qt创建的图片显示控件dll，通过其他程序调用的实现

#include "CustomGraphicsView.h" #include <QMutexLocker> #include <QLayout> #include <QWheelEvent> #include "CustomImageItem.h" #include <QRandomGenerator> #define ZOOMMAX 50 //最大放大倍数 #define ZOOMMIN 0.02 //最小缩小倍数 CustomGraphicsView::CustomGraphicsView(QWidget *parent) : QGraphicsView(parent) , m_pScene(Q_NULLPTR) , m_pImageItem(Q_NULLPTR) , m_pPosInfoWidget(Q_NULLPTR) , m_pPosInfoLabel(Q_NULLPTR) { this->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff); this->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff); this->setRenderHint(QPainter::Antialiasing); this->setTransformationAnchor(QGraphicsView::AnchorViewCenter); this->setViewportUpdateMode(QGraphicsView::FullViewportUpdate); this->setSceneRect(INT_MIN/2, INT_MIN/2, INT_MAX, INT_MAX); this->setTransformationAnchor(QGraphicsView::AnchorUnderMouse); this->setResizeAnchor(QGraphicsView::AnchorUnderMouse); this->setAttribute(Qt::WA_TranslucentBackground); //this->setStyleSheet(QString::fromUtf8("#widget_2{border:3px solid red}")); //this->setStyleSheet(QString::fromUtf8("border:0px solid black")); setBackground(true,false); centerOn(0, 0); if(false == InitWidget()) { throw std::bad_alloc(); } } CustomGraphicsView::~CustomGraphicsView() { } bool CustomGraphicsView::InitWidget() { //创建变量对象 m_pScene = new QGraphicsScene(this); m_pImageItem = new CustomImageItem(this); m_pImageItem->setAcceptHoverEvents(true); m_pImageItem->setFlags(QGraphicsItem::ItemIsSelectable | QGraphicsItem::ItemIsMovable); this->setScene(m_pScene); m_pScene->addItem(m_pImageItem); m_pPosInfoLabel = new QLabel(this); m_pPosInfoWidget = new QWidget(this); //在视觉窗口下方显示鼠标坐标以及图像的灰度值 m_pPosInfoLabel->setStyleSheet("color:rgb(200,255,200); " "background-color:rgba(50,50,50,50); " "font: Microsoft YaHei;" "font-size: 12px;"); m_pPosInfoLabel->setText(" W:0,H:0 | X:0,Y:0 | R:0,G:0,B:0"); //显示区域窗口 m_pPosInfoWidget->setFixedHeight(20); m_pPosInfoWidget->setGeometry(0, this->height() - 20, this->width(), 20); m_pPosInfoWidget->setStyleSheet("background-color:rgba(0,0,0,0);"); QHBoxLayout* pInfoLayout = new QHBoxLayout(); pInfoLayout->setSpacing(0); pInfoLayout->setContentsMargins(1,1,1,1); pInfoLayout->addWidget(m_pPosInfoLabel); // pInfoLayout->addStretch(); m_pPosInfoWidget->setLayout(pInfoLayout); m_pPosInfoWidget->setAttribute(Qt::WA_TransparentForMouseEvents); //初始化信号槽 connect(m_pImageItem, &CustomImageItem::RGBValue, this, [&](QString InfoVal) { m_pPosInfoLabel->setText(InfoVal); }); return true; } //为视觉窗口设置图像，是一个公共对外接口 void CustomGraphicsView::SetImage(const QImage &image) { static QMutex mutex; QMutexLocker locker(&mutex); m_qImage = image.copy(); m_Image = QPixmap::fromImage(image); m_pImageItem->w = m_Image.width(); m_pImageItem->h = m_Image.height(); m_pImageItem->setPixmap(m_Image); fitFrame(); onCenter(); show(); } //重写鼠标滚轮滚动的事件函数 //主要依赖于Zoom()方法 void CustomGraphicsView::wheelEvent(QWheelEvent *event) { //滚轮的滚动量 QPoint scrollAmount = event->angleDelta(); if ((scrollAmount.y() > 0) && (m_dZoomValue >= ZOOMMAX)) //最大放大到原始图像的50倍 { return; } else if ((scrollAmount.y() < 0) && (m_dZoomValue <= ZOOMMIN))//最小缩小到原始图像的50倍 { return; } // 正值表示滚轮远离使用者,为放大;负值表示朝向使用者,为缩小 scrollAmount.y() > 0 ? onZoom(1.2f) : onZoom(0.8f); } // //在视觉窗口上双击鼠标左键，会有图像居中效果，主要依赖于onCenter()方法。 // void CustomGraphicsView::mouseDoubleClickEvent(QMouseEvent *event) // { // if(event->button() == Qt::LeftButton) // { // //自适应图像大小至视觉窗口的大小 // fitFrame(); // //居中显示 // onCenter(); // } // QGraphicsView::mouseDoubleClickEvent(event); // } //绘制函数，用于视觉窗口背景绘制 void CustomGraphicsView::paintEvent(QPaintEvent* event) { QPainter paint(this->viewport()); //绘制背景 paint.drawTiledPixmap(QRect(QPoint(0, 0), QPoint(this->width(), this->height())), m_tilePixmap); QGraphicsView::paintEvent(event); //qDebug()<<QRandomGenerator::global()->bounded(100.0); //生成一个0和10.123之间的浮点数 } //当窗口尺寸发生变化时，实时更新视觉窗口位置 void CustomGraphicsView::resizeEvent(QResizeEvent *event) { fitFrame(); onCenter(); m_pPosInfoWidget->setGeometry(0, this->height() - 20, this->width(), 20); QGraphicsView::resizeEvent(event); } //视图居中 void CustomGraphicsView::onCenter() { //调用QGraphicsView自带的方法centerOn，使视觉窗口的中心位于图像元素的中心点 //并设置m_pImageItem的坐标，使其也位于中心点 this->centerOn(0,0); m_pImageItem->setPos(-m_pImageItem->pixmap().width()/2,-m_pImageItem->pixmap().height()/2); } void CustomGraphicsView::onZoom(float scaleFactor) { //记录下当前相对于图像原图的缩放比例，可以记录下当前图像真实放大缩小了多少倍 //可以借此来限制图像的最大或最小缩放比例 m_dZoomValue *= scaleFactor; //调用视图类QGraphicsView自带的scale缩放方法，来对视图进行缩放，实现放大缩小的功能 //缩放的同时，视图里的所有元素也会进行缩放，也就达到了视觉窗口放大缩小的效果 this->scale(scaleFactor, scaleFactor); } void CustomGraphicsView::FitImage() { qDebug()<<"触发右键自适应图像"; //自适应图像大小至视觉窗口的大小 fitFrame(); //居中显示 onCenter(); } //图片自适应方法，根据图像原始尺寸和当前视觉窗口的大小计算出应缩放的尺寸，再根据已经缩放的比例计算还差的缩放比例， //补齐应缩放的比例，使得图像和视觉窗口大小相适配 void CustomGraphicsView::fitFrame() { if (this->width() < 1 || m_Image.width() < 1) return; //计算缩放比例 double winWidth = this->width(); double winHeight = this->height(); double ScaleWidth = (m_Image.width() + 1) / winWidth; double ScaleHeight = (m_Image.height() + 1) / winHeight; double s_temp = ScaleWidth >= ScaleHeight ? 1 / ScaleWidth : 1 / ScaleHeight; double scale = s_temp / m_dZoomValue; if ((scale >= ZOOMMAX) || (scale <= ZOOMMIN)) //最大放大到原始图像的50倍 { return; } onZoom(scale); m_dZoomValue = s_temp; } //设置视觉窗口背景为棋盘格样式 void CustomGraphicsView::setBackground(bool enabled, bool invertColor) { if (enabled) { m_tilePixmap.fill(invertColor ? QColor(220, 220, 220) : QColor(35, 35, 35)); QPainter tilePainter(&m_tilePixmap); constexpr QColor color(50, 50, 50, 255); constexpr QColor invertedColor(210, 210, 210, 255); tilePainter.fillRect(0, 0, 18, 18, invertColor ? invertedColor : color); tilePainter.fillRect(18, 18, 18, 18, invertColor ? invertedColor : color); tilePainter.end(); //当取消注释时，视觉窗口背景格会跟随图像一起缩放 //setBackgroundBrush(m_tilePixmap); } else { //setBackgroundBrush(Qt::transparent); } }