Qt转动轮播图的实现方法

这篇文章主要讲解了Qt转动轮播图的实现方法，内容清晰明了，对此有兴趣的小伙伴可以学习一下，相信大家阅读完之后会有帮助。

创新互联为您提适合企业的网站设计让您的网站在搜索引擎具有高度排名，让您的网站具备超强的网络竞争力！结合企业自身，进行网站设计及把握，最后结合企业文化和具体宗旨等，才能创作出一份性化解决方案。从网站策划到网站制作、做网站，我们的网页设计师为您提供的解决方案。

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：

Qt转动轮播图的实现方法

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 
#include 
#include 
#include 
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 
#include 
#include 
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);

}

//pictrueview.h
#ifndef PICTRUEVIEW_H
#define PICTRUEVIEW_H
#include 

class PictrueView : public QGraphicsView
{
  Q_OBJECT

public:
  PictrueView(QWidget *parent = Q_NULLPTR);
  virtual ~PictrueView();
protected:
  void resizeEvent(QResizeEvent *event);
public:
Q_SIGNALS:
  void sizeChanged(const QSize &);
};

#endif // PICTRUEVIEW_H

//pictrueview.cpp
#include "pictrueview.h"
#include 
PictrueView::PictrueView(QWidget *parent)
  :QGraphicsView(parent)
{

}

PictrueView::~PictrueView()
{
  //none
}

void PictrueView::resizeEvent(QResizeEvent *event)
{
  emit sizeChanged(event->size());
  return QGraphicsView::resizeEvent(event);
}

下面那行按钮实现

//pictruebutton.h
#ifndef PICTRUERADIOBUTTON_H
#define PICTRUERADIOBUTTON_H
#include 

class PictrueButton : public QAbstractButton
{
  Q_OBJECT

public:
   explicit PictrueButton(QWidget *parent = Q_NULLPTR);
  ~PictrueButton();
  int id()const;
  void setId(int id);
Q_SIGNALS:
  void entered();
  void entered(int);
protected:
  virtual void paintEvent(QPaintEvent *);
  virtual void enterEvent(QEvent *event);
  virtual void leaveEvent(QEvent *event);
private:
  bool m_isSelected;
  int m_id;
};

#endif // PICTRUERADIOBUTTON_H

//pictruebutton.cpp
#include "pictruebutton.h"
#include 
#include 
#include 
#include 
PictrueButton::PictrueButton(QWidget *parent)
  :QAbstractButton(parent),
   m_isSelected(false),
   m_id(0)
{
  setCheckable(true);
  setFixedSize(50,10);
}

PictrueButton::~PictrueButton()
{

}

int PictrueButton::id() const
{
  return m_id;
}

void PictrueButton::setId(int id)
{
  m_id = id;
}

void PictrueButton::paintEvent(QPaintEvent *)
{
  QPainter painter(this);
  QRectF drawRect = this->rect();
  QPainterPath drawPath;
  qDebug()<

//qmainWindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 
#define RAW_VIEW_SIZE QSize(476,414)
#define SCALE_VIEW_PIXMAP (qreal)2/1 //View与图片比例
#define SCALE_BIG_SMALL (qreal)2/1 //图片大小比例
//P1-P8，8个位置，根据需要改动
#define P1 (qreal)0.00
#define P2 (qreal)0.25
#define P3 (qreal)0.50
#define P4 (qreal)0.75
#define P5 (qreal)1.00
#define P6 P4
#define P7 P3
#define P8 P2
#define MID_TYPE 2
#define FPS 60//帧数，每秒
#define DURATION_MS 500//移动一次图元经过时间,毫秒，不得低于帧数

namespace Ui {
class MainWindow;
}
class QGraphicsScene;
class QButtonGroup;
class MainWindow : public QMainWindow
{
  Q_OBJECT

public:
  enum Rules:int{
    RuleA = 1,
    RuleB = -1,
    RuleC = 2,
    RuleD = -2
  };

  explicit MainWindow(QWidget *parent = 0);
  ~MainWindow();
  int getIndexByRules(int oldIndex,int rule);
  template
  void rollList(QList &oldList, int dir, int count);
  void rollItem(int rollDir,unsigned rollCount);
public Q_SLOTS:
  void timerOutFunc(); 
  void nextItem();
  void previousItem();
  void clickedItemRoll(int type);
protected:

private:
  Ui::MainWindow *ui;
  QTimer *m_timer;
  QGraphicsScene *m_scene;
  QLineF midLine;
  QList pointList;
  QList pixmapList;
  QList zValueList;
  QList pixmapScaleList;
  int m_index;
  Rules currentRule;
  unsigned m_rollCount;
  QButtonGroup *btnGroup;
  bool btnMoveEnable;
};

#endif // MAINWINDOW_H

下面是滚动的关键代码

void MainWindow::timerOutFunc()
{
  for(int i = 0; i<8; i++)
  {
    if(qAbs(midLine.pointAt(pointList[getIndexByRules(i,dir)]).x()-itemList[i]->pos().x())setPos(midLine.pointAt(pointList[getIndexByRules(i,dir)]));
      //设置新的显示优先级
      itemList[i]->setScale(pixmapScaleList[getIndexByRules(i,dir)]);
      //设置新的类型
      itemList[i]->setType(getIndexByRules(i,dir));
      //i==7-->最后一个图元移动完成
      finishList.append(i);
      if(finishList.size() == 8)
      {
        //循环旋转图元表和图片表
        rollList(itemList,dir,1);
        rollList(pixmapList,dir,1);
        for(int i = 0; i<8; i++)
          itemList[i]->setZValue(zValueList[i]);
        m_timer->stop();
        finishList.clear();
        if(btnGroup->checkedId()!=itemList[MID_TYPE]->itemId())
          btnGroup->button(getIndexByRules(btnGroup->checkedId(),dir))->setChecked(true);
        if(--m_rollCount)
        {
          if(dir == 1)
            nextItem();
          else
            previousItem();
        }
        break;
      }
    }
    else
    {
      //按计算好的移动单位移动一次
      itemList[i]->setPos(QPointF(itemList[i]->pos().x()+unitList[i],itemList[i]->pos().y()));
      //转换因子不是1.0时进行转换设置
      if(transScaleList[i] != (qreal)1.0)
      {
        itemList[i]->setScale(itemList[i]->scale()*transScaleList[i]);
      }
    }
    m_scene->invalidate();
  }
}

void MainWindow::rollItem(int rollDir, unsigned rollCount)
{
  if(m_timer->isActive())
    return;
  //清除之前的空间差列表和移动单位列表
  m_rollCount = rollCount;
  spaceList.clear();
  unitList.clear();
  transScaleList.clear();
  dir = rollDir;
  qDebug()<<"rollCount"<pos().x());//计算移动总距离
    unitList.append(spaceList[i]/(FPS*DURATION_MS/1000));//计算移动单个距离
    transScaleList.append(pow(pixmapScaleList[getIndexByRules(i,dir)]/pixmapScaleList[i],\
               (qreal)1/(FPS*DURATION_MS/1000)));//计算增长倍数
  }

  //启动定时器
  m_timer->start();

}

void MainWindow::nextItem()
{
  rollItem(1,1);
}

void MainWindow::previousItem()
{
  rollItem(-1,1);
}

看完上述内容，是不是对Qt转动轮播图的实现方法有进一步的了解，如果还想学习更多内容，欢迎关注创新互联行业资讯频道。

当前题目：Qt转动轮播图的实现方法
网站链接：http://njwzjz.com/article/pdssoo.html

NEWS

网站建设资讯

Qt转动轮播图的实现方法

其他资讯