Qt：读写SVG

SvgView::SvgView(const QString &file, QWidget *parent)

: QWidget(parent)

{

doc = new QSvgRenderer(file, this); //QSvgRenderer将SVG图形绘制到绘图设备上

connect(doc, SIGNAL(repaintNeeded()), //文档需要更新时发出，通常用来实现动画效果

this, SLOT(update()));

}

void SvgView::paintEvent(QPaintEvent *)

{

QPainter p(this);

p.setViewport(0, 0, width(), height());

doc->render(&p);

}

QSize SvgView::sizeHint() const

{

if (doc)

return doc->defaultSize();

return QWidget::sizeHint();

}

void SvgView::wheelEvent(QWheelEvent *e)

{

const double diff = 0.1;

QSize size = doc->defaultSize();

int width = size.width();

int height = size.height();

if (e->delta() > 0) { //此函数已废弃，用pixelDelta() / angleDelta() instead.

width = int(this->width()+this->width()*diff);

height = int(this->height()+this->height()*diff);

} else {

width = int(this->width()-this->width()*diff);

height = int(this->height()-this->height()*diff);

}

resize(width, height);

}

// void MyWidget::wheelEvent(QWheelEvent *event)

// {

// QPoint numPixels = event->pixelDelta();

// QPoint numDegrees = event->angleDelta() / 8;

// if (!()) {

// scrollWithPixels(numPixels);

// } else if (!()) {

// QPoint numSteps = numDegrees / 15;

// scrollWithDegrees(numSteps);

// }

// event->accept();

// }