Qt Qwdget 汽车仪表知识点拆解7 图像绘制，旋转

void Widget::draw_number_pointer()
{
    QPainter painter(ui->label_numbre_1);
    painter.translate(204,204);
    painter.save();
    painter.rotate(pointer_angle);
    QRect rect(-202,-200,408,408);
    QRect source(0,0,408,408);
    painter.setRenderHint(QPainter::Antialiasing,true);
    painter.setRenderHint(QPainter::SmoothPixmapTransform,true);
    painter.drawPixmap(rect,*pixmap_pointer,source);
    painter.restore();
}