QT crashed when I try to do onglets->setCurrentIndex(0);

[mrjj]

So you do
QTabWidget *onglets = new QTabWidget(&fenetre);
(this is local variable)

Do you also have one in . h file ?
one named onglets

You are newing a new copy. not the one from .h file
so later u use a invalid pointer as its not newed. ( i guess)

can you please also show .h file ?

[f.lerdino]

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

class DiagramScene;

QT_BEGIN_NAMESPACE
class QAction;
class QToolBox;
class QSpinBox;
class QComboBox;
class QFontComboBox;
class QButtonGroup;
class QLineEdit;
class QGraphicsTextItem;
class QFont;
class QToolButton;
class QAbstractButton;
class QGraphicsView;
class QTabWidget;
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
MainWindow();

public slots:
void playaction();

private slots:
void sendToBack();
void about();
void setVariables(const QString &newValue);

private:
void createActions();
void createMenus();
void createToolbars();
void createVertbars();

/*QGraphicsView *view;*/

QAction *exitAction;
QAction *addAction;

QAction *toFrontAction;
QAction *sendBackAction;
QAction *aboutAction;

QAction *toPlayAction;

QMenu *fileMenu;
QMenu *itemMenu;
QMenu *aboutMenu;

QToolBar *textToolBar;
QToolBar *editToolBar;
QToolBar *pointerToolbar;

QComboBox *sceneScaleCombo;
QComboBox *fontSizeCombo;
QFontComboBox *fontCombo;

QToolBar *fontToolBar;

QLineEdit *textbox;

QWidget *fenetre;
QWidget *page1;
QWidget *page2;
QWidget *page3;
QTabWidget *onglets;

};

#endif // MAINWINDOW_H

[JonB]

@f.lerdino
I have no idea whether this matters/causes your problem, but you seem to have:

setCentralWidget(widget);
...
setCentralWidget(onglets);

Is that right?

[f.lerdino]

en fact i dont need the first one ... but nothing changed

[f.lerdino]

Question, Is it possible to pass the *onglets as argument in the function?

[mrjj]

Hi
you are doing that i ask in first post.

You have
QTabWidget *onglets; in h file but new another so that is why you crash.

/****************************/
QWidget fenetre; // this ones DIES as soon as functions ends. not good.

// 1 : Créer le QTabWidget
QTabWidget *onglets = new QTabWidget(&fenetre); THis one create a local variable,

It is not the one from .H ( and it cant be used outside the function)

So that is why you crash.

[JonB]

@f.lerdino
Yep, exactly as @mrjj has just written above!

[jsulm]

@f.lerdino One more issue is you create a local QWidget on the stack in the constructor:

QWidget fenetre;
QTabWidget *onglets = new QTabWidget(&fenetre);
``
That means it will be destroyed when the constructor finishes.

[JonB]

@mrjj

Purely OOI: I don't use Qt Creator/C++, but in this case where there is a class member variable named foo and then a function local variable also named foo is declared, does the Qt Creator "squiggle underline" the local variable warning that it "overrides the class variable", for the OP to notice? My PyCharm/Python IDE does do that....

[mrjj]

@JonB
Not per default. Maybe with c-lang code model.
I wish it did. :)

[JonB]

@mrjj
Upgrade to Python ;-) LMAO/ROFL

[mrjj]

@JonB
:)))
I would - if you give me visible scopes and remove that dreadful Self.
and what is up with ___Var to say its private :)
Joking aside, its really a nice editor. I assume the Pro version is even more
cool than the Community version.