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QT 拖拽 QListWidget发送，Qgraphicview接收_qmimedata拖拽缩略图

作者：weixin_40725706 | 2024-02-16 07:13:11

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qmimedata拖拽缩略图

Widget类发送

  1. setDragEnabled(true)函数以使该部件能接受拖放事件.

  1. 在widget类重写mousePressEvent()或mouseMoveEvent()函数中启动拖放，记住启动拖放就是调用QDrag对象的exec()函数，在此步把需要拖动的数据保存在QMimeData对象中。

  1.     QDrag *drag=new QDrag(this);
  2.     QMimeData *mimeData=new QMimeData;
  3.     mimeData->setText(currentItem()->text());
  4.     mimeData->setData("application/Units.list", encodedData);
  5.     drag->setMimeData(mimeData);
  6.     drag->exec(Qt::CopyAction|Qt::MoveAction);

//或者是调用setData发送自定义数据

  1. void MyListWidget::mouseMoveEvent(QMouseEvent *event)
  2. {
  3.     if (!(event->buttons()&Qt::LeftButton))
  4.         return;
  5.     if ((event->pos() - m_dragPosition).manhattanLength() < QApplication::startDragDistance())
  6.         return;
  7.     if (!m_dragItem)
  8.         return;
  9.     QDrag *drag = new QDrag(this);
  10.     QMimeData *mimeData = new QMimeData;
  11.     QString strtext = currentItem()->text();
  12.     if (strtext.isEmpty())
  13.     {
  14.         int row = currentRow() - 2;
  15.         QByteArray encodedData;
  16.         QDir dir1;
  17.         QString strdir = dir1.currentPath();
  18.         QString strfile = strdir + "/svg/" + m_strList[row];
  19.         QDataStream stream(&encodedData, QIODevice::WriteOnly);
  20.         {
  21.             QPixmap pixmap(strfile);
  22.             stream << pixmap;
  23.         }
  24.         mimeData->setData("draglist", encodedData);
  25.     }
  26.     else
  27.     {
  28.         mimeData->setData("draglist", strtext.toUtf8());
  29.     }
  30.     drag->setMimeData(mimeData);
  31.  
  32.     drag->exec(Qt::CopyAction | Qt::MoveAction);
  33. }

使用场景类接收拖拽

  1. 调用setAcceptDrops(true).使能接收数据。

  1. 主要重写dragEnterEvent、dragMoveEvent、dropEvent。

  1.      void dragEnterEvent(QGraphicsSceneDragDropEvent *event) override;
  2.      void dragMoveEvent(QGraphicsSceneDragDropEvent *event) override;
  3.      void dropEvent(QGraphicsSceneDragDropEvent *event) override;
  1.  
  2. void MyGraphicsScene::createRect(const QPointF &pt)
  3. {
  4.     MyGraphicsRectItem *item=new MyGraphicsRectItem;
  5.     item->setPos(pt);
  6.     qDebug() << "rect pos:" << pt.x() << pt.y();
  7.     item->setFlags(QGraphicsItem::ItemIsSelectable|QGraphicsItem::ItemIsMovable);
  8.     addItem(item);
  9. }
  10.  
  11. void MyGraphicsScene::createLine(const QPointF &pt)
  12. {
  13.     MyGraphicsLineItem *item=new MyGraphicsLineItem;
  14.     item->setPos(pt);
  15.     item->setFlags(QGraphicsItem::ItemIsSelectable|QGraphicsItem::ItemIsMovable);
  16.     addItem(item);
  17. }
  18.  
  19. void MyGraphicsScene::dragEnterEvent(QGraphicsSceneDragDropEvent *event)
  20. {
  21.     if(event->mimeData()->hasFormat("text/plain")){
  22.         event->acceptProposedAction();
  23.     }
  24. }
  25.  
  26. void MyGraphicsScene::dropEvent(QGraphicsSceneDragDropEvent *event)
  27. {
  28. //    QGraphicsScene::dropEvent(event);
  29.  
  30.     if (event->mimeData()->hasFormat("text/plain"))
  31.     {
  32.  
  33.         QString text=event->mimeData()->text();
  34.         if(text==tr("直线"))
  35.         {
  36.             createLine(event->scenePos());
  37.         }
  38.         else if(text==tr("矩形"))
  39.         {
  40.             createRect(event->scenePos());
  41.         }
  42.         else{
  43.  
  44.         }
  45.  
  46.         event->acceptProposedAction();
  47.     }
  48.  
  49. }
  50.  
  51. void MyGraphicsScene::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
  52. {
  53.     event->accept();
  54. }

测试发现：item在视图存放的位置有些问题？前面位置没法固定，添加多了就ok.

使用视图类来处理拖拽的接收（推荐使用这种办法）

使用视图类可以保证item在视图存放的位置就是鼠标的位置。

  1. 场景类就不用重写dragEnterEvent、dragMoveEvent、dropEvent。

  1. 视图类调用setAcceptDrops(true)允许接收。

  1. 视图类重写dragEnterEvent、dragMoveEvent、dropEvent。

  1. #ifndef MYGRAPHICSVIEW_H
  2. #define MYGRAPHICSVIEW_H
  3.  
  4. #include <QObject>
  5. #include <QGraphicsView>
  6.  
  7. class MyGraphicsView : public QGraphicsView
  8. {
  9. public:
  10.     MyGraphicsView(QWidget *parent=0);
  11.     ~MyGraphicsView();
  12.  
  13. protected:
  14.     void dragEnterEvent(QDragEnterEvent *event);
  15.     void dragMoveEvent(QDragMoveEvent *event) ;
  16.     void dropEvent(QDropEvent *event);
  17. };
  18. #endif // MYGRAPHICSVIEW_H
  19.  
  20.  
  21. #include "mygraphicsview.h"
  22. #include "mygraphicsscene.h"
  23. #include <QDragEnterEvent>
  24. #include <QMimeData>
  25. #include <QDebug>
  26. #include    <QMouseEvent>
  27. #include    <QPoint>
  28.  
  29. #if _MSC_VER >=1600
  30.  
  31. #pragma execution_character_set("utf-8")
  32.  
  33. #endif
  34.  
  35. MyGraphicsView::MyGraphicsView(QWidget *parent):
  36.     QGraphicsView(parent)
  37. {
  38.     
  39.  
  40. }
  41.  
  42. MyGraphicsView::~MyGraphicsView()
  43. {
  44.  
  45. }
  46.  
  47.  
  48. void MyGraphicsView::dragEnterEvent(QDragEnterEvent *event)
  49. {
  50.     if(event->mimeData()->hasFormat("text/plain")){
  51.         event->acceptProposedAction();
  52.         qDebug() << "view dragEnterEvent";
  53.     }
  54.  
  55.         QGraphicsView::dragEnterEvent(event);
  56. }
  57.  
  58. void MyGraphicsView::dragMoveEvent(QDragMoveEvent *event)
  59. {
  60.     qDebug() << "view dragMoveEvent";
  61.     event->acceptProposedAction();
  62. }
  63.  
  64.  
  65.  
  66. void MyGraphicsView::dropEvent(QDropEvent *event)
  67. {
  68.     qDebug() << "view dropevent";
  69.     if (event->mimeData()->hasFormat("draglist"))
  70.     {
  71.         QByteArray itemData = event->mimeData()->data("draglist");
  72.         QString strText = itemData;
  73.         MyGraphicsScene *scene=(MyGraphicsScene*)this->scene();
  74.         QPoint po = event->pos();
  75.         qDebug() << "dropevent pos:"<< po.x() << po.y() ;
  76.         if (strText == "直线")
  77.         {
  78.             scene->createLine(mapToScene(event->pos()));
  79.         }
  80.         else if (strText == "矩形") 
  81.         {
  82.             scene->createRect(mapToScene(event->pos()));
  83.         }
  84.         else 
  85.         {
  86.             QDataStream dataStream(&itemData, QIODevice::ReadOnly);
  87.             QPixmap pixmap;
  88.             dataStream >> pixmap;
  89.             scene->createPixmap(mapToScene(event->pos()), pixmap);
  90.         }      
  91.         event->acceptProposedAction();
  92.     }
  93.     QGraphicsView::dropEvent(event);
  94. }
  95.  
  96. Widget::Widget(QWidget *parent) :
  97.     QWidget(parent),
  98.     ui(new Ui::Widget)
  99. {
  100.     ui->setupUi(this);
  101.  
  102.     QStringList list1;
  103.     list1 <<"直线" <<"矩形";
  104.     MyListWidget *listWidget1 = new MyListWidget(this);
  105.  
  106.     listWidget1->addItems(list1);
  107.     listWidget1->setIconSize(QSize(200,200));
  108.     listWidget1->setGeometry(100,150,300,200);
  109.     listWidget1->setDragEnabled(true);
  110.  
  111.     m_scene = new MyGraphicsScene();
  112.     m_scene->setSceneRect(QRectF(-300,-200,600,400));
  113.     m_view = new MyGraphicsView(this);
  114.     m_view->setScene(m_scene);
  115.     m_view->setGeometry(500,100,400,600);
  116.     m_view->setAcceptDrops(true);
  117. }

一般的应用：QListWidget控件发送拖拽，Qgraphicview接收。

发送

  1. #ifndef MYLISTWIDGET_H
  2. #define MYLISTWIDGET_H
  3.  
  4. #include <QObject>
  5. #include <QListWidget>
  6.  
  7. class MyListWidget:public QListWidget
  8. {
  9.     Q_OBJECT
  10. public:
  11.     MyListWidget(QWidget *parent=0);
  12.     ~MyListWidget();
  13.  
  14. protected:
  15.     void mouseMoveEvent(QMouseEvent *event) override;
  16.     void mousePressEvent(QMouseEvent *event) override;
  17.  
  18. private:
  19.     QPoint m_dragPosition; // 拖放起点
  20.     QListWidgetItem *m_dragItem; // 被拖放的item
  21. public:
  22.     QStringList m_strList;
  23. };
  24.  
  25. #endif // MYLISTWIDGET_H
  26.  
  27.  
  28. #include "mylistwidget.h"
  29. #include <QMouseEvent>
  30. #include <QListWidgetItem>
  31. #include <QDrag>
  32. #include <QApplication>
  33. #include <QMimeData>
  34. #include <QPainter>
  35. #include <QPixmap>
  36.  
  37. MyListWidget::MyListWidget(QWidget *parent):
  38.     QListWidget(parent)
  39. {
  40.  
  41. }
  42.  
  43. MyListWidget::~MyListWidget(){
  44.  
  45. }
  46.  
  47. void MyListWidget::mouseMoveEvent(QMouseEvent *event)
  48. {
  49.     if (!(event->buttons()&Qt::LeftButton))
  50.         return;
  51.     if ((event->pos() - m_dragPosition).manhattanLength() < QApplication::startDragDistance())
  52.         return;
  53.     if (!m_dragItem)
  54.         return;
  55.     QDrag *drag = new QDrag(this);
  56.     QMimeData *mimeData = new QMimeData;
  57.     QString strtext = currentItem()->text();
  58.     if (strtext.isEmpty())
  59.     {
  60.         int row = currentRow() - 2;
  61.         QByteArray encodedData;
  62.         QDir dir1;
  63.         QString strdir = dir1.currentPath();
  64.         QString strfile = strdir + "/svg/" + m_strList[row];
  65.         QDataStream stream(&encodedData, QIODevice::WriteOnly);
  66.         {
  67.             QPixmap pixmap(strfile);
  68.             stream << pixmap;
  69.         }
  70.         mimeData->setData("draglist", encodedData);
  71.     }
  72.     else
  73.     {
  74.         mimeData->setData("draglist", strtext.toUtf8());
  75.     }
  76.     drag->setMimeData(mimeData);
  77.  
  78.     drag->exec(Qt::CopyAction | Qt::MoveAction);
  79. }
  80.  
  81. void MyListWidget::mousePressEvent(QMouseEvent *event){
  82.     m_dragPosition=event->pos();
  83.     m_dragItem=this->itemAt(event->pos());
  84.  
  85.     //保持父类继承下来的按键行为
  86.     QListWidget::mousePressEvent(event);
  87. }

接收

  1. #ifndef MYGRAPHICSSCENE_H
  2. #define MYGRAPHICSSCENE_H
  3.  
  4. #include <QObject>
  5. #include <QGraphicsView>
  6. class MyGraphicsScene : public QGraphicsScene
  7. {
  8.     Q_OBJECT
  9. public:
  10.     MyGraphicsScene(QWidget *parent=0);
  11.     ~MyGraphicsScene();
  12.  
  13.     void createRect(const QPointF &pt);
  14.     void createLine(const QPointF &pt);
  15.     void createPixmap(const QPointF &pt, const QPixmap &pixmap);
  16. private:
  17.     QGraphicsScene *m_scene;
  18. };
  19.  
  20. #endif // MYGRAPHICSSCENE_H
  21.  
  22.  
  23.  
  24. #include "mygraphicsscene.h"
  25. #include <QDebug>
  26. #include <QMimeData>
  27. #include <QGraphicsSceneDragDropEvent>
  28. #include <QGraphicsLineItem>
  29. #include <QGraphicsRectItem>
  30. #include <QGraphicsScene>
  31. #include <QPen>
  32. #include "mygraphicslineitem.h"
  33. #include "mygraphicsrectitem.h"
  34.  
  35. #if _MSC_VER >=1600
  36.  
  37. #pragma execution_character_set("utf-8")
  38.  
  39. #endif
  40.  
  41. MyGraphicsScene::MyGraphicsScene(QWidget *parent):
  42.     QGraphicsScene(parent)
  43. {
  44.  
  45. }
  46.  
  47. MyGraphicsScene::~MyGraphicsScene()
  48. {
  49.  
  50. }
  51.  
  52. void MyGraphicsScene::createRect(const QPointF &pt)
  53. {
  54.     //MyGraphicsRectItem *item=new MyGraphicsRectItem;
  55.     QGraphicsRectItem *item = new QGraphicsRectItem();
  56.     item->setBrush(Qt::red);
  57.     item->setRect(0,0,20,30);
  58.     item->setPos(pt);
  59.     qDebug() << "createRect pos:" << pt.x() << pt.y();
  60. //    item->setFlags(QGraphicsItem::ItemIsSelectable|QGraphicsItem::ItemIsMovable);
  61.     addItem(item);
  62. }
  63.  
  64. void MyGraphicsScene::createLine(const QPointF &pt)
  65. {
  66.     MyGraphicsLineItem *item=new MyGraphicsLineItem;
  67.     item->setPos(pt);
  68.     item->setFlags(QGraphicsItem::ItemIsSelectable|QGraphicsItem::ItemIsMovable);
  69.     addItem(item);
  70. }
  71.  
  72. void MyGraphicsScene::createPixmap(const QPointF &pt, const QPixmap &pixmap)
  73. {
  74.     QGraphicsPixmapItem *item = new QGraphicsPixmapItem();
  75.     item->setPixmap(pixmap);
  76.     item->setPos(pt);
  77.     qDebug() << "createRect pos:" << pt.x() << pt.y();
  78.     //    item->setFlags(QGraphicsItem::ItemIsSelectable|QGraphicsItem::ItemIsMovable);
  79.     addItem(item);
  80. }
  1. #ifndef MYGRAPHICSVIEW_H
  2. #define MYGRAPHICSVIEW_H
  3.  
  4. #include <QObject>
  5. #include <QGraphicsView>
  6.  
  7. class MyGraphicsView : public QGraphicsView
  8. {
  9. public:
  10.     MyGraphicsView(QWidget *parent=0);
  11.     ~MyGraphicsView();
  12.  
  13. protected:
  14.     void dragEnterEvent(QDragEnterEvent *event);
  15.     void dragMoveEvent(QDragMoveEvent *event) ;
  16.     void dropEvent(QDropEvent *event);
  17.     void mouseMoveEvent(QMouseEvent *event);
  18.     void mousePressEvent(QMouseEvent *event);
  19.     void mouseReleaseEvent(QMouseEvent *event) ;
  20.  public:
  21.     bool m_blinedraw{false};
  22. private:
  23.     QPoint startpoint;
  24.     QPoint finishpoint;
  25. };
  26.  
  27. #endif // MYGRAPHICSVIEW_H
  28.  
  29.  
  30.  
  31. #include "mygraphicsview.h"
  32. #include "mygraphicsscene.h"
  33.  
  34. #include <QDragEnterEvent>
  35. #include <QMimeData>
  36. #include <QDebug>
  37. #include    <QMouseEvent>
  38. #include    <QPoint>
  39. #include <QGraphicsLineItem>
  40.  
  41. #if _MSC_VER >=1600
  42.  
  43. #pragma execution_character_set("utf-8")
  44.  
  45. #endif
  46.  
  47. MyGraphicsView::MyGraphicsView(QWidget *parent):
  48.     QGraphicsView(parent)
  49. {
  50.     startpoint.setX(0);
  51.     startpoint.setY(0);
  52.     finishpoint.setX(0);
  53.     finishpoint.setY(0);
  54.  
  55.  
  56. }
  57.  
  58. MyGraphicsView::~MyGraphicsView()
  59. {
  60.  
  61. }
  62.  
  63.  
  64. void MyGraphicsView::dragEnterEvent(QDragEnterEvent *event)
  65. {
  66.     if(event->mimeData()->hasFormat("text/plain")){
  67.         event->acceptProposedAction();
  68.         qDebug() << "view dragEnterEvent";
  69.     }
  70.  
  71.         QGraphicsView::dragEnterEvent(event);
  72. }
  73.  
  74. void MyGraphicsView::dragMoveEvent(QDragMoveEvent *event)
  75. {
  76.     qDebug() << "view dragMoveEvent";
  77.     event->acceptProposedAction();
  78. }
  79.  
  80.  
  81.  
  82. void MyGraphicsView::dropEvent(QDropEvent *event)
  83. {
  84.     qDebug() << "view dropevent";
  85.     if (event->mimeData()->hasFormat("draglist"))
  86.     {
  87.  
  88.         QByteArray itemData = event->mimeData()->data("draglist");
  89.         QString strText = itemData;
  90.         MyGraphicsScene *scene=(MyGraphicsScene*)this->scene();
  91.         QPoint po = event->pos();
  92.         qDebug() << "dropevent pos:"<< po.x() << po.y() ;
  93.         if (strText == "直线")
  94.         {
  95.             scene->createLine(mapToScene(event->pos()));
  96.         }
  97.         else if (strText == "矩形") 
  98.         {
  99.             scene->createRect(mapToScene(event->pos()));
  100.         }
  101.         else 
  102.         {
  103.             QDataStream dataStream(&itemData, QIODevice::ReadOnly);
  104.             QPixmap pixmap;
  105.             dataStream >> pixmap;
  106.             scene->createPixmap(mapToScene(event->pos()), pixmap);
  107.  
  108.         }
  109.         
  110.         event->acceptProposedAction();
  111.     }
  112.  
  113.     QGraphicsView::dropEvent(event);
  114. }
  115.  
  116. void MyGraphicsView::mouseMoveEvent(QMouseEvent *event)
  117. {
  118.  
  119.     QGraphicsView::mouseMoveEvent(event);
  120.     int a = 1;
  121. }
  122.  
  123. void MyGraphicsView::mousePressEvent(QMouseEvent *event)
  124. {
  125.     if (event->button()==Qt::LeftButton && m_blinedraw)
  126.     {
  127.         QPoint viewpos = event->pos();
  128.         QPointF scenepos = mapToScene(viewpos);
  129.         QGraphicsItem  *item=NULL;
  130.         item = scene()->itemAt(scenepos,transform());
  131.         if (item != nullptr) //有绘图项
  132.         {
  133.             startpoint = viewpos;
  134.         }
  135.     }
  136.     QGraphicsView::mousePressEvent(event);
  137.     int a = 1;
  138. }
  139.  
  140. void MyGraphicsView::mouseReleaseEvent(QMouseEvent *event)
  141. {
  142.     if (event->button()==Qt::LeftButton && m_blinedraw)
  143.     {
  144.         QPoint viewpos = event->pos();
  145.         QPointF scenepos = mapToScene(viewpos);
  146.         QGraphicsItem  *item=NULL;
  147.         item = scene()->itemAt(scenepos,transform());
  148.         if (item != nullptr && !(startpoint.x() == 0 && startpoint.y() == 0) ) //有绘图项
  149.         {
  150.             finishpoint = viewpos;
  151.             QLineF line(mapToScene(startpoint),scenepos);
  152.             QGraphicsLineItem *lineitem = new QGraphicsLineItem(line);
  153.             scene()->addItem(lineitem);
  154.             startpoint.setX(0);
  155.             startpoint.setY(0);
  156.             finishpoint.setX(0);
  157.             finishpoint.setY(0);
  158.  
  159.         }
  160.  
  161.     }
  162.     QGraphicsView::mouseReleaseEvent(event);
  163. }
  1. #ifndef MYGRAPHICSLINEITEM_H
  2. #define MYGRAPHICSLINEITEM_H
  3.  
  4. #include <QGraphicsItem>
  5.  
  6. class MyGraphicsLineItem : public QGraphicsItem
  7. {
  8. public:
  9.     MyGraphicsLineItem();
  10.     ~MyGraphicsLineItem();
  11.  
  12.     QRectF boundingRect()const;
  13.     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
  14. };
  15.  
  16. #endif // MYGRAPHICSLINEITEM_H
  17.  
  18.  
  19. #include "mygraphicslineitem.h"
  20. #include <QPainter>
  21. #include <QBrush>
  22.  
  23. MyGraphicsLineItem::MyGraphicsLineItem()
  24. {
  25.  
  26. }
  27.  
  28. MyGraphicsLineItem::~MyGraphicsLineItem()
  29. {
  30.  
  31. }
  32.  
  33. QRectF MyGraphicsLineItem::boundingRect() const
  34. {
  35.     qreal penWidth=1;
  36.     return QRectF(0-penWidth/2,0-penWidth/2,4+penWidth,80+penWidth);
  37. }
  38.  
  39. void MyGraphicsLineItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
  40. {
  41.     Q_UNUSED(option)
  42.     Q_UNUSED(widget)
  43.  
  44.     painter->setBrush(Qt::red);
  45.     painter->drawRect(0,0,4,80);
  46. }
  47.  

  1. #ifndef MYGRAPHICSRECTITEM_H
  2. #define MYGRAPHICSRECTITEM_H
  3.  
  4. #include <QGraphicsItem>
  5.  
  6. class MyGraphicsRectItem : public QGraphicsItem
  7. {
  8. public:
  9.     MyGraphicsRectItem();
  10.     ~MyGraphicsRectItem();
  11.  
  12.     QRectF boundingRect()const;
  13.     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
  14. };
  15.  
  16. #endif // MYGRAPHICSRECTITEM_H
  17.  
  18.  
  19. #include "mygraphicsrectitem.h"
  20. #include <QPainter>
  21. #include <QDebug>
  22. #include <QBrush>
  23.  
  24. MyGraphicsRectItem::MyGraphicsRectItem()
  25. {
  26.  
  27. }
  28.  
  29. MyGraphicsRectItem::~MyGraphicsRectItem()
  30. {
  31.  
  32. }
  33.  
  34. QRectF MyGraphicsRectItem::boundingRect() const
  35. {
  36.     qreal penWidth=1;
  37.     return QRectF(0-penWidth/2,0-penWidth/2,18+penWidth,56+penWidth);
  38. }
  39.  
  40. void MyGraphicsRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
  41. {
  42.     Q_UNUSED(option)
  43.     Q_UNUSED(widget)
  44.     painter->setBrush(Qt::red);
  45.     painter->drawRect(0,0,18,56);
  46. }
  1. #ifndef WIDGET_H
  2. #define WIDGET_H
  3.  
  4. #include <QWidget>
  5. #include <QtSvg>
  6.  
  7. namespace Ui {
  8. class Widget;
  9. }
  10.  
  11.  
  12. class MyGraphicsScene;
  13. class MyGraphicsView;
  14. class MyListWidget;
  15.  
  16.  
  17. class Widget : public QWidget
  18. {
  19.     Q_OBJECT
  20.  
  21. public:
  22.     explicit Widget(QWidget *parent = nullptr);
  23.     ~Widget();
  24.  
  25.    MyGraphicsScene * m_scene;
  26.    MyGraphicsView *m_view;
  27.  
  28.    MyListWidget *listWidget1;
  29.    
  30.  
  31.  
  32. private:
  33.     Ui::Widget *ui;
  34.  
  35. protected:
  36.     void paintEvent(QPaintEvent *event);
  37.  
  38.  
  39.     QSvgRenderer* svgRender;
  40. public slots:
  41.     void readbuttonslot();
  42.     void writebuttonslot();
  43.     void Linebuttonslot();
  44.     void Allreadbuttonslot();
  45.  
  46.  
  47. };
  48.  
  49. #endif // WIDGET_H
  50.  
  51.  
  52. #include "widget.h"
  53. #include "ui_widget.h"
  54. #include "mylistwidget.h"
  55.  
  56. #include "mygraphicsscene.h"
  57.  
  58. #include <QDebug>
  59. #include <QGraphicsItem>
  60. #include <QList>
  61. #include <mygraphicsview.h>
  62. #include "mysvgwidget.h"
  63.  
  64. #include <QPushButton>
  65.  
  66.  
  67.  
  68. #if _MSC_VER >=1600
  69.  
  70. #pragma execution_character_set("utf-8")
  71.  
  72. #endif
  73.  
  74.  
  75.  
  76.  
  77.  
  78.  
  79. Widget::Widget(QWidget *parent) :
  80.     QWidget(parent),
  81.     ui(new Ui::Widget)
  82. {
  83.     ui->setupUi(this);
  84.  
  85.     QStringList list1, list2;
  86.     list1 <<"直线" <<"矩形";
  87.     list2 <<"阿童木" <<"皮卡丘" <<"卡卡西" <<"奈落"<<"一休" << "黑猫警长" <<"兔八哥"<<"三毛"<<"舒克"<<"贝塔";;
  88.     listWidget1 = new MyListWidget(this);
  89.     
  90.  
  91.     listWidget1->addItems(list1);
  92.     listWidget1->setIconSize(QSize(32,32));
  93.     listWidget1->setGeometry(100,100,500,300);
  94.     listWidget1->setDragEnabled(true);
  95.  
  96.  
  97.     m_scene = new MyGraphicsScene();
  98.     m_scene->setSceneRect(QRectF(-300,-200,600,400));
  99.     m_view = new MyGraphicsView(this);
  100.     m_view->setScene(m_scene);
  101.     m_view->setGeometry(500,100,400,600);
  102.     m_view->setAcceptDrops(true);
  103. //    m_view->show();
  104.  
  105.     QString strPath = "arrow.svg";
  106.     svgRender = new QSvgRenderer(this);
  107.     bool ret = svgRender->load(QString("G:/opencode/qt/msvc/test/drag/arrow.svg"));
  108.     int a = 1;
  109.  
  110.     MySvgWidget *psvgwidget;
  111.     psvgwidget = new MySvgWidget(this);
  112.     psvgwidget->setGeometry(200,0,200,200);
  113.     psvgwidget->show();
  114.     psvgwidget->load(QString("G:/opencode/qt/msvc/test/drag/arrow.svg"));
  115.  
  116.  
  117.  
  118.     QPushButton *pReadbutton = new QPushButton(tr("加载svg"),this);
  119.     pReadbutton->setGeometry(10,height()-50,60,40);
  120.     connect(pReadbutton,SIGNAL(clicked()),this,SLOT(readbuttonslot()));
  121.  
  122.     QPushButton *pWritebutton = new QPushButton(tr("保存svg"),this);
  123.     pWritebutton->setGeometry(100,height()-50,60,40);
  124.     connect(pWritebutton,SIGNAL(clicked()),this,SLOT(writebuttonslot()));
  125.  
  126.     QPushButton *pLinebutton = new QPushButton(tr("连线"),this);
  127.     pLinebutton->setGeometry(200,height()-50,60,40);
  128.     connect(pLinebutton,SIGNAL(clicked()),this,SLOT(Linebuttonslot()));
  129.  
  130.     QPushButton *pAllReadbutton = new QPushButton(tr("一键加载svg"), this);
  131.     pAllReadbutton->setGeometry(280, height() - 50, 60, 40);
  132.     connect(pAllReadbutton, SIGNAL(clicked()), this, SLOT(Allreadbuttonslot()));
  133.  
  134.  
  135.  
  136. }
  137.  
  138. Widget::~Widget()
  139. {
  140.     delete ui;
  141. }
  142.  
  143. void Widget::paintEvent(QPaintEvent *event)
  144. {
  145.     QPainter p(this);
  146.     svgRender->render(&p,QRectF(0,0,100,100));
  147. }
  148.  
  149. void Widget::readbuttonslot()
  150. {
  151.  
  152.     QString filePath = QFileDialog::getOpenFileName(0, "打开文件", ".", "SVG(*.svg)");
  153.     if(filePath.isEmpty())
  154.     {
  155.         return;
  156.     }
  157.  
  158.     QSvgRenderer *renderer = new QSvgRenderer(filePath);
  159.     QGraphicsSvgItem *blackSvgItem = new QGraphicsSvgItem();
  160.     blackSvgItem->setSharedRenderer(renderer);
  161.     m_scene->addItem(blackSvgItem);
  162.     blackSvgItem->setFlags (QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
  163. }
  164.  
  165. void Widget::writebuttonslot()
  166. {
  167.     QString filePath = QFileDialog::getSaveFileName(0, "保存文件", ".", "SVG(*.svg)");
  168.     if(filePath.isEmpty())
  169.     {
  170.         return;
  171.     }
  172.     QSvgGenerator svgGenerator;
  173.     svgGenerator.setFileName(filePath);
  174.     svgGenerator.setSize(QSize(rect().width(), rect().height()));
  175.     svgGenerator.setViewBox(rect()); svgGenerator.setTitle("测试QSvgGenerator");
  176.     svgGenerator.setDescription("另存为绘制测试");
  177.     QPainter painter;
  178.     painter.begin(&svgGenerator);
  179.     painter.setPen(Qt::red);
  180.     painter.drawLine(QPointF(20,20),QPointF(100,100));
  181.     painter.drawText(rect(), "测试Svg");
  182.     QPixmap pixmap = this->grab(QRect(0, 0, 1000, 800));
  183.     painter.drawPixmap(10,10,pixmap);
  184.     painter.end();
  185.  
  186.  
  187. }
  188.  
  189. void Widget::Linebuttonslot()
  190. {
  191.     if(m_view)
  192.     {
  193.         m_view->m_blinedraw = true;
  194.     }
  195.  
  196. }
  197.  
  198. void Widget::Allreadbuttonslot()
  199. {
  200.     listWidget1->m_strList.clear();
  201.     QDir dir1;
  202.     QString strdir = dir1.currentPath();
  203.     strdir += "/svg";
  204.     QDir dir(strdir);
  205.     listWidget1->m_strList = dir.entryList(QDir::Files);
  206.     int num = listWidget1->m_strList.size();
  207.     QString strfile;
  208.     for (int i = 0; i < num; ++i)
  209.     {
  210.         strfile = strdir + "/" +listWidget1->m_strList[i];
  211.         QListWidgetItem *item = new QListWidgetItem(QIcon(strfile),"");
  212.         listWidget1->addItem(item);
  213.     }
  214.     
  215. }
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