QGraphicsPixmapItem不可选 [英] QGraphicsPixmapItem not selectable

问题描述

我想让 QGraphicsPixmapItem 在 QGraphicScene 上变得可选择（即可以更一般的点击方式），但不会。我实际修改 Qt 的图场景示例，其中 QGraphicsItem 的子类是可选的。非常感谢您的帮助。

I want my QGraphicsPixmapItem become selectable (i.e. clickable in more general way) on QGraphicScene but it doesn't. I'm actually modifying Qt's Diagram Scene sample, where QGraphicsItem's subclass is used and is selectable. I appreciate your help.

cpp代码（部分）：

cpp code (partial):

#include <iostream>
#include <QtGui>    
#include "overlayPixmapItem.h"

OverlayPixmapItem::OverlayPixmapItem(DiagramType diagramType, QMenu *contextMenu,
                                                   QPixmap img, QGraphicsItem *parent,
                                                   QGraphicsScene *scene)
    : QGraphicsPixmapItem(img, parent), QObject()
{
    myDiagramType = diagramType;
    myContextMenu = contextMenu;

    this->setAcceptsHoverEvents(true);
    this->setAcceptHoverEvents(true); //
    this->setAcceptedMouseButtons(Qt::LeftButton);
    this->setAcceptedMouseButtons(Qt::RightButton);
    this->acceptDrops();

    setFlag(QGraphicsItem::ItemIsMovable, true);
    setFlag(QGraphicsItem::ItemIsSelectable, true);
    this->setFlag(QGraphicsItem::ItemSendsGeometryChanges, true);
}
:

标题（部分）：

#ifndef OVERLAYPIXMAPITEM_H
#define OVERLAYPIXMAPITEM_H

#include <QGraphicsPixmapItem>
#include <QList>
#include <QObject>

class QPixmap;
class QGraphicsItem;
class QGraphicsScene;
class QTextEdit;
class QGraphicsSceneMouseEvent;
class QMenu;
class QGraphicsSceneContextMenuEvent;
class QPainter;
class QStyleOptionGraphicsItem;
class QWidget;
class QPolygonF;

class OverlayPixmapItem : public QObject, public QGraphicsPixmapItem
{
        Q_OBJECT

    public:
        enum { Type = UserType + 15 };
        enum DiagramType { Crosshair };

        OverlayPixmapItem(DiagramType diagramType, QMenu *contextMenu,
                                 QPixmap img, QGraphicsItem *parent = 0, QGraphicsScene *scene = 0);

        DiagramType diagramType() const { return myDiagramType; }
        QPolygonF polygon() const { return myPolygon; }
        int type() const { return Type;}

    protected:
        void contextMenuEvent(QGraphicsSceneContextMenuEvent *event);
        QVariant itemChange(GraphicsItemChange change, const QVariant &value);
        void hoverEnterEvent ( QGraphicsSceneHoverEvent * event );
        void hoverLeaveEvent ( QGraphicsSceneHoverEvent * event );

    public: signals:
        void mouseHoveredOnElem(OverlayPixmapItem *i);
        void mouseHoveredOutOfElem(OverlayPixmapItem *i);

    private:
        DiagramType myDiagramType;
        QPolygonF myPolygon;
        QMenu *myContextMenu;
};
#endif // OVERLAYPIXMAPITEM_H

推荐答案

在我的第一个注释，你调用 setAcceptedMouseButtons（）方法两次。

As pointed out in my first comment, you call setAcceptedMouseButtons() method twice. While the first call actually set the correct button to be accepted, the second call make this setting lost.

要接受这个项目上的两个按钮，您必须将Qt MouseButtons标志，这样：

To accept both buttons on this item, you have to combine Qt MouseButtons flags, this way :

item->setAcceptedMouseButtons(Qt::LeftButton|Qt::RightButton) ;

这篇关于QGraphicsPixmapItem不可选的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！