Qt Code:
  1. void MainWindow::mousePressEvent(QMouseEvent *f)
  2. {
  3. point=f->pos();
  4. y=1;
  5. update();
  6. }
  7.  
  8. void MainWindow::paintEvent(QPaintEvent *e)
  9. {
  10. QPainter painter(this);
  11. QPen linepen(Qt::red);
  12. linepen.setCapStyle(Qt::RoundCap);
  13. linepen.setWidth(30);
  14. painter.setRenderHint(QPainter::Antialiasing,true);
  15. painter.setPen(linepen);
  16. if(y==1)
  17. painter.drawPoint(point);
  18.  
  19. }
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i have used the code. but draws only single point. when i click to draw a second point the first point will disappear. at a time only one point will appear..