QMetaMethod Class ReferenceThe QMetaMethod class provides meta-data about a member function. Далее... #include <QMetaMethod>
Открытые типы
Открытые функции
Подробное описаниеThe QMetaMethod class provides meta-data about a member function. A QMetaMethod has a methodType(), a signature(), 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, and Qt's Property System. Описание типов-членовenum QMetaMethod::AccessThis enum describes the access level of a method, following the conventions used in C++.
enum QMetaMethod::MethodType
Описание функций-членовAccess QMetaMethod::access () constReturns the access specification of this method (private, protected, or public). Signals are always protected, meaning that you can only emit them from the class or from a subclass. See also methodType(). bool QMetaMethod::invoke ( QObject * object, Qt::ConnectionType connectionType, QGenericReturnArgument returnValue, 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() ) constInvokes 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. The invocation can be either synchronous or asynchronous, depending on the connectionType:
The return value of this method call is placed in returnValue. If the invocation is asynchronous, the return value cannot be evaluated. You can pass up to ten arguments (val0, val1, val2, val3, val4, val5, val6, val7, val8, and val9) to this method call. QGenericArgument and QGenericReturnArgument are internal helper classes. Because signals and slots can be dynamically invoked, you must enclose the arguments using the Q_ARG() and Q_RETURN_ARG() macros. Q_ARG() takes a type name and a const reference of that type; Q_RETURN_ARG() takes a type name and a non-const reference. To asynchronously invoke the 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 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. Если вы пытаетесь использовать соединение через очередь и получаете сообщение об ошибке QMetaMethod::invoke: Unable to handle unregistered datatype 'MyType' call qRegisterMetaType() to register the data type before you call QMetaMethod::invoke(). 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 = 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)); QMetaObject::normalizedSignature() is used here to ensure that the format of the signature is what invoke() expects. E.g. extra whitespace is removed. If the "compute" slot does not take exactly one QString, one int and one double in the specified order, the call will fail. 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. The arguments must have the same type as the ones expected by the method, else, the behaviour is undefined. See also Q_ARG(), Q_RETURN_ARG(), qRegisterMetaType(), and QMetaObject::invokeMethod(). bool QMetaMethod::invoke ( QObject * object, QGenericReturnArgument returnValue, 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() ) constThis function overloads invoke(). This overload always invokes this method using the connection type Qt::AutoConnection. bool QMetaMethod::invoke ( QObject * object, Qt::ConnectionType connectionType, 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() ) constThis function overloads invoke(). This overload can be used if the return value of the member is of no interest. bool QMetaMethod::invoke ( QObject * object, 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() ) constThis function overloads invoke(). This overload invokes this method using the connection type Qt::AutoConnection and ignores return values. int QMetaMethod::methodIndex () constReturns this method's index. Эта функция была введена в Qt 4.6. MethodType QMetaMethod::methodType () constReturns the type of this method (signal, slot, or method). See also access(). QList<QByteArray> QMetaMethod::parameterNames () constReturns a list of parameter names. See also parameterTypes() and signature(). QList<QByteArray> QMetaMethod::parameterTypes () constReturns a list of parameter types. See also parameterNames() and signature(). const char * QMetaMethod::signature () constReturns the signature of this method (e.g., setValue(double)). See also parameterTypes() and parameterNames(). const char * QMetaMethod::tag () constReturns the tag associated with this method. Tags are special macros recognized by moc that make it possible to add extra information about a method. For the moment, moc doesn't support any special tags. const char * QMetaMethod::typeName () constReturns the return type of this method, or an empty string if the return type is void. |
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