Simple questions

[assismvla]

I create a QDialog and insert a QPushButton, which when clicked calls a QMainWindows, but QMainWindows only flashes on the screen, and will not appear.

here is the simple code:

login.h
private slots:
    void Pushbutton_ok_click();
 
login.cpp
connect(ui->pushButton_OK,SIGNAL(clicked()),this,SLOT(Pushbutton_ok_click()));
 
void Login::Pushbutton_ok_click()
{
MainWindow W;
W.show();
}

login.h
private slots:
    void Pushbutton_ok_click();

login.cpp
connect(ui->pushButton_OK,SIGNAL(clicked()),this,SLOT(Pushbutton_ok_click()));

void Login::Pushbutton_ok_click()
{
MainWindow W;
W.show();
}

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[norobro]

Simple question in return (and a big hint): what is the life of a widget created on the stack?

[assismvla]

ok. Where a have to create it?

[norobro]

Here at the bottom of the page is a Qt related explanation.