qt拖拽事件重写

1.qt中的拖拽事件步骤

1设置接受拖拽
2重写事件就可以了
3其他的控件如何要可以套模板

2.例子

#include <QGroupBox>
#include <QObject>
#include <QDragEnterEvent>
#include <QFileInfo>
#include <QMimeData>

//重写，指出拖拽指定的文件进来,可以自己命名什么文件可以拖进来

class DGroupBox : public QGroupBox
{
    Q_OBJECT
public:
    DGroupBox(){
        setAcceptDrops(true);
    }
    
protected:
    void dragEnterEvent(QDragEnterEvent *event) override
    {
        QList<QUrl> urls = event->mimeData()->urls();
        bool acceptDrop = false;
        for (const QUrl &url : urls) {
            QString filePath = url.toLocalFile();
            //if (filePath.endsWith(".txt", Qt::CaseInsensitive))
            if(QFileInfo(filePath).fileName() == m_acceptFileName)
            {
                acceptDrop = true;
                event->setDropAction(Qt::CopyAction);
                event->accept();
                break;
            }
        }
        if (!acceptDrop) {
            event->setDropAction(Qt::IgnoreAction);
            event->ignore();
        }
    }
    
    void dragMoveEvent(QDragMoveEvent *event) override
    {
        switch (event->dropAction()) {
        case Qt::CopyAction:
            event->accept();
            setCursor(Qt::CursorShape::DragCopyCursor);
            break;
        default:
            event->ignore();
            setCursor(Qt::ForbiddenCursor);
            break;
        }
    }
    
    void dropEvent(QDropEvent *event) override
    {
        QList<QUrl> urls = event->mimeData()->urls();
        if (!urls.isEmpty()) {
            for (const QUrl &url : urls) {
                QString filePath = url.toLocalFile();
                //if (filePath.endsWith(".txt", Qt::CaseInsensitive))
                if(QFileInfo(filePath).fileName() == m_acceptFileName)
                {
                    // 将文件路径设置为QLabel的文本
                    emit accpetFile(filePath);
                }
            }
        }
        event->acceptProposedAction();
    }
signals:
    void accpetFile(QString filePath);
    
public:
    void setAcceptFileName(QString name){m_acceptFileName = name;}
private:
    QString m_acceptFileName = "encrypted_data.dat";
    
};

#endif // DGROUPBOX_H
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