        wxLogLastError(wxT("StatusBar_SetText"));    }}

void wxTopLevelWindowMSW::DoGetPosition(int *x, int *y) const{    if ( IsIconized() )    {        WINDOWPLACEMENT wp;        wp.length = sizeof(WINDOWPLACEMENT);        if ( ::GetWindowPlacement(GetHwnd(), &wp) )        {            RECT& rc = wp.rcNormalPosition;            // the position returned by GetWindowPlacement() is in workspace            // coordinates except for windows with WS_EX_TOOLWINDOW style            if ( !HasFlag(wxFRAME_TOOL_WINDOW) )            {                // we must use the correct display for the translation as the                // task bar might be shown on one display but not the other one                int n = wxDisplay::GetFromWindow(this);                wxDisplay dpy(n == wxNOT_FOUND ? 0 : n);                const wxPoint ptOfs = dpy.GetClientArea().GetPosition() -                                      dpy.GetGeometry().GetPosition();                rc.left += ptOfs.x;                rc.top += ptOfs.y;            }            if ( x )                *x = rc.left;            if ( y )                *y = rc.top;            return;        }        wxLogLastError(wxT("GetWindowPlacement"));    }    //else: normal case    wxTopLevelWindowBase::DoGetPosition(x, y);}

static void InsertWindowMenu(wxWindow *win, WXHMENU menu, HMENU subMenu){    // Try to insert Window menu in front of Help, otherwise append it.    HMENU hmenu = (HMENU)menu;    if (subMenu)    {        int N = GetMenuItemCount(hmenu);        bool success = false;        for ( int i = 0; i < N; i++ )        {            wxChar buf[256];            int chars = GetMenuString(hmenu, i, buf, WXSIZEOF(buf), MF_BYPOSITION);            if ( chars == 0 )            {                wxLogLastError(wxT("GetMenuString"));                continue;            }            if ( wxStripMenuCodes(wxString(buf)).IsSameAs(_("Help")) )            {                success = true;                ::InsertMenu(hmenu, i, MF_BYPOSITION | MF_POPUP | MF_STRING,                             (UINT)subMenu, _("&Window"));                break;            }        }        if ( !success )        {            ::AppendMenu(hmenu, MF_POPUP, (UINT)subMenu, _("&Window"));        }    }    MDISetMenu(win, hmenu, subMenu);}

HBITMAP wxDIB::CreateDDB(HDC hdc) const{    wxCHECK_MSG( m_handle, 0, wxT("wxDIB::CreateDDB(): invalid object") );    DIBSECTION ds;    if ( !GetDIBSection(m_handle, &ds) )    {        wxLogLastError(wxT("GetObject(hDIB)"));        return 0;    }    // how many colours are we going to have in the palette?    DWORD biClrUsed = ds.dsBmih.biClrUsed;    if ( !biClrUsed )    {        // biClrUsed field might not be set        biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount);    }    if ( !biClrUsed )    {        return ConvertToBitmap((BITMAPINFO *)&ds.dsBmih, hdc, ds.dsBm.bmBits);    }    else    {        // fake a BITMAPINFO w/o bits, just the palette info        wxCharBuffer bmi(sizeof(BITMAPINFO) + (biClrUsed - 1)*sizeof(RGBQUAD));        BITMAPINFO *pBmi = (BITMAPINFO *)bmi.data();        MemoryHDC hDC;        // get the colour table        SelectInHDC sDC(hDC, m_handle);        ::GetDIBColorTable(hDC, 0, biClrUsed, pBmi->bmiColors);        memcpy(&pBmi->bmiHeader, &ds.dsBmih, ds.dsBmih.biSize);        return ConvertToBitmap(pBmi, hdc, ds.dsBm.bmBits);    }}

// Gets an HDC for the specified printer configurationWXHDC WXDLLEXPORT wxGetPrinterDC(const wxPrintData& printDataConst){#if wxUSE_PS_PRINTING    // TODO    wxUnusedVar(printDataConst);    return 0;#else // native Windows printing    wxWindowsPrintNativeData *data =        (wxWindowsPrintNativeData *) printDataConst.GetNativeData();    data->TransferFrom( printDataConst );    wxString deviceName = printDataConst.GetPrinterName();    if ( deviceName.empty() )    {        // Retrieve the default device name        wxString portName;        if ( !wxGetDefaultDeviceName(deviceName, portName) )        {            return 0; // Could not get default device name        }    }    HGLOBAL hDevMode = (HGLOBAL)(DWORD) data->GetDevMode();    DEVMODE *lpDevMode = hDevMode ? (DEVMODE *)::GlobalLock(hDevMode) : NULL;    HDC hDC = ::CreateDC(NULL, deviceName, NULL, lpDevMode);    if ( !hDC )        wxLogLastError(_T("CreateDC(printer)"));    if ( lpDevMode )        ::GlobalUnlock(hDevMode);    return (WXHDC) hDC;#endif // PostScript/Windows printing}

bool wxBitmapDataObject2::SetData(size_t WXUNUSED(len), const void *pBuf){    HBITMAP hbmp = *(HBITMAP *)pBuf;    BITMAP bmp;    if ( !GetObject(hbmp, sizeof(BITMAP), &bmp) )    {        wxLogLastError(wxT("GetObject(HBITMAP)"));    }    wxBitmap bitmap(bmp.bmWidth, bmp.bmHeight, bmp.bmPlanes);    bitmap.SetHBITMAP((WXHBITMAP)hbmp);    if ( !bitmap.IsOk() ) {        wxFAIL_MSG(wxT("pasting/dropping invalid bitmap"));        return false;    }    SetBitmap(bitmap);    return true;}

void wxMenu::Init(){    m_doBreak = false;    m_startRadioGroup = -1;    // create the menu    m_macMenuId = s_macNextMenuId++;    m_hMenu = UMANewMenu(m_macMenuId, m_title, wxFont::GetDefaultEncoding() );    if ( !m_hMenu )    {        wxLogLastError(wxT("UMANewMenu failed"));    }    wxAssociateMenuWithMacMenu( (MenuRef)m_hMenu , this ) ;    // if we have a title, insert it in the beginning of the menu    if ( !m_title.empty() )    {        Append(idMenuTitle, m_title) ;        AppendSeparator() ;    }}