用Qt中的QDomDocument类处理XML文件

参考：http://www.w3school.com.cn/xmldom/dom_document.asp 

 

虽然看过也用过XML方面的，但对QT如何处理XML还比较陌生，工作中也用，但主要是调用同事写好的接口
转载的目标，是消除QT如何处理xml(或应用)神秘感

下面命例子是如何写XML的(来自：http://www.qtcentre.org/forum/f-newbie-4/t-need-qdomdocument-example-20413.html)

.
.





#include

int main(int argc, char **argv)
{
 Q_UNUSED(argc);
 Q_UNUSED(argv);

 QFile file("text.xml");
 if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
  return 0;

 QDomDocument doc;
 QDomElement ui = doc.createElement("ui");
 ui.setAttribute("name", "UI EDITOR");

 QDomElement ribbon = doc.createElement("ribbon");
 ribbon.setAttribute("name", "ribbon");
 ui.appendChild(ribbon);

 QDomElement tab = doc.createElement("tab");
 tab.setAttribute("title", "simulation");
 ribbon.appendChild(tab);

 QDomElement panel = doc.createElement("panel");
 tab.appendChild(panel);

 for (int i = 0; i < 10; ++i) {
  QDomElement button = doc.createElement("button");
  button.setAttribute("tooltip", QString("scFileOpen('/home/vajindar/Project/auto%1.tin')").arg(i + 1));
  button.setAttribute("id", i + 1);
  panel.appendChild(button);
 }

 doc.appendChild(ui);
 QTextStream out(&file);
 out << doc.toString();

 return 0;
}

/**********************write xml******************/

#include
#include
#include
#include
#include
#include

struct Contact
{
 QString name;
 QString phone;
 QString eMail;
};

QDomElement ContactToNode( QDomDocument &d, const Contact &c )
{
 QDomElement cn = d.createElement( "contact" );

 cn.setAttribute( "name", c.name );
 cn.setAttribute( "phone", c.phone );
 cn.setAttribute( "email", c.eMail );

 return cn;
}

int main( int argc, char **argv )
{
 QApplication a( argc, argv );

 QDomDocument doc( "AdBookML" );
 QDomElement root = doc.createElement( "adbook" );
 doc.appendChild( root );

 Contact c;

 c.name = "Kal";
 c.eMail = "";
 c.phone = "[phone]";

 root.appendChild( ContactToNode( doc, c ) );

 c.name = "Ada";
 c.eMail = "";
 c.phone = "[phone]";

 root.appendChild( ContactToNode( doc, c ) );

 QFile file( "test01.xml" );
 if( !file.open( QFile::WriteOnly | QFile::Text ) )
  return -1;

 QTextStream ts( &file );
 ts << doc.toString();

 file.close();

 return 0;
}

/********************** read xml ***************/
struct Contact
{
 QString name;
 QString phone;
 QString eMail;
};
int main4()
{

 QDomDocument doc( "AdBookML" );
 QFile file( "test01.xml" );
 if( !file.open( QFile::ReadOnly | QFile::Text  ) )
  return -1;
 if( !doc.setContent( &file ) )
 {
  file.close();
  return -2;
 }
 file.close();

 QDomElement root = doc.documentElement();
 if( root.tagName() != "adbook" )
  return -3;

 QDomNode n = root.firstChild();
 while( !n.isNull() )
 {
  QDomElement e = n.toElement();
  if( !e.isNull() )
  {
   if( e.tagName() == "contact" )
   {
    Contact c;

    c.name = e.attribute( "name", "" );
    c.phone = e.attribute( "phone", "" );
    c.eMail = e.attribute( "email", "" );
    qDebug() << "Contact = " << c.name << "\n" << c.phone << "\n" << c.eMail;
    //QMessageBox::information( 0, "Contact", c.name + "\n" + c.phone + "\n" + c.eMail );
   }
  }

  n = n.nextSibling();
 }

 return 0;
}

 

/********************** sax xml ***************/

class AdBookParser : public QXmlDefaultHandler
{
public:
 bool startDocument()
 {
  inAdBook = false;
  return true;
 }
 bool endElement( const QString&, const QString&, const QString &name )
 {
  if( name == "adbook" )
   inAdBook = false;

  return true;
 }

 bool startElement( const QString&, const QString&, const QString &name, const QXmlAttributes &attrs )
 {
  if( inAdBook && name == "contact" )
  {
   QString name, phone, email;

   for( int i=0; i   {
    if( attrs.localName( i ) == "name" )
     name = attrs.value( i );
    else if( attrs.localName( i ) == "phone" )
     phone = attrs.value( i );
    else if( attrs.localName( i ) == "email" )
     email = attrs.value( i );
   }
   qDebug() << "Contact = " << name << "\n" << phone << "\n" << email;
   //QMessageBox::information( 0, "Contact", name + "\n" + phone + "\n" + email );
  }
  else if( name == "adbook" )
   inAdBook = true;

  return true;
 }

private:
 bool inAdBook;
};

int main_sax( int argc, char **argv )
{
 QApplication a( argc, argv );

 AdBookParser handler;

 QFile file( "test01.xml" );
 QXmlInputSource source( &file );

 QXmlSimpleReader reader;
 reader.setContentHandler( &handler );

 reader.parse( source );

 return 0;
}

/********************* read xml attribute*********************************/

   
        child11 boy
        child12 boy
   
   
        child21 boy
        child22 boy
   


#include
#include
#include
#include

void addElements(QList& list, const QDomElement& root)
{
 // add children to list
 QDomNode node = root.firstChild();
 for (; !node.isNull(); node = node.nextSibling())
 {
  if (!node.isElement()) continue;
  list.append(node.toElement());
  if (node.isText())
  {
   QString title = node.toText().data();
   //qDebug() << "root" <<  title;
  }
 }

 // go deeper
 node = root.firstChild();
 for (; !node.isNull(); node = node.nextSibling())
 {
  if (!node.isElement()) continue;
  addElements(list, node.toElement());
  if (node.isText())
  {
   QString title = node.toText().data();
   //qDebug() << "node" <<  title;
  }

 }
 QDomElement child = root.firstChildElement();
 while (!child.isNull())
 {
  qDebug() << "tag = " << child.tagName();
  if (child.hasAttribute("item") )
  {
   qDebug() << "Att = " << child.attribute("item");
  }

  if (child.hasAttribute("items") )
  {
   qDebug() << "Atts = " << child.attribute("items");
  }
  
  if (child.hasAttribute("item") )
  {
   if ( !child.isText() )
   {
    qDebug() << "Text = " << child.text() << "\n";
   }
    QString title = child.firstChildElement("child21").text();
    if (!title.isEmpty())
    {
    qDebug() << "dddddd = " << title << "\n";
    }
  }
  
  child = child.nextSiblingElement();
 }

}

int main(int argc, char** argv)
{
 if (argc != 2)
  qFatal("call with xml file as the argument");

 QFile file(argv[1]);
 if (!file.exists())
  qFatal("file \"%s\" does not exist", argv[1]);

 if (!file.open(QFile::ReadOnly | QFile::Text))
  qFatal("file \"%s\" cannot be read", argv[1]);

 QString errorStr;
 int errorLine;
 int errorColumn;
 QDomDocument doc;
 //if (!domDocument.setContent(device, true, &errorStr, &errorLine,&errorColumn)) {
 if (!doc.setContent(&file, true, &errorStr, &errorLine,&errorColumn))
  qFatal("file \"%s\" cannot be parsed", argv[1]);

 QList list;
 addElements(list, doc.documentElement());

 qDebug("file has %d elements", list.count());

 QList::const_iterator it    = list.begin();
 QList::const_iterator endIt = list.end();
 for (; it != endIt; ++it)
 {
  qDebug("%s", (*it).nodeName().toUtf8().data());
 }   

 return 0;
}