i want to test whether qt is supporting VNC or not. For that i have written a small layout program using Qt library.
the source code for the layout program is as follows:
layout.cpp
#include <QApplication>
#include <QHBoxLayout>
#include <QSlider>
#include <QSpinBox>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QWidget *window = new QWidget;
window->setWindowTitle("Enter The Age of the person");
QSpinBox *spinBox = new QSpinBox;
QSlider *slider = new QSlider(Qt::Horizontal);
spinBox->setRange(0, 130);
slider->setRange(0, 130);
QObject::connect(spinBox, SIGNAL(valueChanged(int)),
slider, SLOT(setValue(int)));
QObject::connect(slider, SIGNAL(valueChanged(int)),
spinBox, SLOT(setValue(int)));
spinBox->setValue(35);
QHBoxLayout *layout = new QHBoxLayout;
layout->addWidget(spinBox);
layout->addWidget(slider);
window->setLayout(layout);
window->show();
return app.exec();
}
i want to run this as server application on my linux PC.For that what i configured Qt and installed like this.
./configure -qt-gfx-vnc
make
make install
The program is working fine. But if i run the application as VNC server application like
./layout -qws -display VNC:0
i am encountering an error.it says that
"_X11TransSocketINETConnect() can't get address for VNC:6000: Temporary failure in name resolution"..
pls help me what i need to do.
Thanks
You did not configure Qt to use QWS, which is what you wanted.
For this reason, it looks like your app is silently ignoring the -qws option, and the -display VNC:0 option is causing it to try to connect to the X11 display number 0 on host VNC, which doesn't exist.
You need to pass the -embedded option when configuring Qt if you want to use QWS.
Related
I am searching "QCleanlooksStyle" belongs to which "QT +=". please help, ive centos 6.4 and Qt 5.3.
#include <QApplication>
#include <QCleanlooksStyle>
#include <QtWidgets>
#include "buttonbox.h"
int main( int argc, char **argv )
{
QApplication app( argc, argv );
app.setStyle( new QCleanlooksStyle );
ButtonBoxDialog dlg;
dlg.show();
return app.exec();
}
According to the docs:
QMotifStyle, QPlastiqueStyle, QCleanlooksStyle, and QCDEStyle are
replaced with a new fusion style. If your application depends on any
of these removed styles, you can either use the qtstyleplugins project
to get these styles or update your application to use the new fusion
style. For more details about this change, see
https://blog.qt.io/blog/2012/10/30/cleaning-up-styles-in-qt5-and-adding-fusion/.
So you must clone the project, compile it and install it:
git clone git://code.qt.io/qt/qtstyleplugins.git
cd qtstyleplugins/
qmake
make
sudo make install
Then you must set the style using the following (you should not modify the .pro):
app.setStyle("cleanlooks");
I am relatively new to Qt and was going through many tutorials. Everything was fine. All scripts compiled and ran.
Then, at some point, I am getting the error for even a new Qt widget application created with Qt Creator 4.3.1:
C:\ \Documents\111\main.cpp:-1: In function 'int qMain(int, char**)':
C:\ \Documents\111\main.cpp:6: error: variable 'QApplication a' has initializer but incomplete type
QApplication a(argc, argv);
^
C:\ \Documents\111\main.cpp:11: warning: control reaches end of non-void function [-Wreturn-type]
}
^
I am not sure what happened, yet seems like some setups were messed up.
QApplication is included, and not missing in the script.
111.pro
# Project created by QtCreator 2018-02-23T01:36:28
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = 111
TEMPLATE = app
DEFINES += QT_DEPRECATED_WARNINGS
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0
SOURCES += \
main.cpp \
mainwindow.cpp
HEADERS += \
mainwindow.h
FORMS += \
mainwindow.ui
main.cpp
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
mainview.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
It seems to me that this issue appeared after trying to run qt5.6_src.zip examples from https://en.ids-imaging.com/open-source.html.
Without completed code, I guess you need to add #include <QApplication> to main.cpp
The error message told you what is missing.
According to Qt's docs, the constructor's signature is QApplication(int &argc, char **argv).
Therefore, if you inherit from QApplication then the subclass's constructor must pass argc by reference. From your description, it appears that the constructor of your subclass is actually passing argc by value (i.e., int qMain(int, char**) ). That will cause some problems.
The issue is fixed by deleting the Qt folder and QtCreator folder in the <drive>:\Users\<username>\AppData\Roaming\QtProject and <drive>:\Users\<username>\AppData\Roaming\Qt. It stored incorrect settings, which I somehow setup by running open source scripts. For more information visit Where does QtCreator save its settings?.
This is my first time using QMap and I don't know what I'm doing wrong.
#include <QMap>
QMap<QString, int> name_sec_age;
name_sec_age.insert("willy", 593381460);
my errors are:
"unknown type name 'name_sec_age'"
and "expected unqualified id"
I'm using Qt Creator 4.0 with Qt 5.6 on a mac.
Side note: the run button on Qt Creator isn't available. To run my app I build it and then open the app from its path in finder. rather annoying.
You can't run code in the wild like that, it needs to be in a function.
#include <QMap>
#include <QString>
#include <QDebug>
int main() {
QMap<QString, int> name_sec_age;
name_sec_age.insert("willy", 593381460);
qDebug() << name_sec_age;
}
Your setup must be messed up somehow. Perhaps you'll have more luck by installing macports and using Qt/Qt Creator from there.
The following compiles just fine for me under Qt 5.5.1:
#include <QMap>
int main() {
QMap<QString, int> name_sec_age;
name_sec_age.insert("willy", 593381460);
}
I've tried to embed emacs in a Qt Application using QX11EmbedContainer, and works but with two important exception. First of all, here is the code:
#include <QX11EmbedWidget>
#include <QtGui>
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QX11EmbedContainer container;
container.show();
container.resize(500, 500);
QProcess* process = new QProcess(&container);
QString executable("emacsclient");
QStringList arguments;
arguments << "--parent-id" << QString::number(container.winId());
process->start(executable, arguments);
int status = app.exec();
process->close();
return status;
}
And the compilation and execution line (and the previous thrown of the emacs server):
$ emacs -q --daemon &
// filtered output
$ g++ test.cpp -lQtGui -lQtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4
$ ./a.out
And finally, the result:
But, when or if I try to write something in the minibuffer, the size of the widget is collapsed, and the focus is also lost:
If I make click in the (now shorter) widget, I can continue working with emacs without problems, but I should resize the window in order to emacs is expanded other time as originally.
Where is the problem?
Try using a layout.
Here is the Qt5 documentation on layout management.
hi i'm just trying to compile an easy project in qt
#include <QApplication>
#include <QPushButton>
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QPushButton bouton("Salut les Zéros, la forme ?");
bouton.show();
return app.exec();
}
but i have this error : /home/eid/test/easyprojet/main.cpp:1: error: QApplication: No such file or directory
can anyone help me ?
sorry for my english
In Qt5, it resides in , while in Qt4 it was .
In Qt5 you need to add QT += widgets to your .pro file.
It may be also because the project is not in the workspace of QT creator.
It happened with me before.
so,try to put the project in the workspace .