If you are using Qt 5, QHeaderView::setResizeMode()
is no longer available. Instead, you can use QHeaderView::setSectionResizeMode()
:
ui->tableView->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);
Or just call it for every column:
for (int c = 0; c < ui->tableView->horizontalHeader()->count(); ++c)
{
ui->tableView->horizontalHeader()->setSectionResizeMode(
c, QHeaderView::Stretch);
}