Qt 图片交互-鼠标滚轮放缩、拖拽、选点

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资源介绍:

Qt 图片交互——鼠标滚轮放缩、拖拽、选点（工程源代码，编写的库方便使用，包含demo）演示视频：https://www.bilibili.com/video/BV1yv411P7hJ/

#include "hi_graphicsview.h" #include #include "hi_imagebox.h" HI_GraphicsView::HI_GraphicsView(QWidget *parent): QGraphicsView(parent), m_isTranslate(false), m_scene(new QGraphicsScene()), m_imageItem(new QGraphicsPixmapItem()) { m_scene->addItem(m_imageItem); setScene(m_scene); setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff); setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff); setRenderHint(QPainter::Antialiasing); setSceneRect(INT_MIN/2, INT_MIN/2, INT_MAX, INT_MAX); setTransformationAnchor(QGraphicsView::AnchorViewCenter); centerOn(0, 0); } HI_GraphicsView::~HI_GraphicsView() { m_scene->deleteLater(); delete m_imageItem; } void HI_GraphicsView::SetImage(const QImage &image) { m_imageItem->setPixmap(QPixmap::fromImage(image)); QPoint newCenter(image.width() / 2 ,image.height()/2); //设置scene中心到图像中点 centerOn(newCenter); show(); } void HI_GraphicsView::wheelEvent(QWheelEvent *event) { // 滚轮的滚动量 QPoint scrollAmount = event->angleDelta(); // 正值表示滚轮远离使用者放大负值表示朝向使用者缩小 scrollAmount.y() > 0 ? ZoomIn() : ZoomOut(); } void HI_GraphicsView::mouseMoveEvent(QMouseEvent *event) { if(m_isTranslate) { //获取 QPointF mouseDelta = event->pos()-m_lastMousePos; Translate(mouseDelta); } m_lastMousePos = event->pos(); QGraphicsView::mouseMoveEvent(event); } void HI_GraphicsView::mousePressEvent(QMouseEvent *event) { if(event->button() == Qt::LeftButton) { m_isTranslate = true; m_lastMousePos = event->pos(); } else if(event->button()==Qt::RightButton) { QPointF point = mapToScene(event->pos()); //只有点击图片时才发送 if (scene()->itemAt(point, transform()) != NULL) { emit m_imageBox->ImageClick(point.x(),point.y()); } } QGraphicsView::mousePressEvent(event); } void HI_GraphicsView::mouseReleaseEvent(QMouseEvent *event) { if (event->button() == Qt::LeftButton) m_isTranslate = false; QGraphicsView::mouseReleaseEvent(event); } void HI_GraphicsView::mouseDoubleClickEvent(QMouseEvent *event) { centerOn(m_imageItem->pixmap().width()/2,m_imageItem->pixmap().height()/2); QGraphicsView::mouseDoubleClickEvent(event); } void HI_GraphicsView::ZoomIn() { Zoom(1.1); } void HI_GraphicsView::ZoomOut() { Zoom(0.9); } void HI_GraphicsView::Zoom(float scaleFactor) { // 防止过小或过大 qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width(); if (factor < 0.07 || factor > 100) return; scale(scaleFactor, scaleFactor); } void HI_GraphicsView::Translate(QPointF delta) { int w = viewport()->rect().width(); int h = viewport()->rect().height(); QPoint newCenter(w / 2. - delta.x()+0.5, h / 2. - delta.y()+0.5); centerOn(mapToScene(newCenter)); }

资源文件列表:

Qt图片交互.zip 大约有13个文件

.gitignore 814B
HI_ImageBox.pro 996B
HI_ImageBox_Demo/
HI_ImageBox_Demo/.gitignore 814B
HI_ImageBox_Demo/HI_ImageBox_Demo.pro 1.29KB
HI_ImageBox_Demo/main.cpp 183B
HI_ImageBox_Demo/mainwindow.cpp 765B
HI_ImageBox_Demo/mainwindow.h 457B
HI_ImageBox_Demo/mainwindow.ui 1.23KB
hi_graphicsview.cpp 3.08KB
hi_graphicsview.h 1.04KB
hi_imagebox.cpp 804B
hi_imagebox.h 1.56KB