QUntypedBindable is a uniform interface over bindable properties like
QProperty\<T\>
and
QObjectBindableProperty
of any type
T
.
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| 頭： | #include <QUntypedBindable> |
| CMake: |
find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core) |
| qmake: | QT += core |
| Since: | Qt 6.0 |
| 繼承者： | QBindable |
| QUntypedBindable () | |
| QUntypedBindable (Property * property ) | |
| QPropertyNotifier | addNotifier (Functor f ) |
| QUntypedPropertyBinding | binding () const |
| bool | hasBinding () const |
| bool | isReadOnly () const |
| bool | isValid () const |
| QUntypedPropertyBinding | makeBinding (const QPropertyBindingSourceLocation & location = QT_PROPERTY_DEFAULT_BINDING_LOCATION) const |
| QMetaType | metaType () const |
| QPropertyChangeHandler<Functor> | onValueChanged (Functor f ) const |
| bool | setBinding (const QUntypedPropertyBinding & binding ) |
| QPropertyChangeHandler<Functor> | subscribe (Functor f ) const |
| QUntypedPropertyBinding | takeBinding () |
QUntypedBindable is a fully type-erased generic interface to wrap bindable properties. You can use it to interact with properties without knowing their type nor caring what kind of bindable property they are (e.g. QProperty or QObjectBindableProperty ). For most use cases, using QBindable <T> (which is generic over the property implementation but has a fixed type) should be preferred.
[constexpr]
QUntypedBindable::
QUntypedBindable
()
Default-constructs a QUntypedBindable. It is in an invalid state.
另請參閱 isValid ().
Constructs a QUntypedBindable from the property property . If Property is const, the QUntypedBindable will be read only. If property is null, the QUntypedBindable will be invalid.
另請參閱 isValid () 和 isReadOnly ().
Installs
f
as a change handler. Whenever the underlying property changes,
f
will be called, as long as the returned
QPropertyNotifier
and the property are kept alive.
This method is in some cases easier to use than onValueChanged (), as the returned object is not a template. It can therefore more easily be stored, e.g. as a member in a class.
另請參閱 onValueChanged () 和 subscribe ().
Returns the underlying property's binding if there is any, or a default constructed QUntypedPropertyBinding otherwise.
另請參閱 setBinding () 和 hasBinding ().
返迴
true
if the underlying property has a binding.
[since 6.1]
bool
QUntypedBindable::
isReadOnly
() const
返迴 true 若 QUntypedBindable is read-only.
This function was introduced in Qt 6.1.
返迴 true 若 QUntypedBindable is valid. Methods called on an invalid QUntypedBindable generally have no effect, unless otherwise noted.
Creates a binding returning the underlying properties' value, using a specified source location .
[since 6.2]
QMetaType
QUntypedBindable::
metaType
() const
Returns the metatype of the property from which the QUntypedBindable was created. If the bindable is invalid, an invalid metatype will be returned.
This function was introduced in Qt 6.2.
另請參閱 isValid ().
Installs
f
as a change handler. Whenever the underlying property changes,
f
will be called, as long as the returned
QPropertyChangeHandler
and the property are kept alive. On each value change, the handler is either called immediately, or deferred, depending on the context.
另請參閱 onValueChanged() and subscribe ().
Sets the underlying property's binding to binding . This does not have any effect if the QUntypedBindable is read-only, null or if binding 's type does match the underlying property's type.
返迴
true
when the binding was successfully set.
另請參閱 binding ().
Behaves like a call to
f
followed by
onValueChanged(f)
,
另請參閱 onValueChanged ().
[since 6.1]
QUntypedPropertyBinding
QUntypedBindable::
takeBinding
()
Removes the currently set binding from the property and returns it. Returns a default-constructed QUntypedPropertyBinding if no binding is set.
This function was introduced in Qt 6.1.