What I want to do now is simply show my .qrc picture to my scene, but something keep going wrong with my program. I've checked my path and it should be fine.
thanks in advance for the great help!
my picture is placed in a folder called "img" under my project.(img folder was newed by right clicking main.cpp and choose "show containing folder")
it shows [qrc_myresources.cpp] Error 1 as i run it, which quite confuse me. I've searched for stack overflow but didn't find the solution.
compile output:
00:30:13: Running steps for project shoot...
00:30:13: Configuration unchanged, skipping qmake step.
00:30:13: Starting: "/usr/bin/make"
/home/pd2vm/Qt5.9.2/5.9.2/gcc_64/bin/rcc -name myresources ../shoot/myresources.qrc -o qrc_myresources.cpp
RCC Parse Error: '../shoot/myresources.qrc' Line: 10 Column: 6 [expected tag]
Makefile:597: recipe for target 'qrc_myresources.cpp' failed
make: *** [qrc_myresources.cpp] Error 1
00:30:13: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project shoot (kit: Desktop Qt 5.9.2 GCC 64bit)
When executing step "Make"
00:30:13: Elapsed time: 00:00.
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QGraphicsScene>
#include <QGraphicsPixmapItem>
#include <QTimer>
#include <QKeyEvent>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
public slots:
virtual void keyPressEvent(QKeyEvent *e);
private:
Ui::MainWindow *ui;
QGraphicsScene *scene;
QGraphicsPixmapItem *player;
QTimer *timer;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow),
timer(new QTimer)
{
QGraphicsScene * scene = new QGraphicsScene(0,0,1200,880);
ui->setupUi(this);
ui->graphicsView->setScene(scene);
//player
player = new QGraphicsPixmapItem(QPixmap(":/img/whitedog.png"));
scene->addItem(player);
player->setPos(600, 880);
timer->start(10);
}
MainWindow::~MainWindow()
{
delete 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();
}
myresources.qrc
<RCC>
<qresource prefix="/">
<file>img/whitedog.png</file>
</qresource>
<RCC/>
I don't know much about Qt but that looks like xml and so shouldn't the slash go before the closing tag name. Like this:
<RCC>
...
</RCC>
Sorry if that's not the solution. Just the first thing I noticed.
Related
I'm a beginner in Qt, currently reading this : https://zetcode.com/gui/qt5/menusandtoolbars/
When I declare QActions in a QToolBar, the QPixmap objects (turned into QIcons) are not showing :
No icons, only text
However, the QPixmap images are actually showing when I declare a QMenu without the toolbar.
I am using Qt6 ; working on Fedora ; no warning shown on my compiler.
simple_menu.hpp
#ifndef SIMPLE_MENU_HPP
#define SIMPLE_MENU_HPP
#include <QMainWindow>
#include <QApplication>
class SimpleMenu : public QMainWindow
{
public:
SimpleMenu(QWidget *parent = nullptr);
};
#endif
simple_menu.cpp
#include "simple_menu.hpp"
#include <QMenu>
#include <QMenuBar>
#include <QToolBar>
#include <QIcon>
#include <QAction>
SimpleMenu::SimpleMenu(QWidget *parent)
: QMainWindow(parent)
{
QPixmap newpix("new.png");
QPixmap openpix("open.png");
QToolBar *toolbar = addToolBar("main toolbar");
toolbar->addAction(QIcon(newpix), "New File");
toolbar->addAction(QIcon(openpix), "Open File");
}
main.cpp
#include "simple_menu.hpp"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
SimpleMenu window;
window.resize(350, 250);
window.setWindowTitle("Tuto Toolbar");
window.show();
return app.exec();
}
Maybe the system cannot find your pictures. Please try to put the full file path (like :).
QPixmap newpix("c:\mydoc\pictures\new.png");
To check if the pictures are loaded, you can do something a bit different :
QPixmap newpix;
qDebug() << newpix.load("c:\mydoc\pictures\new.png");
the load method returns true or false in case of loading fail.
Anyway, if you want to embed your icons in the final EXE file, check the Qt resource system
It's a convenient system to achieve what you want to do, and to avoid dealing with storage paths on your local drives.
Good luck !
I am working on a simple project where I want to know the available printers, then connect to one of them and see if there are errors or not.
I have used QPrinterInfo class in order to know the available printer names, then in order to work with one of the available printers, I set its name using "printer.setPrinterName("desired printer name")".
In order to know if there are some errors related to this printer (named as desired printer name), I searched and find out I have to use QPrinter::Error and then handle the errors.
My question is that what kinds of error can occur when using QPrinter::Error inside my if statement(in the following code)? If no papers exists inside the printer, will using QPrinter::Error throw an error? In general, how can I know what kinds of error I can handle and how to handle them?
code:
mainwindow.h:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QtPrintSupport/QPrinter>
#include <QtPrintSupport/QPrinterInfo>
#include <QtPrintSupport/QPrintDialog>
#include <QList>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = nullptr);
~MainWindow();
QPrinter printer;
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QPrinterInfo PrinterInfo;
qDebug() << QStringList(QPrinterInfo::availablePrinterNames());
if (QPrinterInfo::availablePrinterNames().isEmpty())
{
qDebug() << " printer not found ";
}
printer.setPrinterName("desired printer name");
if (printer.printerState() == QPrinter::Error)
{
qDebug() << "there is an error";
}
}
MainWindow::~MainWindow()
{
delete 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();
}
Followings are my experience with QPrinter in Linux which built on CUPS. So if you are planning to use it on Windows it might be a totally difference experience than mine. But I think error checking in Linux contains a lot of uncertainties.
I tried QPrinter::printerState() with HP 107w, it was always returning Idle even when printer is not plugged in. Same was happening with Xerox WorkCentre 3025 too. So I recommend you to not rely on QPrinter::PrinterState. Also documentation states that QPrinter::printerState
Returns the current state of the printer. This may not always be accurate (for example if the printer doesn't have the capability of reporting its state to the operating system).
I was printing to via QPainter.begin(printer). It only fails if printer does not connected when OS started. But once the printer available after a boot, it behaves like everything is going to be okay forever. It just queues up prints and when printer becomes available, fed up with paper, just prints everything it received before. I thought return value of QPrinter::newPage() would be good place to check if there is no paper and ask user to insert papers to continue. But nah, it never returns false neither.
My animation isn't working on this QPushButton quite the way I'm expecting.
Here's my mainwindow.cpp, as you can see nothing particularly weird here. On runtime the button appears as one might expect. I didn't have any particular movement in mind. I just wanted to see if I had set everything up correctly. As things are right now the button doesn't grow or move. What's strange here is that if I comment out the setShape.start() it defaults back to the size designated in the UI file.
My only guess thus far is that my MainWindow object isn't being displayed until after its constructor (containing the animation) has run its course. If this is the case, I'm wondering what I can do to get around it.
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QLabel>
#include <QPushButton>
#include <QPropertyAnimation>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QPropertyAnimation setShape(ui->pushButton, "geometry");
setShape.setDuration(1000);
setShape.setStartValue(QRect(500,300,500,500));
setShape.setEndValue(QRect(800,400,500,500));
setShape.start();
}
MainWindow::~MainWindow()
{
delete ui;
}
Here's my main.cpp
#include "mainwindow.h"
#include <QApplication>
#include <QPropertyAnimation>
#include <QPushButton>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
This is about as basic an animation as one could create, so I'm hoping that either my intuition on this is correct, or I'm making a silly mistake. Either way any help would be greatly appreciated.
A local variable is deleted after it finishes executing its scope, and that is what happens with setShape, it is eliminated when the constructor finishes executing, what you have to do is create a pointer so that it is maintained and establish the policy of destruction to DeleteWhenStopped:
QPropertyAnimation *setShape = new QPropertyAnimation(ui->pushButton, "geometry");
setShape->setDuration(1000);
setShape->setStartValue(QRect(500,300,500,500));
setShape->setEndValue(QRect(800,400,500,500));
setShape->start(QPropertyAnimation::DeleteWhenStopped);
I work on Qt GUI C++ project. I try to display image from resource files, and there are more requirements like playing slideshow photos.
I meet difficult when debugging, it just showed white screen. I thought the image was not loaded to GraphicsView. In in main.cpp and mainwindow.ui, I keep them like default, no editing.
So please help me to fix this problem. Thanks in advance
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPixmap>
#include <QGraphicsPixmapItem>
#include <QMessageBox>
#include <QGraphicsView>
#include <QStackedWidget>
#include <QGraphicsScene>
#include <QDataStream>
#include <QFile>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QPixmap file(":/rose.jpg");
QStackedWidget *temp = new QStackedWidget();
QGraphicsScene scene;
QGraphicsView view(&scene);
QGraphicsPixmapItem img(file);
scene.addItem(&img);
temp->addWidget(&view);
setCentralWidget(view);
}
MainWindow::~MainWindow()
{
delete ui;
}
Your QGraphicsView and QGraphicsScene instance are local variable, they will be destroyed when out of the MainWindow constructor scope.
please try it like this.
QGraphicsScene *scene = new QGraphicsScene(this);
QGraphicsView *view = new QGraphicsView(scene);
If it still does't work, please check your QPixmap file is null or not just like what #Wagmare say.
I am very new to Qt so that some Qt issues I can't figure out. I will really appreciate if somebody can help me.
I am trying to get rid of application window's frame and create an exit button in qml in order to exit the application. Hence, I make a program as following:
main.cpp
#include <QtGui/QApplication>
#include <QDeclarativeContext>
#include <QObject>
#include "qmlapplicationviewer.h"
#include "myclass.h"
#include "mainwindow.h"
Q_DECL_EXPORT int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyClass myClass;
MainWindow window;
window.rootContext()->setContextProperty("myObject", &myClass);
window.show();
return app.exec();
}
mainwindow.cpp
#include "mainwindow.h"
MainWindow::MainWindow(QWidget *parent) : QDeclarativeView(parent)
{
// No window decorations
setWindowFlags(Qt::FramelessWindowHint);
// Set QML file
setSource(QUrl::fromLocalFile("qml/Test2/main.qml"));
}
// Destructor.
MainWindow::~MainWindow()
{
}
myclass.cpp
#include <QDeclarativeEngine>
#include <QDeclarativeComponent>
#include <QDeclarativeContext>
#include <stdio.h>
#include "myclass.h"
MyClass::MyClass()
{
click_count = 0;
}
int MyClass::click_function(void)
{
click_count++;
fprintf(stderr, "CLICK COUNT in CPP: %d\n", click_count);
return click_count;
}
qml
MouseArea {
id: mouse_exit
anchors.fill: parent
onClicked: {
console.log("Click on exit button: ")
console.log("click count: ", myObject.click_function())
Qt.quit();
}
}
It compiles successfully, however, whenever I click on the exit button, the Qt error "Signal QDeclarativeEngine::quit() emitted, but no receivers connected to handle it" occurs. Based on my searching online for this issue, it seems like I have to connect the QDeclarativeEngine::quit() signal to the QApplication::quit() slot. But there isn't too much information for using connect() function. I tried many ways to use connect(), but I still couldn't know how to use it for this case.
Can anybody help me solve this problem? I will really really appreciate!
The syntax is:
connect(sender, SIGNAL(signalName(args)), receiver, SLOT(slotName(args)));
You can put it in your MyClass constructor:
connect(this, SIGNAL(quit()), qApp, SLOT(quit()));
Or in the main function, since connect() is a static function, as Slavic81 pointed out in the comment below.
Note that qApp is a macro for the global application.