\inmodule QtCore More...

#include <qmetaobject.h>

Inheritance diagram for QMetaMethod:

Collaboration diagram for QMetaMethod:

Classes
struct	Data

Public Types
enum	Access { Private , Protected , Public }
	This enum describes the access level of a method, following the conventions used in C++. More...

enum	MethodType { Method , Signal , Slot , Constructor }
	\value Method The function is a plain member function. More...

enum	Attributes { Compatibility = 0x1 , Cloned = 0x2 , Scriptable = 0x4 }

Public Member Functions
constexpr	QMetaMethod ()

QByteArray	methodSignature () const

QByteArray	name () const

QByteArrayView	nameView () const

const char *	typeName () const
	Returns the return type name of this method.

int	returnType () const

QMetaType	returnMetaType () const

int	parameterCount () const

int	parameterType (int index) const

QMetaType	parameterMetaType (int index) const

void	getParameterTypes (int *types) const

QList< QByteArray >	parameterTypes () const
	Returns a list of parameter types.

QByteArray	parameterTypeName (int index) const

QList< QByteArray >	parameterNames () const
	Returns a list of parameter names.

const char *	tag () const
	Returns the tag associated with this method.

Access	access () const
	Returns the access specification of this method (private, protected, or public).

MethodType	methodType () const
	Returns the type of this method (signal, slot, or method).

int	attributes () const

int	methodIndex () const

int	relativeMethodIndex () const

int	revision () const

bool	isConst () const

const QMetaObject *	enclosingMetaObject () const

bool	invoke (QObject *object, Qt::ConnectionType connectionType, QGenericReturnArgument returnValue, QGenericArgument val0=QGenericArgument(nullptr), QGenericArgument val1=QGenericArgument(), QGenericArgument val2=QGenericArgument(), QGenericArgument val3=QGenericArgument(), QGenericArgument val4=QGenericArgument(), QGenericArgument val5=QGenericArgument(), QGenericArgument val6=QGenericArgument(), QGenericArgument val7=QGenericArgument(), QGenericArgument val8=QGenericArgument(), QGenericArgument val9=QGenericArgument()) const
	\obsolete [6.5] Please use the variadic overload of this function

bool	invoke (QObject *object, QGenericReturnArgument returnValue, QGenericArgument val0=QGenericArgument(nullptr), QGenericArgument val1=QGenericArgument(), QGenericArgument val2=QGenericArgument(), QGenericArgument val3=QGenericArgument(), QGenericArgument val4=QGenericArgument(), QGenericArgument val5=QGenericArgument(), QGenericArgument val6=QGenericArgument(), QGenericArgument val7=QGenericArgument(), QGenericArgument val8=QGenericArgument(), QGenericArgument val9=QGenericArgument()) const

bool	invoke (QObject *object, Qt::ConnectionType connectionType, QGenericArgument val0, QGenericArgument val1=QGenericArgument(), QGenericArgument val2=QGenericArgument(), QGenericArgument val3=QGenericArgument(), QGenericArgument val4=QGenericArgument(), QGenericArgument val5=QGenericArgument(), QGenericArgument val6=QGenericArgument(), QGenericArgument val7=QGenericArgument(), QGenericArgument val8=QGenericArgument(), QGenericArgument val9=QGenericArgument()) const

bool	invoke (QObject *object, QGenericArgument val0, QGenericArgument val1=QGenericArgument(), QGenericArgument val2=QGenericArgument(), QGenericArgument val3=QGenericArgument(), QGenericArgument val4=QGenericArgument(), QGenericArgument val5=QGenericArgument(), QGenericArgument val6=QGenericArgument(), QGenericArgument val7=QGenericArgument(), QGenericArgument val8=QGenericArgument(), QGenericArgument val9=QGenericArgument()) const

bool	invokeOnGadget (void *gadget, QGenericReturnArgument returnValue, QGenericArgument val0=QGenericArgument(nullptr), QGenericArgument val1=QGenericArgument(), QGenericArgument val2=QGenericArgument(), QGenericArgument val3=QGenericArgument(), QGenericArgument val4=QGenericArgument(), QGenericArgument val5=QGenericArgument(), QGenericArgument val6=QGenericArgument(), QGenericArgument val7=QGenericArgument(), QGenericArgument val8=QGenericArgument(), QGenericArgument val9=QGenericArgument()) const

bool	invokeOnGadget (void *gadget, QGenericArgument val0, QGenericArgument val1=QGenericArgument(), QGenericArgument val2=QGenericArgument(), QGenericArgument val3=QGenericArgument(), QGenericArgument val4=QGenericArgument(), QGenericArgument val5=QGenericArgument(), QGenericArgument val6=QGenericArgument(), QGenericArgument val7=QGenericArgument(), QGenericArgument val8=QGenericArgument(), QGenericArgument val9=QGenericArgument()) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. \obsolete [6.5] Please use the variadic overload of this function.

template<typename ReturnArg, typename... Args>
QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... >	invoke (QObject *obj, Qt::ConnectionType c, QTemplatedMetaMethodReturnArgument< ReturnArg > r, Args &&... arguments) const

template<typename... Args>
QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... >	invoke (QObject *obj, Qt::ConnectionType c, Args &&... arguments) const

template<typename ReturnArg, typename... Args>
QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... >	invoke (QObject *obj, QTemplatedMetaMethodReturnArgument< ReturnArg > r, Args &&... arguments) const

template<typename... Args>
QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... >	invoke (QObject *obj, Args &&... arguments) const

template<typename ReturnArg, typename... Args>
QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... >	invokeOnGadget (void *gadget, QTemplatedMetaMethodReturnArgument< ReturnArg > r, Args &&... arguments) const

template<typename... Args>
QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... >	invokeOnGadget (void *gadget, Args &&... arguments) const

bool	isValid () const

Static Public Member Functions
template<typename PointerToMemberFunction>
static QMetaMethod	fromSignal (PointerToMemberFunction signal)

Protected Attributes
const QMetaObject *	mobj

Data	data

Friends
struct	QMetaObject

struct	QMetaObjectPrivate

class	QObject

bool	comparesEqual (const QMetaMethod &lhs, const QMetaMethod &rhs) noexcept

Related Symbols
(Note that these are not member symbols.)
QByteArray	signature () const
	\macro Q_METAMETHOD_INVOKE_MAX_ARGS

Detailed Description

\inmodule QtCore

The QMetaMethod class provides meta-data about a member function.

\compares equality

A QMetaMethod has a methodType(), a methodSignature(), a list of parameterTypes() and parameterNames(), a return typeName(), a tag(), and an access() specifier. You can use invoke() to invoke the method on an arbitrary QObject.

See also: QMetaObject, QMetaEnum, QMetaProperty, {Qt's Property System}

Definition at line 18 of file qmetaobject.h.

Member Enumeration Documentation

◆ Access

enum QMetaMethod::Access

This enum describes the access level of a method, following the conventions used in C++.

\value Private \value Protected \value Public

Enumerator
Private
Protected
Public

Definition at line 37 of file qmetaobject.h.

◆ Attributes

enum QMetaMethod::Attributes

\value Compatibility \value Cloned \value Scriptable

Enumerator
Compatibility
Cloned
Scriptable

Definition at line 41 of file qmetaobject.h.

◆ MethodType

enum QMetaMethod::MethodType

\value Method The function is a plain member function.

\value Signal The function is a signal. \value Slot The function is a slot. \value Constructor The function is a constructor.

Enumerator
Method
Signal
Slot
Constructor

Definition at line 39 of file qmetaobject.h.

Constructor & Destructor Documentation

◆ QMetaMethod()

QMetaMethod::QMetaMethod ( )

inlineconstexpr

Definition at line 21 of file qmetaobject.h.

Member Function Documentation

◆ access()

QMetaMethod::Access QMetaMethod::access ( ) const

Returns the access specification of this method (private, protected, or public).

Note: Signals are always public, but you should regard that as an implementation detail. It is almost always a bad idea to emit a signal from outside its class.

See also: methodType()

Definition at line 2416 of file qmetaobject.cpp.

◆ attributes()

int QMetaMethod::attributes ( ) const

Definition at line 2332 of file qmetaobject.cpp.

◆ enclosingMetaObject()

const QMetaObject * QMetaMethod::enclosingMetaObject ( ) const

inline

Definition at line 48 of file qmetaobject.h.

◆ fromSignal()

template<typename PointerToMemberFunction>

static QMetaMethod QMetaMethod::fromSignal ( PointerToMemberFunction signal )

inlinestatic

Since: 5.0

Returns the meta-method that corresponds to the given signal, or an invalid QMetaMethod if signal is {nullptr} or not a signal of the class.

Example:

QMetaMethod destroyedSignal = QMetaMethod::fromSignal(&QObject::destroyed);

Definition at line 214 of file qmetaobject.h.

◆ getParameterTypes()

void QMetaMethod::getParameterTypes ( int * types ) const

Since: 5.0

Gets the parameter types of this method. The storage for types must be able to hold parameterCount() items.

See also: parameterCount(), returnType(), parameterType()

Definition at line 2230 of file qmetaobject.cpp.

◆ invoke() [1/8]

template<typename... Args>

QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... > QMetaMethod::invoke	(	QObject *	obj,
		Args &&...	arguments ) const

inline

Since: 6.5

Invokes this method on the object object. Returns true if the member could be invoked. Returns false if there is no such member or the parameters did not match.

For the overloads with a QTemplatedMetaMethodReturnArgument parameter, the return value of the member function call is placed in ret. For the overloads without such a member, the return value of the called function (if any) will be discarded. QTemplatedMetaMethodReturnArgument is an internal type you should not use directly. Instead, use the qReturnArg() function.

The overloads with a Qt::ConnectionType type parameter allow explicitly selecting whether the invocation will be synchronous or not:

\list

If type is Qt::DirectConnection, the member will be invoked immediately in the current thread.

If type is Qt::QueuedConnection, a QEvent will be sent and the member is invoked as soon as the application enters the event loop in the thread the obj was created in or was moved to.

If type is Qt::BlockingQueuedConnection, the method will be invoked in the same way as for Qt::QueuedConnection, except that the current thread will block until the event is delivered. Using this connection type to communicate between objects in the same thread will lead to deadlocks.

If type is Qt::AutoConnection, the member is invoked synchronously if obj lives in the same thread as the caller; otherwise it will invoke the member asynchronously. This is the behavior of the overloads that do not have the type parameter. \endlist

To asynchronously invoke the \l{QPushButton::animateClick()}{animateClick()} slot on a QPushButton:

int methodIndex = pushButton->metaObject()->indexOfMethod("animateClick()");
QMetaMethod method = metaObject->method(methodIndex);
method.invoke(pushButton, Qt::QueuedConnection);

With asynchronous method invocations, the parameters must be copyable types, because Qt needs to copy the arguments to store them in an event behind the scenes. Since Qt 6.5, this function automatically registers the types being used; however, as a side-effect, it is not possible to make calls using types that are only forward-declared. Additionally, it is not possible to make asynchronous calls that use references to non-const-qualified types as parameters either.

To synchronously invoke the compute(QString, int, double) slot on some arbitrary object obj retrieve its return value:

QString retVal;
QByteArray normalizedSignature = QMetaObject::normalizedSignature("compute(QString, int, double)");
int methodIndex = obj->metaObject()->indexOfMethod(normalizedSignature);
QMetaMethod method = obj->metaObject()->method(methodIndex);
method.invoke(obj, Qt::DirectConnection, qReturnArg(retVal),
              QString("sqrt"), 42, 9.7);

If the "compute" slot does not take exactly one \l QString, one int, and one double in the specified order, the call will fail. Note how it was necessary to be explicit about the type of the QString, as the character literal is not exactly the right type to match. If the method instead took a \l QByteArray, a \l qint64, and a {long double}, the call would need to be written as:

QString retVal;
QByteArray normalizedSignature = QMetaObject::normalizedSignature("compute(QByteArray, qint64, long double)");
int methodIndex = obj->metaObject()->indexOfMethod(normalizedSignature);
QMetaMethod method = obj->metaObject()->method(methodIndex);
method.invoke(obj, Qt::DirectConnection, qReturnArg(retVal),
              QByteArray("sqrt"), qint64(42), 9.7L);

The same call can be executed using the Q_ARG() and Q_RETURN_ARG() macros, as in:

QString retVal;
QByteArray normalizedSignature = QMetaObject::normalizedSignature("compute(QString, int, double)");
int methodIndex = obj->metaObject()->indexOfMethod(normalizedSignature);
QMetaMethod method = obj->metaObject()->method(methodIndex);
method.invoke(obj,
              Qt::DirectConnection,
              Q_RETURN_ARG(QString, retVal),
              Q_ARG(QString, "sqrt"),
              Q_ARG(int, 42),
              Q_ARG(double, 9.7));

Warning: this method will not test the validity of the arguments: object must be an instance of the class of the QMetaObject of which this QMetaMethod has been constructed with.

See also: Q_ARG(), Q_RETURN_ARG(), qRegisterMetaType(), QMetaObject::invokeMethod()

Definition at line 182 of file qmetaobject.h.

◆ invoke() [2/8]

template<typename... Args>

QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... > QMetaMethod::invoke	(	QObject *	obj,
		Qt::ConnectionType	c,
		Args &&...	arguments ) const

inline

Definition at line 160 of file qmetaobject.h.

◆ invoke() [3/8]

template<typename ReturnArg, typename... Args>

QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... > QMetaMethod::invoke	(	QObject *	obj,
		Qt::ConnectionType	c,
		QTemplatedMetaMethodReturnArgument< ReturnArg >	r,
		Args &&...	arguments ) const

inline

Definition at line 146 of file qmetaobject.h.

◆ invoke() [4/8]

template<typename ReturnArg, typename... Args>

QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... > QMetaMethod::invoke	(	QObject *	obj,
		QTemplatedMetaMethodReturnArgument< ReturnArg >	r,
		Args &&...	arguments ) const

inline

Definition at line 171 of file qmetaobject.h.

◆ invoke() [5/8]

bool QMetaMethod::invoke	(	QObject *	object,
		QGenericArgument	val0,
		QGenericArgument	val1 = QGenericArgument(),
		QGenericArgument	val2 = QGenericArgument(),
		QGenericArgument	val3 = QGenericArgument(),
		QGenericArgument	val4 = QGenericArgument(),
		QGenericArgument	val5 = QGenericArgument(),
		QGenericArgument	val6 = QGenericArgument(),
		QGenericArgument	val7 = QGenericArgument(),
		QGenericArgument	val8 = QGenericArgument(),
		QGenericArgument	val9 = QGenericArgument() ) const

inline

Definition at line 96 of file qmetaobject.h.

◆ invoke() [6/8]

bool QMetaMethod::invoke	(	QObject *	object,
		QGenericReturnArgument	returnValue,
		QGenericArgument	val0 = QGenericArgument(nullptr),
		QGenericArgument	val1 = QGenericArgument(),
		QGenericArgument	val2 = QGenericArgument(),
		QGenericArgument	val3 = QGenericArgument(),
		QGenericArgument	val4 = QGenericArgument(),
		QGenericArgument	val5 = QGenericArgument(),
		QGenericArgument	val6 = QGenericArgument(),
		QGenericArgument	val7 = QGenericArgument(),
		QGenericArgument	val8 = QGenericArgument(),
		QGenericArgument	val9 = QGenericArgument() ) const

inline

Definition at line 64 of file qmetaobject.h.

◆ invoke() [7/8]

bool QMetaMethod::invoke	(	QObject *	object,
		Qt::ConnectionType	connectionType,
		QGenericArgument	val0,
		QGenericArgument	val1 = QGenericArgument(),
		QGenericArgument	val2 = QGenericArgument(),
		QGenericArgument	val3 = QGenericArgument(),
		QGenericArgument	val4 = QGenericArgument(),
		QGenericArgument	val5 = QGenericArgument(),
		QGenericArgument	val6 = QGenericArgument(),
		QGenericArgument	val7 = QGenericArgument(),
		QGenericArgument	val8 = QGenericArgument(),
		QGenericArgument	val9 = QGenericArgument() ) const

inline

Definition at line 80 of file qmetaobject.h.

◆ invoke() [8/8]

bool QMetaMethod::invoke	(	QObject *	object,
		Qt::ConnectionType	connectionType,
		QGenericReturnArgument	returnValue,
		QGenericArgument	val0 = QGenericArgument(nullptr),
		QGenericArgument	val1 = QGenericArgument(),
		QGenericArgument	val2 = QGenericArgument(),
		QGenericArgument	val3 = QGenericArgument(),
		QGenericArgument	val4 = QGenericArgument(),
		QGenericArgument	val5 = QGenericArgument(),
		QGenericArgument	val6 = QGenericArgument(),
		QGenericArgument	val7 = QGenericArgument(),
		QGenericArgument	val8 = QGenericArgument(),
		QGenericArgument	val9 = QGenericArgument() ) const

\obsolete [6.5] Please use the variadic overload of this function

Invokes this method on the object object. Returns true if the member could be invoked. Returns false if there is no such member or the parameters did not match.

See the variadic invokeMethod() function for more information. This function should behave the same way as that one, with the following limitations:

\list

The number of parameters is limited to 10.
Parameter names may need to be an exact string match.
Meta types are not automatically registered. \endlist

With asynchronous method invocations, the parameters must be of types that are known to Qt's meta-object system, because Qt needs to copy the arguments to store them in an event behind the scenes. If you try to use a queued connection and get the error message

QMetaMethod::invoke: Unable to handle unregistered datatype 'MyType'

call qRegisterMetaType() to register the data type before you call QMetaMethod::invoke().

Warning: In addition to the limitations of the variadic invoke() overload, the arguments must have the same type as the ones expected by the method, else, the behavior is undefined.

See also: Q_ARG(), Q_RETURN_ARG(), qRegisterMetaType(), QMetaObject::invokeMethod()

Definition at line 2579 of file qmetaobject.cpp.

◆ invokeOnGadget() [1/4]

template<typename... Args>

QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... > QMetaMethod::invokeOnGadget	(	void *	gadget,
		Args &&...	arguments ) const

inline

Since: 6.5

Invokes this method on a Q_GADGET. Returns true if the member could be invoked. Returns false if there is no such member or the parameters did not match.

The pointer gadget must point to an instance of the gadget class.

The invocation is always synchronous.

For the overload with a QTemplatedMetaMethodReturnArgument parameter, the return value of the member function call is placed in ret. For the overload without it, the return value of the called function (if any) will be discarded. QTemplatedMetaMethodReturnArgument is an internal type you should not use directly. Instead, use the qReturnArg() function.

Warning: this method will not test the validity of the arguments: gadget must be an instance of the class of the QMetaObject of which this QMetaMethod has been constructed with.

See also: Q_ARG(), Q_RETURN_ARG(), qRegisterMetaType(), QMetaObject::invokeMethod()

Definition at line 206 of file qmetaobject.h.

◆ invokeOnGadget() [2/4]

bool QMetaMethod::invokeOnGadget	(	void *	gadget,
		QGenericArgument	val0 = QGenericArgument(0),
		QGenericArgument	val1 = QGenericArgument(),
		QGenericArgument	val2 = QGenericArgument(),
		QGenericArgument	val3 = QGenericArgument(),
		QGenericArgument	val4 = QGenericArgument(),
		QGenericArgument	val5 = QGenericArgument(),
		QGenericArgument	val6 = QGenericArgument(),
		QGenericArgument	val7 = QGenericArgument(),
		QGenericArgument	val8 = QGenericArgument(),
		QGenericArgument	val9 = QGenericArgument() ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. \obsolete [6.5] Please use the variadic overload of this function.

Since: 5.5

This overload invokes this method for a gadget and ignores return values.

Definition at line 123 of file qmetaobject.h.

◆ invokeOnGadget() [3/4]

bool QMetaMethod::invokeOnGadget	(	void *	gadget,
		QGenericReturnArgument	returnValue,
		QGenericArgument	val0 = QGenericArgument(nullptr),
		QGenericArgument	val1 = QGenericArgument(),
		QGenericArgument	val2 = QGenericArgument(),
		QGenericArgument	val3 = QGenericArgument(),
		QGenericArgument	val4 = QGenericArgument(),
		QGenericArgument	val5 = QGenericArgument(),
		QGenericArgument	val6 = QGenericArgument(),
		QGenericArgument	val7 = QGenericArgument(),
		QGenericArgument	val8 = QGenericArgument(),
		QGenericArgument	val9 = QGenericArgument() ) const

Since: 5.5 \obsolete [6.5] Please use the variadic overload of this function

Invokes this method on a Q_GADGET. Returns true if the member could be invoked. Returns false if there is no such member or the parameters did not match.

See the variadic invokeMethod() function for more information. This function should behave the same way as that one, with the following limitations:

\list

The number of parameters is limited to 10.
Parameter names may need to be an exact string match.
Meta types are not automatically registered. \endlist

Warning: In addition to the limitations of the variadic invoke() overload, the arguments must have the same type as the ones expected by the method, else, the behavior is undefined.

See also: Q_ARG(), Q_RETURN_ARG(), qRegisterMetaType(), QMetaObject::invokeMethod()

Definition at line 2956 of file qmetaobject.cpp.

◆ invokeOnGadget() [4/4]

template<typename ReturnArg, typename... Args>

QtPrivate::Invoke::IfNotOldStyleArgs< bool, Args... > QMetaMethod::invokeOnGadget	(	void *	gadget,
		QTemplatedMetaMethodReturnArgument< ReturnArg >	r,
		Args &&...	arguments ) const

inline

Definition at line 193 of file qmetaobject.h.

◆ isConst()

bool QMetaMethod::isConst ( ) const

Since: 6.2

Returns whether the method is const qualified.

Note: This method might erroneously return false for a const method if it belongs to a library compiled against an older version of Qt.

Definition at line 2397 of file qmetaobject.cpp.

◆ isValid()

bool QMetaMethod::isValid ( ) const

inline

Since: 5.0

Returns true if this method is valid (can be introspected and invoked), otherwise returns false.

Definition at line 211 of file qmetaobject.h.

◆ methodIndex()

int QMetaMethod::methodIndex ( ) const

Since: 4.6

Returns this method's index.

Definition at line 2344 of file qmetaobject.cpp.

◆ methodSignature()

QByteArray QMetaMethod::methodSignature ( ) const

Since: 5.0

Returns the signature of this method (e.g., {setValue(double)}).

See also: parameterTypes(), parameterNames()

Definition at line 2098 of file qmetaobject.cpp.

◆ methodType()

QMetaMethod::MethodType QMetaMethod::methodType ( ) const

Returns the type of this method (signal, slot, or method).

See also: access()

Definition at line 2428 of file qmetaobject.cpp.

◆ name()

QByteArray QMetaMethod::name ( ) const

Since: 5.0

Returns the name of this method.

See also: methodSignature(), parameterCount()

Definition at line 2112 of file qmetaobject.cpp.

◆ nameView()

QByteArrayView QMetaMethod::nameView ( ) const

Since: 6.9

Returns the name of this method. The returned QByteArrayView is valid as long as the meta-object of the class to which the method belongs is valid.

See also: name

Definition at line 2129 of file qmetaobject.cpp.

◆ parameterCount()

int QMetaMethod::parameterCount ( ) const

Since: 5.0

Returns the number of parameters of this method.

See also: parameterType(), parameterNames()

Definition at line 2173 of file qmetaobject.cpp.

◆ parameterMetaType()

QMetaType QMetaMethod::parameterMetaType ( int index ) const

Since: 6.0

Returns the metatype of the parameter at the given index.

If the index is smaller than zero or larger than parameterCount(), an invalid QMetaType is returned.

See also: parameterCount(), returnMetaType(), QMetaType

Definition at line 2205 of file qmetaobject.cpp.

◆ parameterNames()

QList< QByteArray > QMetaMethod::parameterNames ( ) const

Returns a list of parameter names.

See also: parameterTypes(), methodSignature()

Definition at line 2269 of file qmetaobject.cpp.

◆ parameterType()

int QMetaMethod::parameterType ( int index ) const

Since: 5.0

Returns the type of the parameter at the given index.

The return value is one of the types that are registered with QMetaType, or QMetaType::UnknownType if the type is not registered.

See also: parameterCount(), parameterMetaType(), returnType(), QMetaType

Definition at line 2190 of file qmetaobject.cpp.

◆ parameterTypeName()

QByteArray QMetaMethod::parameterTypeName ( int index ) const

Since: 6.0 Returns the name of the type at position index If there is no parameter at index, returns an empty QByteArray

See also: parameterNames()

Definition at line 2256 of file qmetaobject.cpp.

◆ parameterTypes()

QList< QByteArray > QMetaMethod::parameterTypes ( ) const

Returns a list of parameter types.

See also: parameterNames(), methodSignature()

Definition at line 2242 of file qmetaobject.cpp.

◆ relativeMethodIndex()

int QMetaMethod::relativeMethodIndex ( ) const

Since: 6.0

Returns this method's local index inside.

Definition at line 2356 of file qmetaobject.cpp.

◆ returnMetaType()

QMetaType QMetaMethod::returnMetaType ( ) const

Since: 6.0

Returns the return type of this method.

See also: parameterMetaType(), QMetaType, typeName()

Definition at line 2155 of file qmetaobject.cpp.

◆ returnType()

int QMetaMethod::returnType ( ) const

Since: 5.0

Returns the return type of this method.

The return value is one of the types that are registered with QMetaType, or QMetaType::UnknownType if the type is not registered.

See also: parameterType(), QMetaType, typeName(), returnMetaType()

Definition at line 2144 of file qmetaobject.cpp.

◆ revision()

int QMetaMethod::revision ( ) const

Since: 5.1 Returns the method revision if one was specified by Q_REVISION, otherwise returns 0. Since Qt 6.0, non-zero values are encoded and can be decoded using QTypeRevision::fromEncodedVersion().

Definition at line 2370 of file qmetaobject.cpp.

◆ tag()

const char * QMetaMethod::tag ( ) const

Returns the tag associated with this method.

Tags are special macros recognized by moc that make it possible to add extra information about a method.

Tag information can be added in the following way in the function declaration:

    // In the class MainWindow declaration
    #ifndef Q_MOC_RUN
    // define the tag text as empty, so the compiler doesn't see it
    #  define MY_CUSTOM_TAG
    #endif
    ...
    private slots:
        MY_CUSTOM_TAG void testFunc();

and the information can be accessed by using:

    MainWindow win;
    win.show();
 
    int functionIndex = win.metaObject()->indexOfSlot("testFunc()");
    QMetaMethod mm = win.metaObject()->method(functionIndex);
    qDebug() << mm.tag(); // prints MY_CUSTOM_TAG

For the moment, moc will extract and record all tags, but it will not handle any of them specially. You can use the tags to annotate your methods differently, and treat them according to the specific needs of your application.

Note: moc expands preprocessor macros, so it is necessary to surround the definition with #ifndef Q_MOC_RUN, as shown in the example above.

Definition at line 2321 of file qmetaobject.cpp.

◆ typeName()

const char * QMetaMethod::typeName ( ) const

Returns the return type name of this method.

If this method is a constructor, this function returns an empty string (constructors have no return types).

Note: In Qt 7, this function will return a null pointer for constructors.

See also: returnType(), QMetaType::type()

Definition at line 2286 of file qmetaobject.cpp.

Friends And Related Symbol Documentation

◆ comparesEqual

bool comparesEqual	(	const QMetaMethod &	lhs,
		const QMetaMethod &	rhs )

friend

Definition at line 258 of file qmetaobject.h.

◆ QMetaObject

friend struct QMetaObject

friend

Definition at line 253 of file qmetaobject.h.

◆ QMetaObjectPrivate

friend struct QMetaObjectPrivate

friend

Definition at line 254 of file qmetaobject.h.

◆ QObject

friend class QObject

friend

Definition at line 255 of file qmetaobject.h.

◆ signature()

QByteArray signature ( ) const

\macro Q_METAMETHOD_INVOKE_MAX_ARGS

Equals maximum number of arguments available for execution of the method via QMetaMethod::invoke()

Definition at line 1905 of file qmetaobject.cpp.

Member Data Documentation

◆ data

Data QMetaMethod::data

protected

Definition at line 252 of file qmetaobject.h.

◆ mobj

const QMetaObject* QMetaMethod::mobj

protected

Definition at line 251 of file qmetaobject.h.

The documentation for this class was generated from the following files:

qtbase/src/corelib/kernel/qmetaobject.h (da799c20d763b5534152dca52fef12fda875acc2)
qtbase/src/corelib/kernel/qmetaobject.cpp (4dcff4ed6d24e6aa061e145bb9de9ff93351a2b1)

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◆ QMetaMethod()

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◆ access()

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◆ invoke() [1/8]

◆ invoke() [2/8]

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◆ QMetaObject

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◆ mobj