SIGSEGV when using inherited QGraphicsScene
I'm trying to inherit from a QGraphicsScene but somehow that crashes my program when I try to use it. I guess somewhere I'm missing a small thing, but I couldn't figure it out. Here is a minimal example of what I tried so far:
myscene.h
#ifndef MYSCENE_H
#define MYSCENE_H
#include <QGraphicsScene>
class MyScene : public QGraphicsScene
{
Q_OBJECT
QPen* pen_bg;
public:
explicit MyScene(QObject* parent=nullptr);
~MyScene();
};
#endif // MYSCENE_H
myscene.cpp
#include "myscene.h"
MyScene::MyScene(QObject* parent):
QGraphicsScene (parent)
{
pen_bg = new QPen(Qt::blue);
}
MyScene::~MyScene()
{
delete pen_bg;
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "myscene.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
MyScene *m_scene = new MyScene(this);
ui->graphicView->setScene(m_scene);
}
As soon as I call the setScene(m_scene) function, the program crashes with a SIGSEGV.
c++ qt inheritance qwidget qgraphicsscene
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
add a comment |
I'm trying to inherit from a QGraphicsScene but somehow that crashes my program when I try to use it. I guess somewhere I'm missing a small thing, but I couldn't figure it out. Here is a minimal example of what I tried so far:
myscene.h
#ifndef MYSCENE_H
#define MYSCENE_H
#include <QGraphicsScene>
class MyScene : public QGraphicsScene
{
Q_OBJECT
QPen* pen_bg;
public:
explicit MyScene(QObject* parent=nullptr);
~MyScene();
};
#endif // MYSCENE_H
myscene.cpp
#include "myscene.h"
MyScene::MyScene(QObject* parent):
QGraphicsScene (parent)
{
pen_bg = new QPen(Qt::blue);
}
MyScene::~MyScene()
{
delete pen_bg;
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "myscene.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
MyScene *m_scene = new MyScene(this);
ui->graphicView->setScene(m_scene);
}
As soon as I call the setScene(m_scene) function, the program crashes with a SIGSEGV.
c++ qt inheritance qwidget qgraphicsscene
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
add a comment |
I'm trying to inherit from a QGraphicsScene but somehow that crashes my program when I try to use it. I guess somewhere I'm missing a small thing, but I couldn't figure it out. Here is a minimal example of what I tried so far:
myscene.h
#ifndef MYSCENE_H
#define MYSCENE_H
#include <QGraphicsScene>
class MyScene : public QGraphicsScene
{
Q_OBJECT
QPen* pen_bg;
public:
explicit MyScene(QObject* parent=nullptr);
~MyScene();
};
#endif // MYSCENE_H
myscene.cpp
#include "myscene.h"
MyScene::MyScene(QObject* parent):
QGraphicsScene (parent)
{
pen_bg = new QPen(Qt::blue);
}
MyScene::~MyScene()
{
delete pen_bg;
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "myscene.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
MyScene *m_scene = new MyScene(this);
ui->graphicView->setScene(m_scene);
}
As soon as I call the setScene(m_scene) function, the program crashes with a SIGSEGV.
c++ qt inheritance qwidget qgraphicsscene
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
I'm trying to inherit from a QGraphicsScene but somehow that crashes my program when I try to use it. I guess somewhere I'm missing a small thing, but I couldn't figure it out. Here is a minimal example of what I tried so far:
myscene.h
#ifndef MYSCENE_H
#define MYSCENE_H
#include <QGraphicsScene>
class MyScene : public QGraphicsScene
{
Q_OBJECT
QPen* pen_bg;
public:
explicit MyScene(QObject* parent=nullptr);
~MyScene();
};
#endif // MYSCENE_H
myscene.cpp
#include "myscene.h"
MyScene::MyScene(QObject* parent):
QGraphicsScene (parent)
{
pen_bg = new QPen(Qt::blue);
}
MyScene::~MyScene()
{
delete pen_bg;
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "myscene.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
MyScene *m_scene = new MyScene(this);
ui->graphicView->setScene(m_scene);
}
As soon as I call the setScene(m_scene) function, the program crashes with a SIGSEGV.
c++ qt inheritance qwidget qgraphicsscene
c++ qt inheritance qwidget qgraphicsscene
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
asked Jan 3 at 7:49
Tom MekkenTom Mekken
735824
735824
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
If you use the UI file, you need to first call setupUi() before using it, otherwise the UI elements are not initialized. See docs: http://doc.qt.io/qt-5/designer-using-a-ui-file.html
Add
ui->setupUi(this);
to your MainWindow constructor.
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
If you use the UI file, you need to first call setupUi() before using it, otherwise the UI elements are not initialized. See docs: http://doc.qt.io/qt-5/designer-using-a-ui-file.html
Add
ui->setupUi(this);
to your MainWindow constructor.
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
add a comment |
If you use the UI file, you need to first call setupUi() before using it, otherwise the UI elements are not initialized. See docs: http://doc.qt.io/qt-5/designer-using-a-ui-file.html
Add
ui->setupUi(this);
to your MainWindow constructor.
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
add a comment |
If you use the UI file, you need to first call setupUi() before using it, otherwise the UI elements are not initialized. See docs: http://doc.qt.io/qt-5/designer-using-a-ui-file.html
Add
ui->setupUi(this);
to your MainWindow constructor.
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
If you use the UI file, you need to first call setupUi() before using it, otherwise the UI elements are not initialized. See docs: http://doc.qt.io/qt-5/designer-using-a-ui-file.html
Add
ui->setupUi(this);
to your MainWindow constructor.
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
answered Jan 3 at 8:47
llllllllllllllllllll
13.8k41742
13.8k41742
add a comment |
add a comment |
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