QT draw text

void Widget::paintEvent(QPaintEvent *event)
{
    
    QPainter painter(this);
    QRectF rect(10.0,10.0,380.0,280.0);
    painter.setPen(Qt::red);
    painter.drawRect(rect);
    painter.setPen(Qt::blue);
    // Parameters ： The rectangle where the text is drawn 、 Align text in rectangle 、 Drawn text \n Can realize line feed 
    painter.drawText(rect,Qt::AlignHCenter,tr("AlignHCenter"));
    painter.drawText(rect,Qt::AlignLeft,tr("AlignLeft"));
    painter.drawText(rect,Qt::AlignRight,tr("AlignRight"));
    painter.drawText(rect,Qt::AlignHCenter,tr("AlignHCenter"));
    painter.drawText(rect,Qt::AlignBottom,tr("AlignBottom"));
    painter.drawText(rect,Qt::AlignCenter,tr("AlignCenter"));
    painter.drawText(rect,Qt::AlignBottom | Qt::AlignBottom,tr("AlignBottom/AlignBottom"));

    // Parameters ： The font family attribute 、 size 、 Is it in bold 、 Whether to use italics 
    QFont font(" Song style ",15,QFont::Bold,true);
    // Set underline 
    font.setOverline(true);
    // Set letter case 
    font.setCapitalization(QFont::SmallCaps);
    // Set the spacing between characters 
    font.setLetterSpacing(QFont::AbsoluteSpacing,10);
    // Using fonts 
    painter.setFont(font);
    painter.setPen(Qt::red);
    painter.drawText(120,80,tr("Hello world!"));
    painter.translate(100,100);
    painter.rotate(90);
    painter.drawText(0,0,tr("Hello Qt!"));
}