（GraphicsView，QPainter，QGraphicsRectItem）QT用鼠标绘制矩形

#include "DrawROI.h" DrawROI::DrawROI(QGraphicsView* GraphicsView, QObject*parent) : QObject(parent) { m_graphicsView = GraphicsView; m_isDrawMultipROIS = false; isROIBeginChange = false; m_currentROIIndex = 0; initViewer(); } DrawROI::~DrawROI() { } void DrawROI::drawROI() { if (m_pixmap.isNull()) return; for (int i = 0; i < m_rois.size(); i++) { QPen pen; pen.setColor(Qt::red); pen.setWidth(EDGE_WIDTH); QFont font; font.setPixelSize(12); //设置字体大小 QPainter painter(m_graphicsView->viewport()); painter.begin(m_graphicsView); //绘画开始 painter.setBrush(QBrush(QColor(0, 0, 200, 20))); //画刷填充框内颜色 painter.setPen(pen); painter.setFont(font); //roi图元坐标转视图坐标,因为画roi是按视图坐标画的 QPoint roiViewPoint = m_graphicsView->mapFromScene(m_rois[i].x(), m_rois[i].y()); QRect roi(roiViewPoint.x(), roiViewPoint.y(), m_rois[i].width(), m_rois[i].height()); //QPixmap rawImg = m_pixmap.scaled(m_graphicsView->size(), Qt::KeepAspectRatio); // QPixmap rawImg = m_pixmap; QString strPoint = QString("X:%0, Y:%1").arg(m_rois[i].x()).arg(m_rois[i].y()); //roi位置信息 QString strSize = QString("W:%0, H:%1").arg(m_rois[i].width()).arg(m_rois[i].height()); //roi大小信息 std::map<int, QRect>::iterator it = m_rois.begin(); for (int j = 0; j < i; j++) { it++; } QString roiIndex = QString("#roi:%0").arg(it->first); //roi序号 painter.drawText(roi.topLeft().x(), roi.topLeft().y() - 5, strSize); painter.drawText(roi.topLeft().x(), roi.topLeft().y() - 18, strPoint); painter.drawText(roi.topLeft().x(), roi.topLeft().y() - 31, roiIndex); // painter.drawRect(m_roiRect); painter.drawRect(roi); if (m_rois[i].width() != 0 && m_rois[i].height() != 0) { //绘制中间十字架 QPen dashPen(Qt::white); dashPen.setWidth(MIDDLELINE_WIDTH); dashPen.setStyle(Qt::DashDotLine); painter.setPen(dashPen); //从上往下画线，获取roi的y坐标始终为线宽的上边 painter.drawLine(roi.topLeft().x() + m_rois[i].width() / 2, roi.topLeft().y() + EDGE_WIDTH, roi.bottomRight().x() - m_rois[i].width() / 2, roi.bottomRight().y()); //从左往右画线， 获取roi的x坐标始终是线宽的左边 painter.drawLine(roi.topLeft().x() + EDGE_WIDTH, roi.topLeft().y() + m_rois[i].height() / 2, roi.bottomRight().x(), roi.bottomRight().y() - m_rois[i].height() / 2); //绘制边缘九个点 //painter.setBrush(Qt::green); //pen.setWidth(0); //painter.setPen(pen); //painter.drawRect(m_roiRect.topLeft().x(), m_roiRect.topLeft().y(), POINT_WIDTH, POINT_HEIGHT); //左上角 //painter.drawRect(m_roiRect.topLeft().x(), m_roiRect.topLeft().y() + m_roiRect.height() / 2 - POINT_HEIGHT / 2, POINT_WIDTH, POINT_HEIGHT); //左边中心点 //painter.drawRect(m_roiRect.bottomLeft().x(), m_roiRect.bottomLeft().y() - POINT_HEIGHT, POINT_WIDTH, POINT_HEIGHT); //左下角 //painter.drawRect(m_roiRect.topLeft().x() + m_roiRect.width() / 2 - POINT_WIDTH / 2, m_roiRect.topLeft().y(), POINT_WIDTH, POINT_HEIGHT); //顶部中心 //painter.drawRect(m_roiRect.topLeft().x() + m_roiRect.width() / 2 - POINT_WIDTH / 2, m_roiRect.topLeft().y() + m_roiRect.height() / 2 - POINT_HEIGHT / 2, POINT_WIDTH, POINT_HEIGHT); //中心点 //painter.drawRect(m_roiRect.bottomLeft().x() + m_roiRect.width() / 2 - POINT_WIDTH / 2, m_roiRect.bottomLeft().y() - POINT_HEIGHT, POINT_WIDTH, POINT_HEIGHT); //底部中心点 //painter.drawRect(m_roiRect.topRight().x() - POINT_WIDTH, m_roiRect.topRight().y(), POINT_WIDTH, POINT_HEIGHT); //右上角 //painter.drawRect(m_roiRect.topRight().x() - POINT_WIDTH, m_roiRect.topRight().y() + m_roiRect.height() / 2 - POINT_HEIGHT / 2, POINT_WIDTH, POINT_HEIGHT); //右边中心点 //painter.drawRect(m_roiRect.bottomRight().x() - POINT_WIDTH, m_roiRect.bottomRight().y() - POINT_HEIGHT, POINT_WIDTH, POINT_HEIGHT); //右下角点 } //绘画结束 painter.end(); m_graphicsView->viewport()->update(); } } void DrawROI::changeROIBegin(const QPoint& point) { //场景坐标 QPointF fScenePoint = m_graphicsView->mapToScene(point); //图形项坐标 QGraphicsItem* pItem = m_graphicsView->scene()->itemAt(fScenePoint, QTransform()); if (NULL == pItem) { isBeginGraw = false; return; } isBeginGraw = true; QPointF fItemPoint = pItem->mapFromScene(fScenePoint); //获取图形项坐标 QPoint itemPoint(fItemPoint.x(), fItemPoint.y()); EmDirection dir = region(itemPoint); //获取鼠标当前的坐标在ROI什么位置 m_currentDir = dir; isROIBeginChange = true; if (dir == DIR_MIDDLE) { //鼠标在矩形中心位置 m_graphicsView->setCursor(Qt::ClosedHandCursor); m_moveStartPoint.setX(itemPoint.x()); m_moveStartPoint.setY(itemPoint.y()); m_bMovedPressed = true; } else if (dir == DIR_NONE) { //鼠标在矩形外部 m_graphicsView->setCursor(Qt::ArrowCursor); m_bPainterPressed = true; m_paintStartPoint.setX(itemPoint.x()); m_paintStartPoint.setY(itemPoint.y()); m_currentROIIndex = m_rois.size(); //更新roi序号 } else { //鼠标在矩形边缘 m_moveStartPoint.setX(itemPoint.x()); m_moveStartPoint.setY(itemPoint.y()); m_bScalePressed = true; m_emCurDir = dir; } } void DrawROI::changeROIInProgress(const QPoint& point) { if (!isBeginGraw) return; QPointF fScenePoint = m_graphicsView->mapToScene(point); //图形项坐标 QGraphicsItem* pItem = m_graphicsView->scene()->itemAt(fScenePoint, QTransform()); QPoint itemPoint; if (pItem != NULL) { QPointF fItemPoint = pItem->mapFromScene(fScenePoint); //获取图形项坐标 QPoint item(fItemPoint.x(), fItemPoint.y()); itemPoint = item; } else { //绘制roi超过图像边界进行处理 if (fScenePoint.x() < 0 && fScenePoint.y() < 0) { QPoint item(0, 0); itemPoint = item; } else if (fScenePoint.x() < 0) { QPoint item(0, fScenePoint.y()); itemPoint = item; } else if (fScenePoint.y() < 0) { QPoint item(fScenePoint.x(), 0); itemPoint = item; } else if (fScenePoint.x() >= m_pixmap.width() && fScenePoint.y() >= m_pixmap.height()) { QPoint item(m_pixmap.width() - 1, m_pixmap.height() - 1); itemPoint = item; } else if (fScenePoint.x() >= m_pixmap.width()) { QPoint item(m_pixmap.width() - 1, fScenePoint.y()); itemPoint = item; } else if (fScenePoint.y() >= m_pixmap.height()) { QPoint item(fScenePoint.x(), m_pixmap.height() - 1); itemPoint = item; } } if (m_bPainterPressed) { //正在绘制状态 paintRect(itemPoint); } else if (m_bMovedPressed) { //判断拖动roi是否超过图像边界 if ((m_rois[m_currentROIIndex].x() <= 0 && m_rois[m_currentROIIndex].y() <= 0)) { m_rois[m_currentROIIndex].setX(0); m_rois[m_currentROIIndex].setY(0); } else if ((m_rois[m_currentROIIndex].x() <= 0)) { m_rois[m_currentROIIndex].setX(0); } else if ((m_rois[m_currentROIIndex].y() <= 0)) { m_rois[m_currentROIIndex].setY(0);