QT的sprintf重写；qt下内容按界面的缩放而缩放（不改变字体大小）

QT的sprintf重写

QString MainWindow::sprintf(const char *cformat, ...)
{
    va_list ap;
    va_start(ap, cformat);
    return QString::vasprintf(cformat, ap);
}

打印：
qDebug() << sprintf("%d", 12);

qt下内容按界面的缩放而缩放（不改变字体大小）

GraphicsView::GraphicsView(QWidget *parent)
    : QGraphicsView(parent)
{
    QGraphicsScene *scene = new QGraphicsScene(this);
    //

    QGraphicsProxyWidget *backItem = new QGraphicsProxyWidget;
    MainWindow *widget = new MainWindow;
    backItem->setWidget(widget);
    backItem->setFocus();
    //backItem->setCacheMode(QGraphicsItem::ItemCoordinateCache);//注释后不会有锯齿
    const QRectF r = backItem->rect();
    backItem->setTransform(QTransform()
                           .translate(-r.width()/2, -r.height()/2));

    //
    scene->addItem(backItem);
    //

    setScene(scene);
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setMinimumSize(50, 50);
    setViewportUpdateMode(FullViewportUpdate);
    setCacheMode(CacheBackground);
    setRenderHints(QPainter::Antialiasing
                   | QPainter::SmoothPixmapTransform
                   | QPainter::TextAntialiasing
                   );
}

void GraphicsView::resizeEvent(QResizeEvent *event)
{
    QGraphicsView::resizeEvent(event);
    fitInView(scene()->sceneRect(), Qt::KeepAspectRatio);
}

关于如何在fitInView中对graphicsview的边框做不显示处理

https://blog.csdn.net/ch593030323/article/details/41775195