Problem with QList

[just-in]

Hello everyone,

I'm relatively new to Qt and to programming as a whole. So be clement

My system is Windows 7, I am using Qt 5.1 with MinGW 32bit.

My problem:

I have a dialog that reads data from an sqlite database and writes it in a QList object. This QList contains objects of a C++ class I created (the class is called 'Card' and contains eight different QStrings).

QList<Card*>* newcard = new QList<Card*>;

QList<Card*>* newcard = new QList<Card*>;

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I have one label on my dialog that should display a QString from the first object of my QList.

ui->textlabel->setText(newcard->takeAt(0)->getfront());

ui->textlabel->setText(newcard->takeAt(0)->getfront());

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This works fine, the label is correctly displaying the QString. But then I want to change the text of the label when clicking a pushbutton.

void MyDialog::on_pushbutton_clicked()
{
    ui->textlabel->setText(newcard->takeAt(0)->getback());
}

void MyDialog::on_pushbutton_clicked()
{
    ui->textlabel->setText(newcard->takeAt(0)->getback());
}

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And this produces a SIGSEGV and the program crashes. I tried to fix the problem with different approaches, but none of them worked. The following code works neither:

QMessageBox::information(this,"Title",QString::number(newcard->count()));

QMessageBox::information(this,"Title",QString::number(newcard->count()));

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I also cannot transmit the QList to another dialog and work with it there. It crashes as well.


I think this problem has a simple solution and I am just to much of an amateur to see that. Please help me!

Well this thread should probably be in the newbie section, but I don't know how to move the thread...sorry.