CMyClass: public QWidqet
{
...
QPainter    m_dc;
QPixmap    m_ScrBuf;
...
};
CMyClass::paintEvent(QPaintEvent *  e )
{
m_dc.begin(&m_ScrBuf);
AnyDraw(m_dc);
m_dc.end();

m_dc.begin(this);
m_dc.drawPixmap( 0, 0, m_ScrBuf );
m_dc.end();
}