qt turn off the display of the parent form subform

In the main window
{
child window class object a = new child window class;
Connect (Object a, SIGNAL signal (subclass), this, SLOT (slot function in the parent class);
}
so click send closed subwindow signal, would be the parent window. then on it. If the signals do not understand the information you can go online to see signals

Subform emit signals sent to the parent window function