Checkbox Setfocus

I need an example, as moves to a qlineedit after i presses a checkbox:
something like that

Code:

---

ui->txtGarg - QLineEdit
 
void protocolonutri::on_cboOthersGarg_toggled(bool checked)
{
    ui->txtGarg->setEnabled(checked);
    if (!checked)
         ui->txtGarg->setText("");
 
else
      ui->txtGarg->setFocus();
}

---

SetFocus Doesnt Work Well, how i can do?
Sorry for my english

Try setFocus(Qt::OtherFocusReason)

i try but dont work