Qt based Application Extension
![]() |
Home |
Qt based Application Extension
This examples shows how to use the QWinWidget and QMfcApp classes to implement a Qt based user interface in a plugin DLL.
The plugin implements and exports a C function showDialog that can be called by any Windows application to display a modal Qt dialog. Before a Qt based user interface can be created a QApplication object must exist, and the calling application's event loop and the Qt event loop must run together.
/**************************************************************************** ** ** Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of a Qt Solutions component. ** ** Commercial Usage ** Licensees holding valid Qt Commercial licenses may use this file in ** accordance with the Qt Solutions Commercial License Agreement provided ** with the Software or, alternatively, in accordance with the terms ** contained in a written agreement between you and Nokia. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain ** additional rights. These rights are described in the Nokia Qt LGPL ** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this ** package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** Please note Third Party Software included with Qt Solutions may impose ** additional restrictions and it is the user's responsibility to ensure ** that they have met the licensing requirements of the GPL, LGPL, or Qt ** Solutions Commercial license and the relevant license of the Third ** Party Software they are using. ** ** If you are unsure which license is appropriate for your use, please ** contact Nokia at qt-info@nokia.com. ** ****************************************************************************/ #include <qmfcapp.h> #include <qwinwidget.h> #include <QtGui/QMessageBox> #include <windows.h> BOOL WINAPI DllMain( HINSTANCE hInstance, DWORD dwReason, LPVOID /*lpvReserved*/ ) { static bool ownApplication = FALSE; if ( dwReason == DLL_PROCESS_ATTACH ) ownApplication = QMfcApp::pluginInstance( hInstance ); if ( dwReason == DLL_PROCESS_DETACH && ownApplication ) delete qApp; return TRUE; }
The DLL entry point function DllMain uses the QMfcApp::pluginInstance function to make sure that exactly one instance ofQApplication exists in the process, and that the DLL owning that instance stays loaded in memory.
extern "C" __declspec(dllexport) bool showDialog( HWND parent ) { QWinWidget win( parent ); win.showCentered(); QMessageBox::about( &win, "About QtMfc", "QtMfc Version 1.0\nCopyright (C) 2003" ); return TRUE; }
The C function showDialog is exported from the DLL and uses the QWinWidget class to provide proper stacking and modality between the native Win32 window and the QMessageBox.
http://doc.qt.digia.com/solutions/4/qtwinmigrate/winmigrate-qt-dll-example.html
Copyright © 2009 Nokia Corporation and/or its subsidiary(-ies) | Trademarks |
Qt Solutions
|