Unable to delete the widgets in sub-layout of a layout in Qt

Question

I am using Qt 5.5.0 for Windows. In a dialog using for login as well as register, I use a QVBoxLayout as the main layout of the dialog and add a QGridLayout to the mainLayout. W

Answer 1

You should use one of the setHidden( bool ), setVisible( bool ) functions. If you just use the removeWidget function which you did then you only remove it from the layout.

Answer 2

You are removing just from layout, not the parent widget, so they are shown in the widget not "layouted".

Try simply hiding them with setVisible(false), and setVisible(true) to show them again.

void LoginDialog::showRegister()
{
    ...
    useremailLabel->setVisible(true);
    ...
}

void LoginDialog::hideRegister()
{
    ...
    useremailLabel->setVisible(false);
    ...
}

Answer 3

If you truly want to get rid of the widgets, you should destruct them. If they were allocated on the heap, you should simply delete them: this deallocates their memory after destructing them.

Qt keeps track of widget lifetime and a widget being destructed automatically removes itself from its layout, and removes itself from its parent.