1 概述

    Qt中解析XML檔案有多種方法，參考資料[1]使用QXmlStreamReader類來讀取並解析xml檔案，而參考資料[2]則使用QDomDocument類來解析xml檔案。

2 QDomDocument

    參考資料[2][3][4]都給出了QDomDocument解析xml檔案的方法，下面是一個用於測試的xml檔案：

<?xml version="1.0" encoding="UTF-8"?>
<datainformations>
    <dataspacing>
        <X>0.31341081081</X>
        <Y>0.31341081081</Y>
        <Z>0.08581081081</Z>
    </dataspacing>
    <dataorigin>
        <X>0.00000000000</X>
        <Y>0.00000000000</Y>
        <Z>0.00000000000</Z>
    </dataorigin>
</datainformations>
 

void parseXML(const QString &fname)
{
    if(fname.isEmpty())
        return;

    QFile file(fname);
    if(!file.open(QFile::ReadOnly | QFile::Text)) {
        QMessageBox::information(nullptr, QString("title"),
                                 QString("open error!"));

        return;
    }

    QDomDocument domDocument;
    QString error;
    int row = 0, column = 0;
    if(!domDocument.setContent(&file, false, &error, &row, &column)) {
        QMessageBox::information(nullptr, QString("Error"),
                                 QString("parse file failed at line row and column") +
                                 QString::number(row, 10) + QString(",") +
                                 QString::number(column, 10));
        file.close();
        return;
    }

    if(domDocument.isNull()) {
        QMessageBox::information(nullptr, QString("title"),
                                 QString("document is null!"));

        file.close();
        return;
    }

    const QDomElement domElement = domDocument.documentElement();

    const QString domElementTagName = domElement.tagName();

    if (domElementTagName != DOMELEMENT_TAGNAME) {
        QMessageBox::information(nullptr, QString("title"),
                                 QString("Root Name is wrong!"));

        file.close();
        return;
    }

    QVector3D dataspacing;
    QVector3D dataorigin;
    const QDomNodeList spacingOriginList = domElement.childNodes();
    for(int i = 0; i < spacingOriginList.count(); ++i) {
        const QDomNode spacingNode = spacingOriginList.item(i);
        const QDomElement spacingElement = spacingNode.toElement();
        const QString spacingTagName = spacingElement.tagName();

        QVector3D *data = nullptr;
        if (spacingTagName == "dataspacing") {
            data = &dataspacing;
        } else if (spacingTagName == "dataorigin"){
            data = &dataorigin;
        }
        if (!data)
            continue;

        const QDomNodeList xyzList = spacingElement.childNodes();
        for(int j = 0; j < xyzList.count(); ++j) {
            const QDomNode xNode = xyzList.item(j);
            const QDomElement xElement = xNode.toElement();

            const QString xTagName = xElement.tagName();
            const QString xTagValue = xElement.text();
            if (xTagName == "X") {
                data->setX(xTagValue.toDouble());
            } else if (xTagName == "Y") {
                data->setY(xTagValue.toDouble());
            } else if (xTagName == "Z") {
                data->setZ(xTagValue.toDouble());
            }
        }
    }

    file.close();

    qDebug() << "spacing:" << dataspacing;
    qDebug() << "origin:" << dataorigin;
}
 

參考資料