Qt解析多级xml文件

class ParamSettingDlg : public QDialog
{
    Q_OBJECT

public:
    explicit ParamSettingDlg(QWidget *parent = nullptr);
    ~ParamSettingDlg();

private:
    Ui::ParamSettingDlg *ui;

    QStandardItemModel *model;
};

void ParamSettingDlg::LoadClassifyFile()
{
    QDomDocument doc;
    QString strXMLPath = QApplication::applicationDirPath() + + "/config/classify.xml";

    model = new QStandardItemModel(ui->treeView);
    model->setHorizontalHeaderLabels(QStringList()<<QStringLiteral("Classify"));

    QFile file(strXMLPath);
    if (!file.open(QIODevice::ReadOnly))
        return;

    QString strError;
    int iErrCount;
    int iErrLine;
    if ( !doc.setContent(&file, false, &strError, &iErrLine, &iErrCount) )
    {
        LoggerInfo::GetInstance()->WriteLog(LOG_LEVEL_ERROR,"Open XML Failed : " + strError ,__FUNCTION__,__LINE__);
        file.close();
        return ;
    }

    //! 根节点
    QDomElement root = doc.documentElement();

    //一级节点
    QDomElement firstNode = root.firstChildElement("first");
    for (; !firstNode.isNull(); firstNode = firstNode.nextSiblingElement("first"))
    {
        QList<QStandardItem*> firstItems;
        QStandardItem* item1 = new QStandardItem(firstNode.attribute("name"));
        firstItems.append(item1);
        model->appendRow(firstItems);

        ui->comboBox->addItem(item1->text());

        //二级节点
        QDomElement secondNode = firstNode.firstChildElement("second");
        for (; !secondNode.isNull(); secondNode = secondNode.nextSiblingElement("second"))
        {
            QList<QStandardItem*> secondItems;
            QStandardItem* item2 = new QStandardItem(secondNode.attribute("name"));
            secondItems.append(item2);
            item1->appendRow(secondItems);

            ui->comboBox->addItem(item2->text());

            //三级节点
            QDomElement thirdNode = secondNode.firstChildElement("third");
            for (; !thirdNode.isNull(); thirdNode = thirdNode.nextSiblingElement("third"))
            {
                QList<QStandardItem*> thirdItems;
                QStandardItem* item3 = new QStandardItem(thirdNode.attribute("name"));
                thirdItems.append(item3);
                item2->appendRow(thirdItems);

                ui->comboBox->addItem(item3->text());
            }
        }

    }

    ui->treeView->setModel(model);
}