下面是一个读写xml文件的示例代码：
#include <QCoreApplication>
#include <QXmlStreamReader>
#include <QXmlStreamWriter>
#include <QDebug>
#include <QFile>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
// 创建一个XML文档，写入一些数据
QFile file("data.xml");
if (file.open(QIODevice::WriteOnly)) {
QXmlStreamWriter writer(&file);
writer.setAutoFormatting(true);
writer.writeStartDocument();
writer.writeStartElement("people");
writer.writeStartElement("person");
writer.writeAttribute("name", "John");
writer.writeTextElement("age", "35");
writer.writeTextElement("gender", "male");
writer.writeEndElement(); // person
writer.writeStartElement("person");
writer.writeAttribute("name", "Mary");
writer.writeTextElement("age", "28");
writer.writeTextElement("gender", "female");
writer.writeEndElement(); // person
writer.writeEndElement(); // people
writer.writeEndDocument();
file.close();
}
// 读取XML文件中的数据
if (file.open(QIODevice::ReadOnly)) {
QXmlStreamReader reader(&file);
while (!reader.atEnd()) {
reader.readNext();
if (reader.isStartElement() && reader.name() == "person") {
QString name = reader.attributes().value("name").toString();
QString age;
QString gender;
while (reader.readNextStartElement()) {
if (reader.name() == "age")
age = reader.readElementText();
else if (reader.name() == "gender")
gender = reader.readElementText();
else
reader.skipCurrentElement();
}
qDebug() << "Name:" << name << "Age:" << age << "Gender:" << gender;
}
}
if (reader.hasError())
qDebug() << "XML error:" << reader.errorString();
file.close();
}
return a.exec();
}
这个示例程序创建了一个XML文件，并在其中写入了两个人的信息。然后它再次打开该文件，读取其中的数据，并将其输出到控制台。
输出结果如下：
Name: "John" Age: "35" Gender: "male"
Name: "Mary" Age: "28" Gender: "female"
