Материал из C\C++ эксперт
Set Palette before paint
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#include <QtGui>
class MyWidget : public QWidget
{
public:
MyWidget();
protected:
void paintEvent(QPaintEvent *);
};
MyWidget::MyWidget()
{
QPalette palette(MyWidget::palette());
palette.setColor(backgroundRole(), Qt::white);
setPalette(palette);
}
void MyWidget::paintEvent(QPaintEvent *)
{
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.setPen(Qt::darkGreen);
painter.drawRect(1, 2, 6, 4);
painter.setPen(Qt::darkGray);
painter.drawLine(2, 8, 6, 2);
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyWidget widget;
widget.show();
return app.exec();
}
