[Interest] QFileDialog: what's wrong with this minimal example
Hi all,
if I compile this stripped down minimal example
-
#include
#include
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QFileDialog fd(0, "Load from file",
QDir::currentPath(),
"All Files (*)");
//return a.exec();
}
---
I get the following run-time error:
QObject: Cannot create children for a parent that is in a different thread.
(Parent is QFileSystemWatcher(0x1770be0), parent's thread is
QThread(0x1734420), current thread is QFileInfoGatherer(0x1791c58)
It is compiled with QT5.0.0 and g++ (GCC) 4.8.0 20130113 (experimental):
make[2]: Entering directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/test/test4'
g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -fPIE -DQT_WIDGETS_LIB
-DQT_GUI_LIB -DQT_CORE_LIB
-I/opt/Qt5.0.0/5.0.0/gcc_64/mkspecs/linux-g++-64
-I../../../apps5/test/test4 -I/opt/Qt5.0.0/5.0.0/gcc_64/include
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtWidgets
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtGui
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtCore -I. -I. -o main.o
../../../apps5/test/test4/main.cc
make[1]: Entering directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
make[1]: Nothing to be done for `first'.
make[1]: Leaving directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
g++ -m64 -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64
-Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64/lib -o test4 main.o
-L/usr/X11R6/lib64 -L/opt/Qt5.0.0/5.0.0/gcc_64/lib -lQt5Widgets -lQt5Gui
-lQt5Core -lGL -lpthread
--
Wilhelm
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QFileDialog: what's wrong with this minimal example
Looks ok. But try calling a.exec() and using a singleshot zero timeout timer
(beforr a.exec()) to bring up the file dialog. Let us know if that works.
From: Wilhelm
To: Qt Interest
Sent: Monday, January 21, 2013 1:33 PM
Subject: [Interest] QFileDialog: what's wrong with this minimal example
Hi all,
if I compile this stripped down minimal example
-
#include
#include
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QFileDialog fd(0, "Load from file",
QDir::currentPath(),
"All Files (*)");
// return a.exec();
}
---
I get the following run-time error:
QObject: Cannot create children for a parent that is in a different thread.
(Parent is QFileSystemWatcher(0x1770be0), parent's thread is
QThread(0x1734420), current thread is QFileInfoGatherer(0x1791c58)
It is compiled with QT5.0.0 and g++ (GCC) 4.8.0 20130113 (experimental):
make[2]: Entering directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/test/test4'
g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -fPIE -DQT_WIDGETS_LIB
-DQT_GUI_LIB -DQT_CORE_LIB
-I/opt/Qt5.0.0/5.0.0/gcc_64/mkspecs/linux-g++-64
-I../../../apps5/test/test4 -I/opt/Qt5.0.0/5.0.0/gcc_64/include
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtWidgets
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtGui
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtCore -I. -I. -o main.o
../../../apps5/test/test4/main.cc
make[1]: Entering directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
make[1]: Nothing to be done for `first'.
make[1]: Leaving directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
g++ -m64 -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64
-Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64/lib -o test4 main.o
-L/usr/X11R6/lib64 -L/opt/Qt5.0.0/5.0.0/gcc_64/lib -lQt5Widgets -lQt5Gui
-lQt5Core -lGL -lpthread
--
Wilhelm
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QFileDialog: what's wrong with this minimal example
In Qt 4.8, all I did to get it working was do a fd.show() in between the
QFileDialog call and the a.exec().
It also works fine using the static call for QFileDialog::getOpenFileName
Scott
-Original Message-
From: interest-bounces+scott.bloom=onshorecs@qt-project.org
[mailto:interest-bounces+scott.bloom=onshorecs@qt-project.org] On Behalf Of
Wilhelm
Sent: Monday, January 21, 2013 10:33 AM
To: Qt Interest
Subject: [Interest] QFileDialog: what's wrong with this minimal example
Hi all,
if I compile this stripped down minimal example
-
#include
#include
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QFileDialog fd(0, "Load from file",
QDir::currentPath(),
"All Files (*)");
//return a.exec();
}
---
I get the following run-time error:
QObject: Cannot create children for a parent that is in a different thread.
(Parent is QFileSystemWatcher(0x1770be0), parent's thread is
QThread(0x1734420), current thread is QFileInfoGatherer(0x1791c58)
It is compiled with QT5.0.0 and g++ (GCC) 4.8.0 20130113 (experimental):
make[2]: Entering directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/test/test4'
g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -fPIE -DQT_WIDGETS_LIB
-DQT_GUI_LIB -DQT_CORE_LIB
-I/opt/Qt5.0.0/5.0.0/gcc_64/mkspecs/linux-g++-64
-I../../../apps5/test/test4 -I/opt/Qt5.0.0/5.0.0/gcc_64/include
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtWidgets
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtGui
-I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtCore -I. -I. -o main.o
../../../apps5/test/test4/main.cc
make[1]: Entering directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
make[1]: Nothing to be done for `first'.
make[1]: Leaving directory
`/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
g++ -m64 -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64
-Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64/lib -o test4 main.o
-L/usr/X11R6/lib64 -L/opt/Qt5.0.0/5.0.0/gcc_64/lib -lQt5Widgets -lQt5Gui
-lQt5Core -lGL -lpthread
--
Wilhelm
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QFileDialog: what's wrong with this minimal example
Am 21.01.2013 19:36, schrieb Jason H:
> Looks ok. But try calling a.exec() and using a singleshot zero timeout
> timer (beforr a.exec()) to bring up the file dialog. Let us know if that
> works.
That all works. I stripped down the example to bring only the run-time
error. Looks like a Qt5-error, because the error doesn't show up in Qt
4.8.3. e.g.
I tries various g++ versions witg Qt5, but the run-time error remains.
Any Qt5 hints?
>
>
>
>
> *From:* Wilhelm
> *To:* Qt Interest
> *Sent:* Monday, January 21, 2013 1:33 PM
> *Subject:* [Interest] QFileDialog: what's wrong with this minimal example
>
> Hi all,
>
> if I compile this stripped down minimal example
> -
> #include
> #include
>
> int main(int argc, char *argv[])
> {
> QApplication a(argc, argv);
> QFileDialog fd(0, "Load from file",
> QDir::currentPath(),
> "All Files (*)");
>
> //return a.exec();
> }
> ---
>
> I get the following run-time error:
>
> QObject: Cannot create children for a parent that is in a different thread.
> (Parent is QFileSystemWatcher(0x1770be0), parent's thread is
> QThread(0x1734420), current thread is QFileInfoGatherer(0x1791c58)
>
>
> It is compiled with QT5.0.0 and g++ (GCC) 4.8.0 20130113 (experimental):
>
> make[2]: Entering directory
> `/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/test/test4'
> g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -fPIE -DQT_WIDGETS_LIB
> -DQT_GUI_LIB -DQT_CORE_LIB
> -I/opt/Qt5.0.0/5.0.0/gcc_64/mkspecs/linux-g++-64
> -I../../../apps5/test/test4 -I/opt/Qt5.0.0/5.0.0/gcc_64/include
> -I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtWidgets
> -I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtGui
> -I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtCore -I. -I. -o main.o
> ../../../apps5/test/test4/main.cc
> make[1]: Entering directory
> `/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
> make[1]: Nothing to be done for `first'.
> make[1]: Leaving directory
> `/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
> g++ -m64 -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64
> -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64/lib -o test4 main.o
> -L/usr/X11R6/lib64 -L/opt/Qt5.0.0/5.0.0/gcc_64/lib -lQt5Widgets -lQt5Gui
> -lQt5Core -lGL -lpthread
>
> --
> Wilhelm
>
> ___
> Interest mailing list
> Interest@qt-project.org <mailto:Interest@qt-project.org>
> http://lists.qt-project.org/mailman/listinfo/interest
>
>
--
Wilhelm
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QFileDialog: what's wrong with this minimal example
Am 22.01.2013 19:46, schrieb nikita baryshnikov:
> Hi
>
> #include
>
> #include
>
>
> int main(int argc, char *argv[])
>
> {
>
> QApplication app(argc, argv);
>
> QFileDialog fd(0, "Load from file", QDir::currentPath(), "All
> Files (*)");
>
> // fd.exec();
>
> // return app.exec();
>
> }
>
>
> works good for mewithout any error:(
which qt version, which compiler / version did you use?
>
>
>
> On Mon, Jan 21, 2013 at 9:41 PM, Wilhelm <mailto:wilhelm.me...@fh-kl.de>> wrote:
>
> Am 21.01.2013 19:36, schrieb Jason H:
> > Looks ok. But try calling a.exec() and using a singleshot zero
> timeout
> > timer (beforr a.exec()) to bring up the file dialog. Let us know
> if that
> > works.
>
> That all works. I stripped down the example to bring only the run-time
> error. Looks like a Qt5-error, because the error doesn't show up in Qt
> 4.8.3. e.g.
>
> I tries various g++ versions witg Qt5, but the run-time error remains.
>
> Any Qt5 hints?
>
> >
> >
> >
> >
> ----
> > *From:* Wilhelm <mailto:wilhelm.me...@fh-kl.de>>
> > *To:* Qt Interest <mailto:interest@qt-project.org>>
> > *Sent:* Monday, January 21, 2013 1:33 PM
> > *Subject:* [Interest] QFileDialog: what's wrong with this minimal
> example
> >
> > Hi all,
> >
> > if I compile this stripped down minimal example
> > -
> > #include
> > #include
> >
> > int main(int argc, char *argv[])
> > {
> > QApplication a(argc, argv);
> > QFileDialog fd(0, "Load from file",
> > QDir::currentPath(),
> > "All Files (*)");
> >
> > //return a.exec();
> > }
> > ---
> >
> > I get the following run-time error:
> >
> > QObject: Cannot create children for a parent that is in a
> different thread.
> > (Parent is QFileSystemWatcher(0x1770be0), parent's thread is
> > QThread(0x1734420), current thread is QFileInfoGatherer(0x1791c58)
> >
> >
> > It is compiled with QT5.0.0 and g++ (GCC) 4.8.0 20130113
> (experimental):
> >
> > make[2]: Entering directory
> >
> `/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/test/test4'
> > g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -fPIE -DQT_WIDGETS_LIB
> > -DQT_GUI_LIB -DQT_CORE_LIB
> > -I/opt/Qt5.0.0/5.0.0/gcc_64/mkspecs/linux-g++-64
> > -I../../../apps5/test/test4 -I/opt/Qt5.0.0/5.0.0/gcc_64/include
> > -I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtWidgets
> > -I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtGui
> > -I/opt/Qt5.0.0/5.0.0/gcc_64/include/QtCore -I. -I. -o main.o
> > ../../../apps5/test/test4/main.cc
> > make[1]: Entering directory
> > `/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
> > make[1]: Nothing to be done for `first'.
> > make[1]: Leaving directory
> > `/home/lmeier/Software/qtwm/trunk/apps/apps5-build-QT5-Debug/lib'
> > g++ -m64 -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64
> > -Wl,-rpath,/opt/Qt5.0.0/5.0.0/gcc_64/lib -o test4 main.o
> > -L/usr/X11R6/lib64 -L/opt/Qt5.0.0/5.0.0/gcc_64/lib -lQt5Widgets
> -lQt5Gui
> > -lQt5Core -lGL -lpthread
> >
> > --
> > Wilhelm
> >
> > ___
> > Interest mailing list
> > Interest@qt-project.org <mailto:Interest@qt-project.org>
> <mailto:Interest@qt-project.org <mailto:Interest@qt-project.org>>
> > http://lists.qt-project.org/mailman/listinfo/interest
> >
> >
>
>
> --
> Wilhelm
>
> ___
> Interest mailing list
> Interest@qt-project.org <mailto:Interest@qt-project.org>
> http://lists.qt-project.org/mailman/listinfo/interest
>
>
--
Wilhelm
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QFileDialog: what's wrong with this minimal example
On 01/21/2013 07:33 PM, Wilhelm wrote:
> Hi all,
>
> if I compile this stripped down minimal example
> -
> #include
> #include
>
> int main(int argc, char *argv[])
> {
> QApplication a(argc, argv);
> QFileDialog fd(0, "Load from file",
> QDir::currentPath(),
> "All Files (*)");
>
> //return a.exec();
> }
> ---
>
> I get the following run-time error:
>
> QObject: Cannot create children for a parent that is in a different thread.
> (Parent is QFileSystemWatcher(0x1770be0), parent's thread is
> QThread(0x1734420), current thread is QFileInfoGatherer(0x1791c58)
Could you report this in the bug tracker?
--
Samuel
___
Interest mailing list
Interest@qt-project.org
http://lists.qt-project.org/mailman/listinfo/interest
Re: [Interest] QFileDialog: what's wrong with this minimal example
Hi, since I also ran into this on my machine, I created https://bugreports.qt-project.org/browse/QTBUG-29366 with an example and a bit of analysis. The underlying reason is that the creation of a QInotifyFileSystemWatcherEngine fails due to "Too many open files". Regards, Friedemann -- Friedemann Kleint Digia, Qt ___ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
