Qdialog无边框且可以拖拽代码如何实现

可以使用以下代码实现：

class CustomDialog : public QDialog
{
public:
    CustomDialog(QWidget *parent = nullptr) : QDialog(parent)
    {
        setWindowFlags(Qt::FramelessWindowHint | Qt::WindowSystemMenuHint);
    }

protected:
    void mousePressEvent(QMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton)
        {
            m_dragging = true;
            m_dragPosition = event->globalPos() - frameGeometry().topLeft();
            event->accept();
        }
    }

    void mouseMoveEvent(QMouseEvent *event) override
    {
        if (m_dragging && (event->buttons() & Qt::LeftButton))
        {
            move(event->globalPos() - m_dragPosition);
            event->accept();
        }
    }

    void mouseReleaseEvent(QMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton)
        {
            m_dragging = false;
            event->accept();
        }
    }

private:
    bool m_dragging = false;
    QPoint m_dragPosition;
};

这个类继承自 QDialog，重写了鼠标事件的处理函数，实现了无边框且可以拖拽的功能。