c++qtablewidget不显示行号

您可以通过以下两种方法在C++的QTableWidget中显示行号：
1.使用QTableWidget的setVerticalHeaderLabels()方法设置垂直表头标签，标签内容为行号。示例代码如下：

// 设置行数和列数
int rowCount = 5;
int columnCount = 3;
ui->tableWidget->setRowCount(rowCount);
ui->tableWidget->setColumnCount(columnCount);

// 设置垂直表头标签
QStringList headerLabels;
for(int i=1; i<=rowCount; i++){
    headerLabels << QString::number(i);
}
ui->tableWidget->setVerticalHeaderLabels(headerLabels);

2.自定义QTableWidget的QHeaderView，将其设置为显示行号。示例代码如下：

// 自定义QHeaderView
class LineNumberHeaderView : public QHeaderView
{
public:
    LineNumberHeaderView(Qt::Orientation orientation, QWidget *parent = nullptr)
        : QHeaderView(orientation, parent)
    {
        setDefaultAlignment(Qt::AlignRight | Qt::AlignVCenter);
    }

protected:
    void paintSection(QPainter *painter, const QRect &rect, int logicalIndex) const override
    {
        painter->save();

        QStyleOptionHeader opt;
        initStyleOption(&opt);
        opt.rect = rect;
        opt.section = logicalIndex;

        style()->drawControl(QStyle::CE_Header, &opt, painter, this);

        painter->setPen(QColor(0, 0, 0));
        painter->drawText(rect.adjusted(0, 0, -3, 0), Qt::AlignRight | Qt::AlignVCenter,
                          QString::number(logicalIndex + 1));

        painter->restore();
    }
};

// 设置行数和列数
int rowCount = 5;
int columnCount = 3;
ui->tableWidget->setRowCount(rowCount);
ui->tableWidget->setColumnCount(columnCount);

// 设置自定义QHeaderView
ui->tableWidget->setVerticalHeader(new LineNumberHeaderView(Qt::Vertical, ui->tableWidget));