setCursor(Qt::WaitCursor);

[Chicken Blood Machine]

void dlg::LongFunc()
{
     this->setCursor(Qt::WaitCursor);
     QApplication::processEvents();
     ...
     this->setCursor(Qt::ArrowCursor);
}

void dlg::LongFunc()
{
     this->setCursor(Qt::WaitCursor);
     QApplication::processEvents();
     ...
     this->setCursor(Qt::ArrowCursor);
}

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