setWindowModality problem!!!

[opengpu2]

i use setWindowModality to dynamically change a QDockWidget's modality.
but i met a problem!

void MyDockWidget::closeEvent(QCloseEvent* event)
{
if (windowModality() == Qt::ApplicationModal)  //WindowModality also failed...
  setWindowModality(Qt::NonModal);

QDockWidget::closeEvent(event);
}

here i want to reset it back to non-modal....but after i close the modal one....the whole Qt app including the MainWindow and other windows Cannot clicked....the whole app seems be Frozen....i don;t know why...

[opengpu2]

it seems like the Mainwindow and other windows still keep the state while the QDockWidget is modal......frozen there...cannot click anywhere...
and i tried to setFocus to the Mainwindow...still not worked....

[opengpu2]

anyone know met this problem?

[alex_malyu]

As far as I understand modality should not be changed after widget is shown,
It is not simply a state, it is much more.
Question is why do you want to do it.
Mostly likely you should change the design to avoid this.
But here is what documentation says:
"Changing this property while the window is visible has no effect; you must hide() the widget first, then show() it again."