Congratulations to our 2022 Qt Champions!

Move a QGraphicsPixmapItem

  • I have a a character added via QgraphicsPixmapitem and now I want to move it by pressing the arrow keys on the keyboard. But I can't find a way. It gives compilation error. Help me please!

    moveship.h (header file for my QPixmapItem)

        #ifndef MOVESHIP_H
        #define MOVESHIP_H
        #include <QGraphicsPixmapItem>
        class moveship: public QGraphicsPixmapItem
            void keyPressEvent(QKeyEvent *event);
        #endif // MOVESHIP_H

    I am just checking if it recognises any key press or not.

    Implementation of keyPressEvent:

      #include "moveship.h"
      #include <QDebug>
      void moveship::keyPressEvent(QKeyEvent *event)
          qDebug() << "moved";

    My main source file:

        #include <moveship.h>
        int main(int argc, char *argv[])
            QApplication a(argc, argv);
            QGraphicsScene * scene = new QGraphicsScene();
            QGraphicsView * view = new QGraphicsView(scene);
            QPixmap q = QPixmap("://images/player.png");
                moveship * player = new moveship(q);
            return a.exec();

    Please help :(

  • If there is a compilation error why you did not post it?

  • Possibly the error is from the declaration of keyPressEvent

    virtual void keyPressEvent(QKeyEvent *event);

    It might be better to have this handled in the parent class. When a graphics item is selected (clicked) store this information and move the item from the parent when the right key presses are seen. You might have a problem with losing focus otherwise.