I want redraw one widget without hi's childs, how to use QProcess::sendEvent with QPaintEvent ? I try this, but this doesn't work:

Qt Code: 
  1. QPaintEvent *pe = new QPaintEvent(ui->groupBox->rect());
  2.     ui->groupBox->setAttribute(Qt::WA_WState_InPaintEvent, true);
  3.     QApplication::sendEvent(ui->groupBox, pe);
  4.     ui->groupBox->setAttribute(Qt::WA_WState_InPaintEvent, false);
To copy to clipboard, switch view to plain text mode 

But this code work and i dont' undrestand why:

Qt Code: 
  1. QPaintEvent *pe = new QPaintEvent(ui->groupBox->rect());
  2.     QPixmap pix(ui->groupBox->size());
  3.     pix.fill(Qt::white);
  4.     QPainter::setRedirected(ui->groupBox, &pix);
  5.     QApplication::sendEvent(centralWidget(), pe);
  6.     QPainter::restoreRedirected(ui->groupBox);
  7.     pix.save("file.jpg");
To copy to clipboard, switch view to plain text mode