Qt5 official demo example set 25 -- extending qml-methods example

All articles in this series can be viewed here in http://blog.csdn.net/cloud_castle/article/category/2123873

Link to qt5 official demo consumer set 24 -- extending qml-default property example

This example mainly introduces how to define functions in the qml type.

Person. h:

# Ifndef person_h # define person_h # include <qobject> class person: Public qobject // The basic person class is not changed, deleted boy and girl {q_object q_property (qstring name read name write setname) q_property (INT shoesize read shoesize write setshoesize) public: person (qobject * parent = 0); qstring name () const; void setname (const qstring &); int shoesize () const; void setshoesize (INT); Private: qstring m_name; int m_shoesize ;};# endif // person_h

Person. cpp:

#include "person.h"Person::Person(QObject *parent): QObject(parent), m_shoeSize(0){}QString Person::name() const{    return m_name;}void Person::setName(const QString &n){    m_name = n;}int Person::shoeSize() const{    return m_shoeSize;}void Person::setShoeSize(int s){    m_shoeSize = s;}

Birthdayparty. h:

# Ifndef birthdayparty_h # define birthdayparty_h # include <qobject> # include <qqmllistproperty> # include "person. H "class birthdayparty: Public qobject {q_object q_property (person * Host read host write sethost) q_property (qqmllistproperty <person> guests read guests) Public: birthdayparty (qobject * parent = 0 ); person * Host () const; void sethost (person *); qqmllistproperty <person> guests (); int guestcount ( ) Const; person * guest (INT) const ;//! [0] // a function q_invokable void invite (const qstring & name) is defined here; // to be able to call this function in qml, we need to use the macro q_invokable //! [0] // This macro allows this function to be called through the metadata system // otherwise, the compiler will complain about invite's undefined PRIVATE: person * m_host when calling it in qml; qlist <person *> m_guests;}; # endif // birthdayparty_h

Birthdayparty. cpp:

# Include "birthdayparty. H" birthdayparty: birthdayparty (qobject * parent): qobject (parent), m_host (0 ){}//! [0] person * birthdayparty: host () const {return m_host;} void birthdayparty: sethost (person * c) {m_host = C;} qqmllistproperty <person> birthdayparty :: guests () {return qqmllistproperty <person> (this, m_guests);} int birthdayparty: guestcount () const {return m_guests.count ();} person * birthdayparty :: guest (INT index) const {return m_guests.at (INDEX);} void birthdayparty: Invite (const qstring & name) // function implementation { Person * person = new person (this); person-> setname (name); m_guests.append (person );}//! [0]

Example. qml:

Import qtquick 2.0 import people 1.0 birthdayparty {Host: person {name: "Bob Jones" shoesize: 12} guests: [person {name: "Leo Hodges"}, person {Name: "Jack Smith"}, person {name: "Anne Brown"}] //! [0] component. oncompleted: Invite ("William green") // we need to call this function in a handler //! [0] // This is called when the component is complete}

Main. cpp:

#include <QCoreApplication>#include <QQmlEngine>#include <QQmlComponent>#include <QDebug>#include "birthdayparty.h"#include "person.h"int main(int argc, char ** argv){    QCoreApplication app(argc, argv);    qmlRegisterType<BirthdayParty>("People", 1,0, "BirthdayParty");    qmlRegisterType<Person>("People", 1,0, "Person");    QQmlEngine engine;    QQmlComponent component(&engine, QUrl("qrc:example.qml"));    BirthdayParty *party = qobject_cast<BirthdayParty *>(component.create());    if (party && party->host()) {        qWarning() << party->host()->name() << "is having a birthday!";        qWarning() << "They are inviting:";        for (int ii = 0; ii < party->guestCount(); ++ii)            qWarning() << "   " << party->guest(ii)->name();    } else {        qWarning() << component.errors();    }    return 0;}

Running result:

We can see that the first three guests exist as the guests attribute value initialization, while William green is "invited" only after the component is loaded.