c – 垂直QLabel,还是等价的？

解决方法

#ifndef VERTICALLABEL_H
#define VERTICALLABEL_H

#include <QLabel>

class VerticalLabel : public QLabel
{
    Q_OBjeCT

public:
    explicit VerticalLabel(QWidget *parent=0);
    explicit VerticalLabel(const QString &text,QWidget *parent=0);

protected:
    void paintEvent(QPaintEvent*);
    QSize sizeHint() const ;
    QSize minimumSizeHint() const;
};

#endif // VERTICALLABEL_H

/// CPP

#include "verticallabel.h"

#include <QPainter>

VerticalLabel::VerticalLabel(QWidget *parent)
    : QLabel(parent)
{

}

VerticalLabel::VerticalLabel(const QString &text,QWidget *parent)
: QLabel(text,parent)
{
}

void VerticalLabel::paintEvent(QPaintEvent*)
{
    QPainter painter(this);
    painter.setPen(Qt::black);
    painter.setBrush(Qt::Dense1Pattern);

    painter.rotate(90);

    painter.drawText(0,text());
}

QSize VerticalLabel::minimumSizeHint() const
{
    QSize s = QLabel::minimumSizeHint();
    return QSize(s.height(),s.width());
}

QSize VerticalLabel::sizeHint() const
{
    QSize s = QLabel::sizeHint();
    return QSize(s.height(),s.width());
}