Access Violation - Crashing Application

[LIRiot]

#ifndef TIMERWINDOW_H
#define TIMERWINDOW_H
 
#include <QMainWindow>
#include <QMenu>
#include <QAction>
#include <QMenuBar>
 
class TimerWindow : public QMainWindow
{
    Q_OBJECT
    private:
        QMenu* File_Menu;
    public:
        explicit TimerWindow(QWidget *parent = 0);    signals:
 
    public slots:
 
};

#ifndef TIMERWINDOW_H
#define TIMERWINDOW_H

#include <QMainWindow>
#include <QMenu>
#include <QAction>
#include <QMenuBar>

class TimerWindow : public QMainWindow
{
    Q_OBJECT
    private:
        QMenu* File_Menu;
    public:
        explicit TimerWindow(QWidget *parent = 0);    signals:

    public slots:

};

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#include "TimerWindow.h"
 
TimerWindow::TimerWindow(QWidget *parent) : QMainWindow(parent)
{
    File_Menu = menuBar()->addMenu("Test");
}

#include "TimerWindow.h"

TimerWindow::TimerWindow(QWidget *parent) : QMainWindow(parent)
{
    File_Menu = menuBar()->addMenu("Test");
}

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I have simplified my code and tested the above I am not sure what I am doing wrong here. It continues to crash on start over and over. Anyone have ideas on what I have done wrong?

Error String: exited with code -1073741819

[franz]

Convert the error code to hex and search through the msdn to find out what that error code means. Then you can decide what should be done next (with some help from us, maybe).

[LIRiot]

I've done this, the error-code means there is an access violation. Everything I read says that it has to do with accessing memory without the proper privileges. However, unless I am missing something, the code is proper.

[0xC0000005]

[ChrisW67]

Have you single-stepped your program to find which line triggers the crash. We don't have your startup code so we would only be guessing.

Access violation: typically caused by dereferencing a null or otherwise invalid pointer.

[LIRiot]

File_Menu = menuBar()->addMenu("Test");

That is the line that crashes. It will run fine without that line. I have tried also changing it to:

File_Menu = new QMenu();

That crashes as well.

I also tried doing a local variable, it works fine. I tried changing the name of the "File_Menu" variable, it had no affect. I just don't understand what happened here.

[squidge]

We need more code - is menuBar() returning a valid pointer?

[LIRiot]

Also:

File_Menu = NULL; //Changing to this also causes an error.

[ChrisW67]

We need more code - is menuBar() returning a valid pointer?

It should be, the QMainWindow::menuBar() say it will create an empty menu bar if one does not exist.

File_Menu = NULL; //Changing to this also causes an error.

This makes no sense. You should clean and rebuild the source because clearly there is some major internal disconnect.

[LIRiot]

*Sigh*

Copied all the source and rebuilt it all from a new project and it fixed. Any ideas what would cause this to happen? Is there an easier way to fix such problems? Is there a file I can delete to force it to rebuild, or perhaps an option in the interface?

[ChrisW67]

Yes, use "make clean", "Build, Rebuild All" in Qt Creator, or the equivalent in Visual Studio. If you are using a shadow build area, just delete the shadow build directory.

There is possibly a runtime dependency between some of your code modules and the TimerWindow class that is not captured as source dependency. Changing the TimerWindow source has not caused the rebuild of the dependent module: the dependent module is expecting one binary arrangement of code, and the module is presenting another.