Qt：读写SVG

Qt：读写SVG

//绘制SVG图形：

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 (!numPixels.isNull()) {
//            scrollWithPixels(numPixels);
//        } else if (!numDegrees.isNull()) {
//            QPoint numSteps = numDegrees / 15;
//            scrollWithDegrees(numSteps);
//        }

//        event->accept();
//    }

//生成SVG图形：

#include <QApplication>
#include <QtGui>
#include <QtSvg>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

	QSvgGenerator svgGen;
	svgGen.setFileName("test.svg");

	QRectF rectangle(10.0, 20.0, 80.0, 60.0);
	QPainter painter;
	painter.begin(&svgGen);
	QPen pen(Qt::red);
	painter.setPen(pen);
	painter.drawEllipse(rectangle);
	rectangle.moveRight(100);
	painter.drawRect(rectangle);
	
	rectangle.moveRight(100);
 	QRectF source(0.0, 0.0, 70.0, 40.0);
 	QImage image("Greenstone.bmp");
	painter.drawImage(rectangle, image, source);
	 
	painter.end();
	
	return 0;
}