QDialog/QWidget is closing after init

[fem_dev]

Here is the main file that creates a App object called w.

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    App w;
    w.show();
    return a.exec();
}

Here is the App initialization, where I create another window using QDialog. The name of this class is Plot.

App::App(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::App)
{
    ui->setupUi(this);

    Plot p(this);
    p.setModal(true);
    p.show();
...
}

Why the Plot QDialog window is closing after the show() method?

[SGaist]

Hi,

Because the variable p is on the stack and is local to the constructor. The show method being not blocking and the constructor ending after the call to show, p is destroyed immediately.

[fem_dev]

@fem_dev
I found:

p.exec();

[VRonin]

@fem_dev

NOPE! do not block the execution of constructors, App would live in a dangerous limbo if you do that

[SGaist]

Watch out, you are blocking your application until you close your dialog. Is that really what you want ?

[fem_dev]

Sorry guys...you two are right...
I'm doing this wrong...
thanks!