MyWidget.h

#ifndef MYWIDGET_H
#define MYWIDGET_H
#include <QDialog>
#include <QtGui>
#include <QtCore>

class MyWidget:public QDialog
{
        Q_OBJECT
private:
    QPainter *p;
public:
    MyWidget(QDialog * obj = 0): QDialog(obj) {p=new QPainter; }
    virtual void paintEvent(QPaintEvent *){
        p->begin(this);
        p->setPen(QPen(Qt::black, 3));
        int n=2000;
        int i=0;
        while(i<2000){
            qreal fAngle = 2 * 3.14 * i / n;
            qreal x = 50 + cos(fAngle) *40;
            qreal y = 50 + sin(fAngle) *40;
            p->drawPoint(QPointF(x, y));
            i++;
        }
        p->end();
    }
};




#endif // MYWIDGET_H