(2013-08-03 10:53:53)
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。
XML文件：
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person
if(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());
}