QGraphicsView简单Demo

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    MainWindow w;

    //w.show();

    QGraphicsScene scene;

    QLineF line(0,0,500,500);

    scene.addLine(line);

    scene.addText("Hello, world!");

    QGraphicsView view(&scene);

    view.show();

    return a.exec();

}