Qt 解析XML文件 QXmlStreamReader

如何使用QXmlStreamReader来解析格式良好的XML，Qt的文档中指出，它是一种更快、更方便的Qt自己的SAX解析器（QXmlSimpleReader）的替代，它也较快，在某种情况下，比DOM（QDomDocument）更方便。

 

   解析方法：
void ParseXML::parseXML(QString file_name)
{if(file_name.isEmpty())  return;  QFile *file = new QFile(file_name);  if(!file->open(QFile::ReadOnly | QFile::Text)) {  QMessageBox::information(NULL, QString("title"), QString("open error!"));return;  }  //QXmlStreamReader操作任何QIODevice.QXmlStreamReader xml(file);QList> persons;//解析XML，直到结束while(!xml.atEnd() && !xml.hasError()){//读取下一个element.QXmlStreamReader::TokenType token = xml.readNext();//如果获取的仅为StartDocument,则进行下一个if(token == QXmlStreamReader::StartDocument) {continue;}//如果获取了StartElement,则尝试读取if(token == QXmlStreamReader::StartElement){//如果为persons，直接进入下一个if(xml.name() == "persons"){continue;}//如果为person，则对其进行解析if(xml.name() == "person"){persons.append(this->parsePerson(xml));}}}if(xml.hasError()){QMessageBox::information(NULL, QString("parseXML"), xml.errorString());}//从reader中删除所有设备、数据，并将其重置为初始状态xml.clear();
}QMap ParseXML::parsePerson(QXmlStreamReader& xml)
{QMap person;//检查是否获取personif(xml.tokenType() != QXmlStreamReader::StartElement && xml.name() == "person"){return person;}//获取person属性QXmlStreamAttributes attributes = xml.attributes();if(attributes.hasAttribute("id")) {person["id"] = attributes.value("id").toString();}//操作下一个xml.readNext();while(!(xml.tokenType() == QXmlStreamReader::EndElement && xml.name() == "person")) {if(xml.tokenType() == QXmlStreamReader::StartElement){if(xml.name() == "name"){this->addElementDataToMap(xml, person);}if(xml.name() == "age") {this->addElementDataToMap(xml, person);}if(xml.name() == "email") {this->addElementDataToMap(xml, person);}if(xml.name() == "website") {this->addElementDataToMap(xml, person);}}xml.readNext();}QString id = person["id"];QString name = person["name"];QString age =  person["age"];QString email = person["email"];QString website = person["website"];return person;
}void ParseXML::addElementDataToMap(QXmlStreamReader& xml, QMap& map) const
{if(xml.tokenType() != QXmlStreamReader::StartElement) {return;}QString elementName = xml.name().toString();xml.readNext();if(xml.tokenType() != QXmlStreamReader::Characters) {return;}map.insert(elementName, xml.text().toString());
}