Draw with QPainter in a label

Isidro Perla

Hello, i want to know how can I draw a rectangle in a ui label, for exaple ui->label_2, Here is current code, but only draw in the window.

void MainWindow::paintEvent(QPaintEvent *event){

QPainter painter(this);

QPen pen;
pen.setColor(Qt::blue);
painter.drawRect(QRect(80,120,200,100));

}

How Can I do to draw in ui->label_2 with QPainter????

JonB

@Isidro-Perla
By (subclassing and overriding) your QLabel's paintEvent, instead of that of the MainWindow. Every QWidget has its own https://doc.qt.io/qt-5/qwidget.html#paintEvent.

mrjj

Hi
You can also draw on a pixmap and then show that in the label.

void MainWindow::on_pushButton_released() {
  int h = ui->label->height();
  int w = ui->label->width();
  QPixmap pix(w, h);
  QPainter paint(&pix);
  pix.fill( Qt::white );
  paint.setPen(QColor(0, 0, 0, 255));
  paint.drawRect(QRect(80,120,200,100));
  ui->label->setPixmap(pix);
}