用C++保存QTreeWidget三层六列数据到xml，再读取xml显示为QTreeWidget

以下是一个示例代码，展示如何使用Qt的QDomDocument类保存和读取一个QTreeWidget的数据到xml文件中：

#include <QtWidgets>

void saveTreeWidgetToXml(QTreeWidget* treeWidget, const QString& fileName) {
    QDomDocument doc;
    QDomElement root = doc.createElement("TreeWidget");
    doc.appendChild(root);

    for (int i = 0; i < treeWidget->topLevelItemCount(); ++i) {
        QTreeWidgetItem* topLevelItem = treeWidget->topLevelItem(i);

        QDomElement topLevelElement = doc.createElement("TopLevelItem");
        topLevelElement.setAttribute("text", topLevelItem->text(0));
        root.appendChild(topLevelElement);

        for (int j = 0; j < topLevelItem->childCount(); ++j) {
            QTreeWidgetItem* childItem = topLevelItem->child(j);

            QDomElement childElement = doc.createElement("ChildItem");
            childElement.setAttribute("text", childItem->text(0));
            topLevelElement.appendChild(childElement);

            for (int k = 1; k < treeWidget->columnCount(); ++k) {
                QDomElement columnElement = doc.createElement("Column");
                columnElement.setAttribute("index", k);
                columnElement.setAttribute("text", childItem->text(k));
                childElement.appendChild(columnElement);
            }
        }
    }

    QFile file(fileName);
    if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
        qDebug() << "Failed to open file for writing: " << fileName;
        return;
    }

    QTextStream stream(&file);
    stream << doc.toString();
    file.close();
}

void loadTreeWidgetFromXml(QTreeWidget* treeWidget, const QString& fileName) {
    QDomDocument doc;
    QFile file(fileName);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        qDebug() << "Failed to open file for reading: " << fileName;
        return;
    }

    if (!doc.setContent(&file)) {
        qDebug() << "Failed to parse XML document.";
        file.close();
        return;
    }
    file.close();

    QDomElement root = doc.documentElement();
    if (root.tagName() != "TreeWidget") {
        qDebug() << "Invalid root element: " << root.tagName();
        return;
    }

    treeWidget->clear();
    QDomNodeList topLevelNodes = root.elementsByTagName("TopLevelItem");
    for (int i = 0; i < topLevelNodes.count(); ++i) {
        QDomElement topLevelElement = topLevelNodes.at(i).toElement();
        QTreeWidgetItem* topLevelItem = new QTreeWidgetItem(treeWidget);
        topLevelItem->setText(0, topLevelElement.attribute("text"));

        QDomNodeList childNodes = topLevelElement.elementsByTagName("ChildItem");
        for (int j = 0; j < childNodes.count(); ++j) {
            QDomElement childElement = childNodes.at(j).toElement();
            QTreeWidgetItem* childItem = new QTreeWidgetItem(topLevelItem);
            childItem->setText(0, childElement.attribute("text"));

            QDomNodeList columnNodes = childElement.elementsByTagName("Column");
            for (int k = 0; k < columnNodes.count(); ++k) {
                QDomElement columnElement = columnNodes.at(k).toElement();
                int column = columnElement.attribute("index").toInt();
                QString text = columnElement.attribute("text");
                childItem->setText(column, text);
            }
        }
    }
}

int main(int argc, char* argv[]) {
    QApplication app(argc, argv);
    QTreeWidget* treeWidget = new QTreeWidget;
    treeWidget->setColumnCount(6);
    treeWidget->setHeaderLabels(QStringList() << "Column 1" << "Column 2" << "Column 3" << "Column 4" << "Column 5" << "Column 6");

    // Add some data to the tree widget
    QTreeWidgetItem* topLevelItem1 = new QTreeWidgetItem(treeWidget);
    topLevelItem1->setText(0, "Top Level Item 1");

    QTreeWidgetItem* childItem1 = new QTreeWidgetItem(topLevelItem1);
    childItem1->setText(0, "Child Item 1");
    childItem1->setText(1, "Data 1");
    childItem1->setText(2, "Data 2");
    childItem1->setText(3, "Data 3");
    childItem1->setText(4, "Data 4");
    childItem1->setText(5, "Data 5");

    QTreeWidgetItem* childItem2 = new QTreeWidgetItem(topLevelItem1);
    childItem2->setText(0, "Child Item 2");
    childItem2->setText(1, "Data 6");
    childItem2->setText(2, "Data 7");
    childItem2->setText(3, "Data 8");
    childItem2->setText(4, "Data 9");
    childItem2->setText(5, "Data 10");

    QTreeWidgetItem* topLevelItem2 = new QTreeWidgetItem(treeWidget);
    topLevelItem2->setText(0, "Top Level Item 2");

    QTreeWidgetItem* childItem3 = new QTreeWidgetItem(topLevelItem2);
    childItem3->setText(0, "Child Item 3");
    childItem3->setText(1, "Data 11");
    childItem3->setText(2, "Data 12");
    childItem3->setText(3, "Data 13");
    childItem3->setText(4, "Data 14");
    childItem3->setText(5, "Data 15");

    saveTreeWidgetToXml(treeWidget, "treeWidget.xml");
    loadTreeWidgetFromXml(treeWidget, "treeWidget.xml");

    treeWidget->show();
    return app.exec();
}