and it behaves OK. For some reason the window must be deleted first.
Just a note for future readers.
EDIT: ...and a different approach for those who want a real process-restart: You can declare a myApp::Restart() method in your subclass of QApplication. The following version works OK on both MS-Windows & MacOS:
// Restart Application
void myApp::Restart(bool Abort)
{
// Spawn a new instance of myApplication:
QProcess proc;
#ifdef Q_OS_WIN
proc.start(this->applicationFilePath());
#endif
#ifdef Q_OS_MAC
// In Mac OS the full path of aplication binary is:
// <base-path>/myApp.app/Contents/MacOS/myApp
QStringList args;
args << (this->applicationDirPath() + "/../../../myApp.app");
proc.start("open", args);
#endif
// Terminate current instance:
if (Abort) // Abort Application process (exit immediattely)
::exit(0);
else
this->exit(0); // Exit gracefully by terminating the myApp instance
}
int main(int argc, char *argv[])
{
int currentExitCode = 0;
do {
QApplication a(argc, argv);
MainWindow w;
w.show();
currentExitCode = a.exec();
} while( currentExitCode == MainWindow::EXIT_CODE_REBOOT );
return currentExitCode;
}
mainwindow.h
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
static int const EXIT_CODE_REBOOT;//THIS IS THE IMPORTANT THING TO ADD TO YOUR CODE
~MainWindow();
private slots:
void slotReboot();//AND THIS ALSO
//ALL THE OTHER VARIABLES
}
The slotReboot() is the slot that will receive the signal of the QAction I'm going to show in the mainwindow.cpp
mainwindow.cpp
First initialize EXIT_CODE_REBOOT :
int const MainWindow::EXIT_CODE_REBOOT = -123456789;
and declare a QAction pointer:
QAction* actionReboot;
then in the MainWindow constructor:
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
actionReboot = new QAction( this );
actionReboot->setText( tr("Restart") );
actionReboot->setStatusTip( tr("Restarts the application") );
connect( actionReboot, SIGNAL (triggered()),this, SLOT (slotReboot()));
}
And finally you need to send the signal (in the part of your code you need), in this way:
int main(int argc, char * argv[])
{
int result = 0;
do
{
QCoreApplication coreapp(argc, argv);
MyClass myObj;
result = coreapp.exec();
} while( result == 1337 );
return result;
}
This slight variation on Rubenvb's idea works with PyQt. clearSettings is the method that triggers the restart.
class GuiMain
#Most of implementation missing
def clearSettings(self):
#Clearing the settings missing
QApplication.exit(GuiMain.restart_code)
restart_code = 1000
@staticmethod
def application_main():
"""
The application's main function.
Create application and main window and run them.
"""
while True:
app = QApplication(sys.argv)
window = GuiMain()
window.show()
ret = app.exec_()
if ret != GuiMain.restart_code:
break
del window
del app
I'm taking the other answers solutions, but better. No need for pointers, but there is a need for a ; after the while statement of a do { ... } while( ... ); construct.
int main(int argc, char *argv[])
{
const int RESTART_CODE = 1000;
do
{
QApplication app(argc, argv);
MainWindow main_window(app);
} while( app.exec() == RESTART_CODE);
return return_from_event_loop_code;
}
I just used the method described above and I noticed that my application crashes on restart. ...then I switched the following lines of code:
to:
and it behaves OK. For some reason the window must be deleted first. Just a note for future readers.
EDIT: ...and a different approach for those who want a real process-restart: You can declare a myApp::Restart() method in your subclass of QApplication. The following version works OK on both MS-Windows & MacOS:
Here is the code:
main.cpp:
mainwindow.h
The
slotReboot()
is the slot that will receive the signal of theQAction
I'm going to show in the mainwindow.cppmainwindow.cpp
First initialize
EXIT_CODE_REBOOT
:and declare a
QAction
pointer:then in the
MainWindow
constructor:And finally you need to send the signal (in the part of your code you need), in this way:
I did the code I showed following these instructions: How to make an application restartable - Qt Wiki
Assuming that 1337 is your restart code:
main.cxx
myClass.cxx
This slight variation on Rubenvb's idea works with PyQt.
clearSettings
is the method that triggers the restart.Take a look at How to restart an application thread on qtcentre.org, where muisei gives this code
I'm taking the other answers solutions, but better. No need for pointers, but there is a need for a
;
after thewhile
statement of ado { ... } while( ... );
construct.