内容

• 公共函数
• 重实现公共函数
• 详细描述

QScxmlNullDataModel Class

The QScxmlNullDataModel class is the null data model for a Qt SCXML stateMachine . 更多...

头：	#include <QScxmlNullDataModel>
qmake:	QT += scxml
Since:	Qt 5.7
继承：	QScxmlDataModel

该类在 Qt 5.7 引入。

• 所有成员列表，包括继承成员

公共函数

	QScxmlNullDataModel (QObject * parent = nullptr)
virtual	~QScxmlNullDataModel ()

重实现公共函数

virtual void	evaluateAssignment (QScxmlExecutableContent::EvaluatorId id , bool * ok ) override
virtual void	evaluateForeach (QScxmlExecutableContent::EvaluatorId id , bool * ok , QScxmlDataModel::ForeachLoopBody * body ) override
virtual void	evaluateInitialization (QScxmlExecutableContent::EvaluatorId id , bool * ok ) override
virtual bool	evaluateToBool (QScxmlExecutableContent::EvaluatorId id , bool * ok ) override
virtual QString	evaluateToString (QScxmlExecutableContent::EvaluatorId id , bool * ok ) override
virtual QVariant	evaluateToVariant (QScxmlExecutableContent::EvaluatorId id , bool * ok ) override
virtual void	evaluateToVoid (QScxmlExecutableContent::EvaluatorId id , bool * ok ) override
virtual bool	hasScxmlProperty (const QString & name ) const override
virtual QVariant	scxmlProperty (const QString & name ) const override
virtual void	setScxmlEvent (const QScxmlEvent & event ) override
virtual bool	setScxmlProperty (const QString & name , const QVariant & value , const QString & context ) override
virtual bool	setup (const QVariantMap & initialDataValues ) override

详细描述

This class implements the null data model as described in the SCXML Specification - B.1 The Null Data Model . Using the value "null" 为 datamodel 属性在 <scxml> element means that there is no underlying data model, but some executable content, like In(...) or <log> can still be used.

另请参阅 QScxmlStateMachine and QScxmlDataModel .

成员函数文档编制

QScxmlNullDataModel:: QScxmlNullDataModel ( QObject * parent = nullptr)

Creates a new Qt SCXML null data model, with the parent object parent .

[virtual] QScxmlNullDataModel:: ~QScxmlNullDataModel ()

Destroys the data model.

[override virtual] void QScxmlNullDataModel:: evaluateAssignment ( QScxmlExecutableContent::EvaluatorId id , bool * ok )

重实现： QScxmlDataModel::evaluateAssignment (QScxmlExecutableContent::EvaluatorId id, bool *ok).

Throws an error and sets ok to false , because the null data model cannot evaluate assignments.

[override virtual] void QScxmlNullDataModel:: evaluateForeach ( QScxmlExecutableContent::EvaluatorId id , bool * ok , QScxmlDataModel::ForeachLoopBody * body )

重实现： QScxmlDataModel::evaluateForeach (QScxmlExecutableContent::EvaluatorId id, bool *ok, QScxmlDataModel::ForeachLoopBody *body).

Throws an error and sets ok to false , because the null data model cannot evaluate <foreach> blocks.

[override virtual] void QScxmlNullDataModel:: evaluateInitialization ( QScxmlExecutableContent::EvaluatorId id , bool * ok )

重实现： QScxmlDataModel::evaluateInitialization (QScxmlExecutableContent::EvaluatorId id, bool *ok).

Throws an error and sets ok to false , because the null data model cannot initialize data.

[override virtual] bool QScxmlNullDataModel:: evaluateToBool ( QScxmlExecutableContent::EvaluatorId id , bool * ok )

重实现： QScxmlDataModel::evaluateToBool (QScxmlExecutableContent::EvaluatorId id, bool *ok).

Evaluates the executable content pointed to by id and records in ok whether there was an error. Returns the result of the evaluation as a boolean value. The null data model can evaluate the instruction In(...) , so this might result in an actual value, rather than an error.

[override virtual] QString QScxmlNullDataModel:: evaluateToString ( QScxmlExecutableContent::EvaluatorId id , bool * ok )

重实现： QScxmlDataModel::evaluateToString (QScxmlExecutableContent::EvaluatorId id, bool *ok).

Evaluates the executable content pointed to by id and records in ok whether there was an error. Returns the result of the evaluation as a string. The null data model can evaluate the <log> element, so this might result in an actual value, rather than an error

[override virtual] QVariant QScxmlNullDataModel:: evaluateToVariant ( QScxmlExecutableContent::EvaluatorId id , bool * ok )

重实现： QScxmlDataModel::evaluateToVariant (QScxmlExecutableContent::EvaluatorId id, bool *ok).

Evaluates the executable content pointed to by id and records in ok whether there was an error. As this is the null data model, any evaluation will in fact result in an error, with ok 设为 false . Returns an empty QVariant .

[override virtual] void QScxmlNullDataModel:: evaluateToVoid ( QScxmlExecutableContent::EvaluatorId id , bool * ok )

重实现： QScxmlDataModel::evaluateToVoid (QScxmlExecutableContent::EvaluatorId id, bool *ok).

Evaluates the executable content pointed to by id and records in ok whether there was an error. As this is the null data model, any evaluation will in fact result in an error, with ok 设为 false .

[override virtual] bool QScxmlNullDataModel:: hasScxmlProperty (const QString & name ) const

重实现： QScxmlDataModel::hasScxmlProperty (const QString &name) const.

返回 false , because the null data model does not support properties.

[override virtual] QVariant QScxmlNullDataModel:: scxmlProperty (const QString & name ) const

重实现： QScxmlDataModel::scxmlProperty (const QString &name) const.

Returns an invalid variant, because the null data model does not support properties.

另请参阅 setScxmlProperty ().

[override virtual] void QScxmlNullDataModel:: setScxmlEvent (const QScxmlEvent & event )

重实现： QScxmlDataModel::setScxmlEvent (const QScxmlEvent &event).

Does not actually set the event , because the null data model does not handle events.

[override virtual] bool QScxmlNullDataModel:: setScxmlProperty (const QString & name , const QVariant & value , const QString & context )

重实现： QScxmlDataModel::setScxmlProperty (const QString &name, const QVariant &value, const QString &context).

返回 false , because the null data model does not support properties.

另请参阅 scxmlProperty ().

[override virtual] bool QScxmlNullDataModel:: setup (const QVariantMap & initialDataValues )

重实现： QScxmlDataModel::setup (const QVariantMap &initialDataValues).