qmessagebox.h File Reference

#include <QtGui/qdialog.h>

Go to the source code of this file.

Classes
class	QMessageBox
	The QMessageBox class provides a modal dialog for informing the user or for asking the user a question and receiving an answer. More...

Macros
#define	QT_REQUIRE_VERSION(argc, argv, str)

Macro Definition Documentation

QT_REQUIRE_VERSION

#define QT_REQUIRE_VERSION	(		argc,
			argv,
			str
	)

Value:

{ QString s = QString::fromLatin1(str);\
QString sq = QString::fromLatin1(qVersion()); \
if ((sq.section(QChar::fromLatin1('.'),0,0).toInt()<<16)+\
(sq.section(QChar::fromLatin1('.'),1,1).toInt()<<8)+\
sq.section(QChar::fromLatin1('.'),2,2).toInt()<(s.section(QChar::fromLatin1('.'),0,0).toInt()<<16)+\
(s.section(QChar::fromLatin1('.'),1,1).toInt()<<8)+\
s.section(QChar::fromLatin1('.'),2,2).toInt()) { \
if (!qApp){ \
    new QApplication(argc,argv); \
} \
QString s = QApplication::tr("Executable '%1' requires Qt "\
 "%2, found Qt %3.").arg(qAppName()).arg(QString::fromLatin1(\
str)).arg(QString::fromLatin1(qVersion())); QMessageBox::critical(0, QApplication::tr(\
"Incompatible Qt Library Error"), s, QMessageBox::Abort, 0); qFatal("%s", s.toLatin1().data()); }}

This macro can be used to ensure that the application is run against a recent enough version of Qt. This is especially useful if your application depends on a specific bug fix introduced in a bug-fix release (e.g., 4.0.2).

The argc and argv parameters are the main() function's argc and argv parameters. The version parameter is a string literal that specifies which version of Qt the application requires (e.g., "4.0.2").

Example:

#include <QApplication>
#include <QMessageBox>

int main(int argc, char *argv[])
{
    QT_REQUIRE_VERSION(argc, argv, "4.0.2")

    QApplication app(argc, argv);
    ...
    return app.exec();
}

Definition at line 344 of file qmessagebox.h.