Viadeo Twitter Google Bookmarks ! Facebook Digg del.icio.us MySpace Yahoo MyWeb Blinklist Netvouz Reddit Simpy StumbleUpon Bookmarks Windows Live Favorites 
Logo Documentation Qt ·  Page d'accueil  ·  Toutes les classes  ·  Classes principales  ·  Annotées  ·  Classes groupées  ·  Modules  ·  Fonctions  · 

QQmlPropertyMap Class

The QQmlPropertyMap class allows you to set key-value pairs that can be used in QML bindings. More...

 #include <QQmlPropertyMap>

Inherits: QObject.

QQmlPropertyMap is instantiated by QML element ExtendedAttributes

Public Functions

QQmlPropertyMap(QObject * parent = 0)
virtual ~QQmlPropertyMap()
void clear(const QString & key)
bool contains(const QString & key) const
int count() const
void insert(const QString & key, const QVariant & value)
bool isEmpty() const
QStringList keys() const
int size() const
QVariant value(const QString & key) const
QVariant & operator[](const QString & key)
QVariant operator[](const QString & key) const
  • 31 public functions inherited from QObject

Signals

void valueChanged(const QString & key, const QVariant & value)

Additional Inherited Members

  • 1 property inherited from QObject
  • 1 public slot inherited from QObject
  • 11 static public members inherited from QObject
  • 9 protected functions inherited from QObject

Detailed Description

The QQmlPropertyMap class allows you to set key-value pairs that can be used in QML bindings.

QQmlPropertyMap provides a convenient way to expose domain data to the UI layer. The following example shows how you might declare data in C++ and then access it in QML.

In the C++ file:

 // create our data
 QQmlPropertyMap ownerData;
 ownerData.insert("name", QVariant(QString("John Smith")));
 ownerData.insert("phone", QVariant(QString("555-5555")));

 // expose it to the UI layer
 QQuickView view;
 QQmlContext *ctxt = view.rootContext();
 ctxt->setContextProperty("owner", &ownerData);

 view.setSource(QUrl::fromLocalFile("main.qml"));
 view.show();

Then, in main.qml:

 Text { text: owner.name + " " + owner.phone }

The binding is dynamic - whenever a key's value is updated, anything bound to that key will be updated as well.

To detect value changes made in the UI layer you can connect to the valueChanged() signal. However, note that valueChanged() is NOT emitted when changes are made by calling insert() or clear() - it is only emitted when a value is updated from QML.

Note: It is not possible to remove keys from the map; once a key has been added, you can only modify or clear its associated value.

Member Function Documentation

QQmlPropertyMap::QQmlPropertyMap(QObject * parent = 0)

Constructs a bindable map with parent object parent.

QQmlPropertyMap::~QQmlPropertyMap() [virtual]

Destroys the bindable map.

void QQmlPropertyMap::clear(const QString & key)

Clears the value (if any) associated with key.

bool QQmlPropertyMap::contains(const QString & key) const

Returns true if the map contains key.

See also size().

int QQmlPropertyMap::count() const

This is an overloaded function.

Same as size().

void QQmlPropertyMap::insert(const QString & key, const QVariant & value)

Sets the value associated with key to value.

If the key doesn't exist, it is automatically created.

bool QQmlPropertyMap::isEmpty() const

Returns true if the map contains no keys; otherwise returns false.

See also size().

QStringList QQmlPropertyMap::keys() const

Returns the list of keys.

Keys that have been cleared will still appear in this list, even though their associated values are invalid QVariants.

int QQmlPropertyMap::size() const

Returns the number of keys in the map.

See also isEmpty() and count().

QVariant QQmlPropertyMap::value(const QString & key) const

Returns the value associated with key.

If no value has been set for this key (or if the value has been cleared), an invalid QVariant is returned.

void QQmlPropertyMap::valueChanged(const QString & key, const QVariant & value) [signal]

This signal is emitted whenever one of the values in the map is changed. key is the key corresponding to the value that was changed.

Note: valueChanged() is NOT emitted when changes are made by calling insert() or clear() - it is only emitted when a value is updated from QML.

QVariant & QQmlPropertyMap::operator[](const QString & key)

Returns the value associated with the key key as a modifiable reference.

If the map contains no item with key key, the function inserts an invalid QVariant into the map with key key, and returns a reference to it.

See also insert() and value().

QVariant QQmlPropertyMap::operator[](const QString & key) const

This is an overloaded function.

Same as value().

Cette page est une traduction d'une page de la documentation de Qt, écrite par Nokia Corporation and/or its subsidiary(-ies). Les éventuels problèmes résultant d'une mauvaise traduction ne sont pas imputables à Nokia. Qt 5.0-snapshot
Copyright © 2012 Developpez LLC. Tous droits réservés Developpez LLC. Aucune reproduction, même partielle, ne peut être faite de ce site et de l'ensemble de son contenu : textes, documents et images sans l'autorisation expresse de Developpez LLC. Sinon, vous encourez selon la loi jusqu'à 3 ans de prison et jusqu'à 300 000 E de dommages et intérêts. Cette page est déposée à la SACD.
Vous avez déniché une erreur ? Un bug ? Une redirection cassée ? Ou tout autre problème, quel qu'il soit ? Ou bien vous désirez participer à ce projet de traduction ? N'hésitez pas à nous contacter ou par MP !
 
 
 
 
Partenaires

Hébergement Web