代码出自Qt Creator 快速入门，这里只是做个记载

xml

<?xml version="1.0" encoding="UTF-8"?>
<library>
	<book id="01">
		<title>Qt</title>
		<author>shiming</author>
	</book>
	<book id="02">
		<title>linux</title>
		<author>shiming</author>
	</book>
</library>

mysax.h

#ifndef MYSAX_H
#define MYSAX_H

#include <QXmlDefaultHandler>
class QListWidget;

class MySAX : public QXmlDefaultHandler
{
public:
    MySAX();
    ~MySAX();
    bool readFile(const QString &fileName);
protected:
    bool startElement(const QString &namespaceURI,const QString &localName,const QString &qName,const QXmlAttributes &atts);
    bool endElement(const QString &namespaceURI,const QString &qName);
    bool characters(const QString &ch);
    bool fatalError(const QXmlParseException &exception);

private:
    QListWidget *list;
    QString currentText;
};

#endif // MYSAX_H

mysax.cpp

#include "mysax.h"
#include <QtXml>
#include <QListWidget>

MySAX::MySAX()
{
    list = new QListWidget;
    list->show();
}

MySAX::~MySAX()
{
    delete list;
}

bool MySAX::readFile(const QString &fileName)
{
    QFile file(fileName);
    // 读取文件内容
    QXmlInputSource inputSource(&file);
    // 建立QXmlSimpleReader对象
    QXmlSimpleReader reader;
    // 设置内容处理器
    reader.setContentHandler(this);
    // 设置错误处理器
    reader.setErrorHandler(this);
    // 解析文件
    return reader.parse(inputSource);
}

// 已经解析完一个元素的起始标签
bool MySAX::startElement(const QString &namespaceURI,const QXmlAttributes &atts)
{
    if (qName == "library")
        list->addItem(qName);
    else if (qName == "book")
        list->addItem("    " + qName + atts.value("id"));
    return true;
}

// 已经解析完一块字符数据
bool MySAX::characters(const QString &ch)
{
    currentText = ch;
    return true;
}

// 已经解析完一个元素的结束标签
bool MySAX::endElement(const QString &namespaceURI,const QString &qName)
{
    if (qName == "title" || qName == "author")
        list->addItem("        " + qName + " : " + currentText);
    return true;
}

// 错误处理
bool MySAX::fatalError(const QXmlParseException &exception)
{
    qDebug() << exception.message();
    return false;
}

main.cpp

#include "mysax.h"
#include <QApplication>

int main(int argc,char* argv[])
{
    QApplication app(argc,argv);
    MySAX sax;
    sax.readFile("../mySAX/my.xml");
    return app.exec();
}