Qt实现转动轮播图

Qt轮播图的实现代码，供大家参考，具体内容如下

qt轮播图简单的实现，功能会在后面完善

效果图：

这里我是用了QGraphicsScene+QGraphicsView+QGraphicsObject，其中对QGraphicsView和QGraphicsObject进行继承派生类功能进行了添加。时间有限，直接贴上关键代码部分供大家参考。

//pictrueitem.h
#ifndef PICTRUEITEM_H
#define PICTRUEITEM_H
#include <QGraphicsPixmapItem>
#include <QGraphicsItem>
#include <QGraphicsObject>
#include <QPixmap>
class PictrueItem : public QGraphicsObject
{
  Q_OBJECT

public:
  explicit PictrueItem(QGraphicsItem *parent = Q_NULLPTR);
  explicit PictrueItem(const QPixmap &pixmap, QGraphicsItem *parent = Q_NULLPTR);
  virtual ~PictrueItem();
  void setPixmap(const QPixmap &pixmap);
  QPixmap pixmap() const;
  virtual QRectF boundingRect() const;
  void setTransformationMode(Qt::TransformationMode mode);
  QPointF offset() const;
  void setOffset(const QPointF &offset);
  virtual int type()const;
  void setType(int type);
  int itemId()const;
  void setItemId(int id);

protected:
  void mousePressEvent(QGraphicsSceneMouseEvent *event);

  void mouseReleaseEvent(QGraphicsSceneMouseEvent *event);

  virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);

Q_SIGNALS:

  void clicked();
  void clickedId(int);

private:

  QPointF pressedScenePoint;
  QPointF m_offset;
  QPointF m_pos;
  Qt::TransformationMode mode;
  QPixmap m_pixmap;
  bool isPressed;
  int m_type;
  int m_id;
  qreal m_pointPercent;
};

#endif // PICTRUEITEM_H

//pictrueitem.cpp
#include "pictrueitem.h"
#include <QGraphicsSceneMouseEvent>
#include <QPainter>
#include <QDebug>
PictrueItem::PictrueItem(QGraphicsItem *parent)
  :QGraphicsObject(parent),
   isPressed(false),
   mode(Qt::SmoothTransformation),
   m_type(0),
   m_id(0),
   m_pointPercent((qreal)0.0)
{

}

PictrueItem::PictrueItem(const QPixmap &pixmap, QGraphicsItem *parent)
  :QGraphicsObject(parent),
   isPressed(false),
   mode(Qt::SmoothTransformation),
   m_type(0)
{
  m_pixmap = pixmap;
}

PictrueItem::~PictrueItem()
{

}

void PictrueItem::setPixmap(const QPixmap &pixmap)
{
  prepareGeometryChange();
  m_pixmap = pixmap;
  update();
}

QPixmap PictrueItem::pixmap() const
{
  return m_pixmap;
}

QRectF PictrueItem::boundingRect() const
{
  if(m_pixmap.isNull())
    return QRectF();
  return QRectF(m_offset, m_pixmap.size() / m_pixmap.devicePixelRatio());
}

void PictrueItem::setTransformationMode(Qt::TransformationMode mode)
{
  if (mode != this->mode)
  {
    this->mode = mode;
    update();
  }
}

QPointF PictrueItem::offset() const
{
  return m_offset;
}

void PictrueItem::setOffset(const QPointF &offset)
{
  m_offset = offset;
  if (m_offset == offset)
    return;
  prepareGeometryChange();
  m_offset = offset;
  update();
}

int PictrueItem::type() const
{
  return m_type;
}

void PictrueItem::setType(int type)
{
  m_type = type;
}

int PictrueItem::itemId() const
{
  return m_id;
}

void PictrueItem::setItemId(int id)
{
  m_id = id;
}


void PictrueItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
  //只响应鼠标左键
  if(event->button() == Qt::LeftButton)
  {
    pressedScenePoint = event->pos();
    isPressed = true;

  }
}

void PictrueItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
  if(event->button() == Qt::LeftButton){
    if(isPressed &&
        boundingRect().contains(event->pos()) &&
        boundingRect().contains(pressedScenePoint))
    {
      isPressed = false;
      emit clicked();
      emit clickedId(type());
    }
  }
}

void PictrueItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
  Q_UNUSED(widget);
  Q_UNUSED(option);
  painter->setRenderHint(QPainter::SmoothPixmapTransform,
              (this->mode == Qt::SmoothTransformation));

  painter->drawPixmap(m_offset, m_pixmap);

}								 
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