以下方法似乎有效...

std::map<int/* row */, std::map<int/* col */, QString> > stuff;
int minCol = std::numeric_limits<int>::max();
int maxCol = std::numeric_limits<int>::min();
for (int i = 0; i < selectedIndexes.count(); ++i) {
  QModelIndex current = selectedIndexes[i];
  int col = horizontalHeader()->visualIndex(current.column());
  stuff[current.row()][col] = current.data(Qt::DisplayRole).toString();
  minCol = std::min(minCol, current.column());
  maxCol = std::max(maxCol, current.column());
}

QString displayText;
for (const auto &byRow: stuff) {
  for (int col = minCol; col <= maxCol; ++col) {
    auto i = byRow.second.find(col);
    if (i != byRow.second.end())
      displayText += i->second;
    displayText += col == maxCol ? "\n" : "\t";
  }
}

注意索引列是如何使用...

int col = horizontalHeader()->visualIndex(current.column());

不管怎样，看看这是否更接近你的需要。

出于您的目的，最好使用 * 选择范围 *。

// If your selection is continuous, there should be just one range.
QItemSelectionRange range = selection->selection().front();

int row, col;
for (int i = 0; i < range.height(); i++)
{
    QStringList rowStrList;
    for (int j = 0; j < range.width(); j++)
    {
        row = range.top() + i;
        col = range.left() + j;
        rowStrList << model->index(row, col).data(Qt::DisplayRole).toString();
    }

    clipboardString += rowStrList.join("\t");
    clipboardString += "\n";
}

基本思想是逐行处理选择。
QItemSelectionModel::selection()返回QItemSelection，QItemSelection是 * 选择范围 * 的列表。* 选择范围 * 是所选索引的连续矩形集合。

要复制带有标题的QTable视图中的选择，可覆盖按键事件并按如下方式使用。
无效按键事件（QKeyEvent * 事件）{

this->setSelectionBehavior(QAbstractItemView::SelectRows);
    this->setSelectionMode(QAbstractItemView::MultiSelection);
    QModelIndexList selectedRows = selectionModel()->selectedRows();
    QModelIndexList selectedColumns = selectionModel()->selectedColumns();
if(event->key() == Qt::Key_Insert)
{
    tblview_model->customInsertRows();
}
else if(event->key() == Qt::Key_Delete)
{  if(!selectedRows.isEmpty())
        model()->removeRows(selectedRows.at(0).row(),
                            selectedRows.size());
}
else if(event->matches(QKeySequence::Paste)) {
    if(copyPasteEnabled == true){
        text = QApplication::clipboard()->text();
        if(!text.isEmpty()){
            tblview_model->pasteData(text);
        }
    }
}

if(!selectedIndexes().isEmpty()){
    if(event->matches(QKeySequence::Copy)){
        QString text;
        QStringList hdr_lst;
        const std::vector<std::string>& hdrs = tblview_model->getHeader();

        QItemSelectionRange range = selectionModel()->selection().first();
        if (!selectedColumns.isEmpty())
        {
            for (auto j = 0; j < selectedColumns.size(); ++j)
            {
                std::string hd = hdrs[selectedColumns.at(j).column()];
                if (std::find(hdrs.begin(), hdrs.end(), hd) != hdrs.end())
                    hdr_lst << QString::fromStdString(hd);
            }
            text += hdr_lst.join("\t");
            text += "\n";

            for (auto i = 0; i < tblview_model->rowCount(); ++i)
            {
                QStringList rowContents;
                for (auto j = 0; j < selectedColumns.size(); ++j)
                {
                    if (!isColumnHidden(j)) {
                        
                            rowContents << model()->index(i, selectedColumns.at(j).column()).data().toString();

                    
                }
                text += rowContents.join("\t");
                text += "\n";
            }
        }
        else if (!selectedRows.isEmpty())
        {
            for (auto h : hdrs)
            {
                hdr_lst << QString::fromStdString(h);
            }

            text += hdr_lst.join("\t");
            text += "\n";
            //for (auto i = range.top(); i <= range.bottom(); ++i)
            for (auto i = 0; i < selectedRows.size(); ++i)
            {
                QStringList rowContents;
                for (auto j = 0; j <= tblview_model->columnCount(); ++j)
                {
                    if (!isColumnHidden(j)) {
                        
                            rowContents << model()->index(selectedRows.at(i).row(), j).data().toString();}
                    
                }
                text += rowContents.join("\t");
                text += "\n";
            }
        }
        QApplication::clipboard()->setText(text);