设置文字和设置按钮或者其他控件都是可以的
QTableView设置表格左上的文字主要方法是继承后通过绘制在左上角

首先写一个类继承QTableView
class GCornerTableView : public QTableView
GCornerTableView.h

#ifndef GCORNERTABLEVIEW_H
#define GCORNERTABLEVIEW_H

#include <QPainter>
#include <QTableView>
#include <QAbstractButton>

class GCornerTableView : public QTableView
{
    Q_OBJECT

public:
    explicit GCornerTableView(QWidget *parent = 0);
    void setCornerButtonText(const QString &text);
    void setCornerTextAlignment(Qt::Alignment align);

private:
    QString m_cornerButtonText;

    Q_DECLARE_PRIVATE(QTableView)
};


class GTableCornerButton : public QAbstractButton
{
    Q_OBJECT

public:
    GTableCornerButton(QWidget *parent = 0)
        : QAbstractButton(parent)
    {

    }

    void paintEvent(QPaintEvent*)
    {
        QStyleOptionHeader opt;
        opt.initFrom(this);
        QStyle::State state = QStyle::State_None | QStyle::State_Raised;

        if (isEnabled())
        {
            state |= QStyle::State_Enabled;
        }

        if (isActiveWindow())
        {
            state |= QStyle::State_Active;
        }

        if (isDown())
        {
            state |= QStyle::State_Sunken;
        }

        opt.state = state;
        opt.text = m_text;
        opt.rect = rect();
        opt.position = QStyleOptionHeader::OnlyOneSection;
        opt.textAlignment = m_align;
        QPainter painter(this);
        style()->drawControl(QStyle::CE_Header, &opt, &painter, this);
    }

    void setText(const QString &text) {m_text = text;}
    void setAlignment(Qt::Alignment align) {m_align = align;}

private:
    QString m_text;
    Qt::Alignment m_align;
};

#endif // GCORNERTABLEVIEW_H

GCornerTableView.cpp

#include "gcornertableview.h"

#include <QHeaderView>
#include <QFontMetrics>
#include <private/qtableview_p.h>

GCornerTableView::GCornerTableView(QWidget *parent)
    : QTableView(parent)
{
    Q_D(QTableView);

    disconnect(d->cornerWidget, SIGNAL(clicked()), this, SLOT(selectAll()));
    delete d->cornerWidget;
    GTableCornerButton *btn = new GTableCornerButton(this);
    btn->setAlignment(Qt::AlignCenter);
    d->cornerWidget = btn;
    d->cornerWidget->setFocusPolicy(Qt::NoFocus);
    d->cornerWidget->setFont(d->verticalHeader->font());//cornerbutton used for verticalheader
//    QObject::connect(d->cornerWidget, SIGNAL(clicked()), this, SLOT(selectAll()));
}

void GCornerTableView::setCornerButtonText(const QString &text)
{
    Q_D(QTableView);

    m_cornerButtonText = text;
    GTableCornerButton *btn = static_cast<GTableCornerButton *>(d->cornerWidget);
    Q_ASSERT(btn);
    btn->setText(m_cornerButtonText);

    QFontMetrics metrics(btn->font());
    int width = metrics.width(m_cornerButtonText);
    int height = metrics.height();
    d->verticalHeader->setMinimumWidth(width + metrics.maxWidth());
    d->verticalHeader->setMinimumHeight(height + metrics.maxWidth());
    d->verticalHeader->setDefaultAlignment(Qt::AlignCenter);
}

void GCornerTableView::setCornerTextAlignment(Qt::Alignment align)
{
    Q_D(QTableView);

    GTableCornerButton *btn = static_cast<GTableCornerButton *>(d->cornerWidget);
    Q_ASSERT(btn);
    btn->setAlignment(align);
    btn->repaint();
}

然后是在mainwindow中使用测试

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "GCornerTableView.h"

#include <QVBoxLayout>
#include <QStandardItemModel>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    GCornerTableView *pCornerTableView = new GCornerTableView(this);

    QStandardItemModel *pModel = new QStandardItemModel(10, 10, pCornerTableView);
    pCornerTableView->setModel(pModel);

    pCornerTableView->setCornerButtonText(QStringLiteral("测试"));

    QVBoxLayout* pLayout = new QVBoxLayout();
    pLayout->addWidget(pCornerTableView);

    ui->centralWidget->setLayout(pLayout);
}

MainWindow::~MainWindow()
{
    delete ui;
}