使用 Qt C++ 解析和处理 XML 文件
以下是使用 Qt C++ 实现 XML 文件处理的几种方法，包括解析、创建和修改 XML 文件。
1. 使用 QXmlStreamReader (推荐方式)
#include <QFile>
#include <QXmlStreamReader>
#include <QDebug>void parseXmlWithStream(const QString &filePath) {QFile file(filePath);if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {qDebug() << "无法打开文件:" << filePath;return;}QXmlStreamReader xml(&file);while (!xml.atEnd()) {xml.readNext();if (xml.isStartElement()) {qDebug() << "开始元素:" << xml.name();// 打印所有属性for (const auto &attr : xml.attributes()) {qDebug() << " 属性:" << attr.name() << "=" << attr.value();}} else if (xml.isEndElement()) {qDebug() << "结束元素:" << xml.name();} else if (xml.isCharacters() && !xml.isWhitespace()) {qDebug() << "文本内容:" << xml.text().trimmed();}}if (xml.hasError()) {qDebug() << "XML 解析错误:" << xml.errorString();}file.close();
}// 使用示例
int main() {parseXmlWithStream("example.xml");return 0;
}
2. 使用 QDomDocument (DOM 方式)
#include <QDomDocument>
#include <QFile>
#include <QDebug>void parseXmlWithDom(const QString &filePath) {QFile file(filePath);if (!file.open(QIODevice::ReadOnly)) {qDebug() << "无法打开文件:" << filePath;return;}QDomDocument doc;if (!doc.setContent(&file)) {qDebug() << "无法解析 XML 文件";file.close();return;}file.close();QDomElement root = doc.documentElement();qDebug() << "根元素:" << root.tagName();// 递归遍历所有节点std::function<void(const QDomNode &, int)> traverseNode = [&traverseNode](const QDomNode &node, int indent) {QDomNode n = node;while (!n.isNull()) {qDebug().noquote() << QString(indent, ' ') << "节点:" << n.nodeName();if (n.isElement()) {QDomElement e = n.toElement();if (e.hasAttributes()) {QDomNamedNodeMap attrs = e.attributes();for (int i = 0; i < attrs.length(); ++i) {QDomNode attr = attrs.item(i);qDebug().noquote() << QString(indent+2, ' ') << "属性:" << attr.nodeName() << "=" << attr.nodeValue();}}}if (n.hasChildNodes()) {QDomNode child = n.firstChild();while (!child.isNull()) {if (child.isText()) {QString text = child.nodeValue().trimmed();if (!text.isEmpty()) {qDebug().noquote() << QString(indent+2, ' ') << "文本:" << text;}} else {traverseNode(child, indent+2);}child = child.nextSibling();}}n = n.nextSibling();}};traverseNode(root.firstChild(), 0);
}// 使用示例
int main() {parseXmlWithDom("example.xml");return 0;
}
3. 解析 Qt UI 文件示例
#include <QDomDocument>
#include <QFile>
#include <QDebug>void parseUiFile(const QString &uiFile) {QFile file(uiFile);if (!file.open(QIODevice::ReadOnly)) {qDebug() << "无法打开 UI 文件:" << uiFile;return;}QDomDocument doc;if (!doc.setContent(&file)) {qDebug() << "无法解析 UI 文件";file.close();return;}file.close();QDomElement root = doc.documentElement();// 查找所有 widget 元素QDomNodeList widgets = root.elementsByTagName("widget");qDebug() << "找到" << widgets.count() << "个 widget";for (int i = 0; i < widgets.count(); ++i) {QDomElement widget = widgets.at(i).toElement();QString name = widget.attribute("name");QString className = widget.attribute("class");qDebug() << "Widget" << i+1 << ":" << name << "(" << className << ")";}// 查找所有连接QDomNodeList connections = root.elementsByTagName("connection");qDebug() << "\n找到" << connections.count() << "个连接";for (int i = 0; i < connections.count(); ++i) {QDomElement connection = connections.at(i).toElement();QString sender = connection.firstChildElement("sender").text();QString signal = connection.firstChildElement("signal").text();QString receiver = connection.firstChildElement("receiver").text();QString slot = connection.firstChildElement("slot").text();qDebug() << "连接" << i+1 << ":" << sender << "." << signal << "->" << receiver << "." << slot;}
}// 使用示例
int main() {parseUiFile("mainwindow.ui");return 0;
}
4. 创建 Qt XML 文件
#include <QDomDocument>
#include <QFile>
#include <QTextStream>
#include <QDebug>void createQtXml(const QString &outputFile) {QDomDocument doc("QtConfig");// 创建处理指令QDomProcessingInstruction instr = doc.createProcessingInstruction("xml", "version=\"1.0\" encoding=\"UTF-8\"");doc.appendChild(instr);// 创建根元素QDomElement root = doc.createElement("QtSettings");root.setAttribute("version", "1.0");doc.appendChild(root);// 添加窗口设置QDomElement window = doc.createElement("Window");window.setAttribute("name", "MainWindow");root.appendChild(window);QDomElement width = doc.createElement("Width");width.appendChild(doc.createTextNode("800"));window.appendChild(width);QDomElement height = doc.createElement("Height");height.appendChild(doc.createTextNode("600"));window.appendChild(height);// 添加按钮设置QDomElement button = doc.createElement("Button");button.setAttribute("name", "btnOK");root.appendChild(button);QDomElement text = doc.createElement("Text");text.appendChild(doc.createTextNode("OK"));button.appendChild(text);// 保存到文件QFile file(outputFile);if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {qDebug() << "无法写入文件:" << outputFile;return;}QTextStream stream(&file);doc.save(stream, 2); // 2 表示缩进空格数file.close();qDebug() << "已创建 Qt XML 文件:" << outputFile;
}// 使用示例
int main() {createQtXml("qt_config.xml");return 0;
}
5. 修改 Qt XML 文件
#include <QDomDocument>
#include <QFile>
#include <QTextStream>
#include <QDebug>void modifyQtXml(const QString &inputFile, const QString &outputFile) {QFile file(inputFile);if (!file.open(QIODevice::ReadOnly)) {qDebug() << "无法打开文件:" << inputFile;return;}QDomDocument doc;if (!doc.setContent(&file)) {qDebug() << "无法解析 XML 文件";file.close();return;}file.close();QDomElement root = doc.documentElement();// 修改所有 Button 元素的文本QDomNodeList buttons = root.elementsByTagName("Button");for (int i = 0; i < buttons.count(); ++i) {QDomElement button = buttons.at(i).toElement();QDomElement textElem = button.firstChildElement("Text");if (!textElem.isNull()) {QDomNode textNode = textElem.firstChild();textNode.setNodeValue("New Text");}}// 添加新元素QDomElement newButton = doc.createElement("Button");newButton.setAttribute("name", "btnCancel");QDomElement newText = doc.createElement("Text");newText.appendChild(doc.createTextNode("Cancel"));newButton.appendChild(newText);root.appendChild(newButton);// 保存修改QFile outFile(outputFile);if (!outFile.open(QIODevice::WriteOnly | QIODevice::Text)) {qDebug() << "无法写入文件:" << outputFile;return;}QTextStream stream(&outFile);doc.save(stream, 2);outFile.close();qDebug() << "已修改并保存到:" << outputFile;
}// 使用示例
int main() {modifyQtXml("qt_config.xml", "qt_config_modified.xml");return 0;
}
6. 使用 SAX 解析器 (QXmlSimpleReader)
#include <QXmlSimpleReader>
#include <QXmlInputSource>
#include <QFile>
#include <QDebug>class MyXmlHandler : public QXmlDefaultHandler {
public:bool startElement(const QString &namespaceURI, const QString &localName,const QString &qName, const QXmlAttributes &attributes) override {qDebug() << "开始元素:" << qName;for (int i = 0; i < attributes.count(); ++i) {qDebug() << " 属性:" << attributes.qName(i) << "=" << attributes.value(i);}return true;}bool endElement(const QString &namespaceURI,const QString &localName,const QString &qName) override {qDebug() << "结束元素:" << qName;return true;}bool characters(const QString &ch) override {QString text = ch.trimmed();if (!text.isEmpty()) {qDebug() << "文本内容:" << text;}return true;}bool fatalError(const QXmlParseException &exception) override {qDebug() << "XML 解析错误:" << exception.message();return false;}
};void parseXmlWithSax(const QString &filePath) {QFile file(filePath);if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {qDebug() << "无法打开文件:" << filePath;return;}QXmlSimpleReader reader;MyXmlHandler handler;reader.setContentHandler(&handler);reader.setErrorHandler(&handler);QXmlInputSource source(&file);if (!reader.parse(&source)) {qDebug() << "解析失败";}file.close();
}// 使用示例
int main() {parseXmlWithSax("example.xml");return 0;
}
总结
- QXmlStreamReader - 流式解析器，内存效率高，适合大文件
- QDomDocument - DOM 解析器，适合小文件，便于随机访问和修改
- SAX 解析器 - 事件驱动模型，适合只需读取不需要修改的情况
- 对于 Qt UI 文件，可以使用上述任意方法解析
选择建议：
- 大文件或只需顺序读取 → QXmlStreamReader
- 需要频繁修改或随机访问 → QDomDocument
- 特殊需求或性能关键 → SAX 解析器
from PyQt5.QtCore import QFile, QIODevice, QXmlStreamReaderdef parse_xml_with_stream(file_path):file = QFile(file_path)if not file.open(QIODevice.ReadOnly | QIODevice.Text):print(f"无法打开文件: {file_path}")returnxml = QXmlStreamReader(file)while not xml.atEnd():xml.readNext()if xml.isStartElement():print(f"开始元素: {xml.name()}")# 打印所有属性for attr in xml.attributes():print(f" 属性: {attr.name()} = {attr.value()}")elif xml.isEndElement():print(f"结束元素: {xml.name()}")elif xml.isCharacters() and not xml.isWhitespace():print(f"文本内容: {xml.text().strip()}")if xml.hasError():print(f"XML 解析错误: {xml.errorString()}")file.close()if __name__ == "__main__":# 替换为你的 XML 文件路径xml_file_path = r"D:\shawei\temp\jpbalance\temp\TaskTemplates\Shock Pulse.xml"parse_xml_with_stream(xml_file_path)import xml.etree.ElementTree as ETdef parse_xml_with_et(file_path):try:tree = ET.parse(file_path)root = tree.getroot()# 命名空间处理ns = {'cm': 'http://www.pruftechnik.com/cm'}print("=== 任务模板 ===")print(f"版本: {root.get('version')}")print(f"任务ID: {root.get('task_id')}")print(f"名称: {root.get('name')}")print(f"来源: {root.get('source')}")meas_setup = root.find('cm:meas_setup', ns)print("\n=== 测量设置 ===")print(f"类型: {meas_setup.get('kind')}")spectrum = meas_setup.find('cm:spectrum', ns)print("\n=== 频谱配置 ===")print(f"名称: {spectrum.get('name')}")print(f"资源ID: {spectrum.get('res_id')}")print(f"量值: {spectrum.get('quant')}")print(f"线数: {spectrum.get('lines')}")print(f"窗函数: {spectrum.get('window')}")time_waveform = spectrum.find('cm:time_waveform_config', ns)print("\n=== 时域波形配置 ===")print(f"名称: {time_waveform.get('name')}")print(f"资源ID: {time_waveform.get('res_id')}")print(f"量值: {time_waveform.get('quant')}")average = spectrum.find('cm:average', ns)print("\n=== 平均设置 ===")print(f"平均次数: {average.get('num')}")print(f"重叠率: {average.get('overlap')}%")print(f"因子: {average.get('factor')}")print(f"类型: {average.get('type')}")freq_spectrum = spectrum.find('cm:freq_spectrum', ns)print("\n=== 频谱范围 ===")print(f"最大频率: {freq_spectrum.get('max')}Hz")print(f"最大类型: {freq_spectrum.get('max_type')}")print(f"最小频率: {freq_spectrum.get('min')}Hz")except ET.ParseError as e:print(f"XML 解析错误: {e}")except Exception as e:print(f"发生错误: {e}")if __name__ == "__main__":xml_file_path = r"D:\shawei\temp\jpbalance\temp\TaskTemplates\Shock Pulse.xml"parse_xml_with_et(xml_file_path)
<?xml version="1.0" encoding="UTF-8"?>
<task_template xmlns="http://www.xxxx.com/cm" version="4.0.0" task_id="00000000-0000-0000-0000-000000000003" name="Spec (a) 10Hz - 12800Hz" source="factory"><meas_setup kind="trending_spectrum_amplitude"><spectrum name="Spectrum Velocity" res_id="00000000-0000-0000-0000-000000000002" quant="acc" lines="51200" window="hanning"><time_waveform_config name="Time Waveform Velocity" res_id="00000000-0000-0000-0000-000000000001" quant="acc"/><average num="3" overlap="60" factor="0.5" type="lin"/><freq_spectrum max="12800" max_type="time_based" min="10"/></spectrum></meas_setup>
</task_template>
#include <QCoreApplication>
#include <QFile>
#include <QXmlStreamReader>
#include <QDebug>void parseTaskTemplateXml(const QString &filePath) {QFile file(filePath);if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {qDebug() << "无法打开文件:" << filePath;return;}QXmlStreamReader xml(&file);while (!xml.atEnd() && !xml.hasError()) {xml.readNext();if (xml.isStartElement()) {QString elementName = xml.name().toString();if (elementName == "task_template") {qDebug() << "=== 任务模板 ===";qDebug() << "命名空间:" << xml.namespaceUri();qDebug() << "版本:" << xml.attributes().value("version").toString();qDebug() << "任务ID:" << xml.attributes().value("task_id").toString();qDebug() << "名称:" << xml.attributes().value("name").toString();qDebug() << "来源:" << xml.attributes().value("source").toString();}else if (elementName == "meas_setup") {qDebug() << "\n=== 测量设置 ===";qDebug() << "类型:" << xml.attributes().value("kind").toString();}else if (elementName == "spectrum") {qDebug() << "\n=== 频谱配置 ===";qDebug() << "名称:" << xml.attributes().value("name").toString();qDebug() << "资源ID:" << xml.attributes().value("res_id").toString();qDebug() << "量值:" << xml.attributes().value("quant").toString();qDebug() << "线数:" << xml.attributes().value("lines").toString();qDebug() << "窗函数:" << xml.attributes().value("window").toString();}else if (elementName == "time_waveform_config") {qDebug() << "\n=== 时域波形配置 ===";qDebug() << "名称:" << xml.attributes().value("name").toString();qDebug() << "资源ID:" << xml.attributes().value("res_id").toString();qDebug() << "量值:" << xml.attributes().value("quant").toString();}else if (elementName == "average") {qDebug() << "\n=== 平均设置 ===";qDebug() << "平均次数:" << xml.attributes().value("num").toString();qDebug() << "重叠率:" << xml.attributes().value("overlap").toString() << "%";qDebug() << "因子:" << xml.attributes().value("factor").toString();qDebug() << "类型:" << xml.attributes().value("type").toString();}else if (elementName == "freq_spectrum") {qDebug() << "\n=== 频谱范围 ===";qDebug() << "最大频率:" << xml.attributes().value("max").toString() << "Hz";qDebug() << "最大类型:" << xml.attributes().value("max_type").toString();qDebug() << "最小频率:" << xml.attributes().value("min").toString() << "Hz";}}}if (xml.hasError()) {qDebug() << "XML 解析错误:" << xml.errorString();}file.close();
}int main(int argc, char *argv[]) {QCoreApplication a(argc, argv);parseTaskTemplateXml("task_template.xml");return a.exec();
}
