Russian Qt Forum

#include <QtGui/QGraphicsView>
class QPaintEvent;
class QGraphicsView;

class WorkArea : public QGraphicsView
{
    Q_OBJECT
public:
    WorkArea(QWidget *parent = 0);
protected:
    void paintEvent(QPaintEvent *event);
}

#include <QtGui/QPaintEvent>
#include "qpainter.h"
#include "workarea.h"

WorkArea::WorkArea(QWidget *parent) : QGraphicsView(parent)
{
}

void WorkArea::paintEvent(QPaintEvent *event)
{
    QPainter p;
    p.begin(this);
    p.setRenderHint(QPainter::Antialiasing, true);
    p.setPen(QPen(Qt::black, 12, Qt::DashDotLine, Qt::RoundCap));
    p.setBrush(QBrush(Qt::green, Qt::SolidPattern));
    p.drawEllipse(40, 40, 200, 120);
    p.drawLine(0,0,100,100);
    p.end();
}

MainWindow::MainWindow()
{
 ... бла-бла-бла
    grView = new WorkArea(this);
    grView->setFrameStyle(QFrame::NoFrame | QFrame::Plain);
 ...
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtGui>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);

        QPainter painter;

        painter.begin(this);

        QPointF         ptCenter(rect().center());
        QRadialGradient gradient(ptCenter, width() / 2, ptCenter);

        gradient.setColorAt(0, Qt::red);
        gradient.setColorAt(0.5, Qt::green);
        gradient.setColorAt(1, Qt::blue);
        painter.setBrush(gradient);
        painter.drawRect(rect());
        
        painter.end();

}

MainWindow::~MainWindow()
{
     delete ui;
}

Starting /mnt/data/programming/Qt/domino/domino...
QPainter::begin: Widget painting can only begin as a result of a paintEvent
QPainter::setBrush: Painter not active
QPainter::drawRects: Painter not active
QPainter::end: Painter not active, aborted