可以加上鼠标点击移动图片操作吗-Go服务器开发

当然可以！要实现鼠标点击和拖动移动图片的功能，可以重载 mousePressEvent、mouseMoveEvent 和 mouseReleaseEvent 方法来处理鼠标事件。下面是更新后的代码示例：

更新后的示例代码

#include <QApplication>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsPixmapItem>
#include <QWheelEvent>
#include <QKeyEvent>

class ImageView : public QGraphicsView {
    Q_OBJECT

public:
    ImageView(QWidget *parent = nullptr) : QGraphicsView(parent), scaleFactor(1.0), dragging(false) {
        scene = new QGraphicsScene(this);
        setScene(scene);

        // 加载并显示图片
        QPixmap pixmap("path/to/your/image.jpg");
        imageItem = scene->addPixmap(pixmap);
        
        // 设置视图背景颜色（可选）
        setBackgroundBrush(Qt::black);
        
        // 启用鼠标跟踪
        setMouseTracking(true);
    }

protected:
    void wheelEvent(QWheelEvent *event) override {
        // 缩放处理
        if (event->angleDelta().y() > 0)
            scaleImage(1.2); // 放大
        else
            scaleImage(1 / 1.2); // 缩小
    }

    void keyPressEvent(QKeyEvent *event) override {
        switch (event->key()) {
            case Qt::Key_Left:
                translateImage(-10, 0); // 向左平移
                break;
            case Qt::Key_Right:
                translateImage(10, 0); // 向右平移
                break;
            case Qt::Key_Up:
                translateImage(0, -10); // 向上平移
                break;
            case Qt::Key_Down:
                translateImage(0, 10); // 向下平移
                break;
            default:
                QGraphicsView::keyPressEvent(event);
        }
    }

    void mousePressEvent(QMouseEvent *event) override {
        if (event->button() == Qt::LeftButton) {
            lastPos = event->pos();
            dragging = true; // 开始拖动
        }
    }

    void mouseMoveEvent(QMouseEvent *event) override {
        if (dragging && event->buttons() & Qt::LeftButton) {
            QPointF delta = mapToScene(event->pos()) - mapToScene(lastPos);
            imageItem->moveBy(delta.x(), delta.y());
            lastPos = event->pos(); // 更新最后位置
        }
    }

    void mouseReleaseEvent(QMouseEvent *event) override {
        if (event->button() == Qt::LeftButton) {
            dragging = false; // 停止拖动
        }
    }

private:
    QGraphicsScene *scene;
    QGraphicsPixmapItem *imageItem;
    
    qreal scaleFactor;
    
    bool dragging;          // 拖动状态标志
    QPoint lastPos;         // 上一个鼠标位置

    void scaleImage(qreal factor) {
        scaleFactor *= factor;

        // 确保不会无穷缩放，限制最大和最小值。
        if (scaleFactor < 0.1) scaleFactor = 0.1; 
        if (scaleFactor > 5.0) scaleFactor = 5.0; 

        imageItem->setScale(scaleFactor);
    }

    void translateImage(qreal dx, qreal dy) {
         QPointF pos = imageItem->pos();
         imageItem->setPos(pos.x() + dx, pos.y() + dy);
     }
};

int main(int argc, char *argv[]) {
   QApplication app(argc, argv);

   ImageView view;
   view.setWindowTitle("Image Viewer with Zoom and Pan");
   view.resize(800, 600);
   view.show();

   return app.exec();
}

#include "main.moc"