The QScxmlNullDataModel class is the null data model for a Qt SCXML stateMachine 更多...
| 頭: | #include <QScxmlNullDataModel> |
| qmake: | QT += scxml |
| Since: | Qt 5.7 |
| 繼承: | QScxmlDataModel |
| QScxmlNullDataModel (QObject * parent = nullptr) | |
| ~QScxmlNullDataModel () |
| virtual void | evaluateAssignment (QScxmlExecutableContent::EvaluatorId id , bool * ok ) |
| virtual void | evaluateForeach (QScxmlExecutableContent::EvaluatorId id , bool * ok , ForeachLoopBody * body ) |
| virtual void | evaluateInitialization (QScxmlExecutableContent::EvaluatorId id , bool * ok ) |
| virtual bool | evaluateToBool (QScxmlExecutableContent::EvaluatorId id , bool * ok ) |
| virtual QString | evaluateToString (QScxmlExecutableContent::EvaluatorId id , bool * ok ) |
| virtual QVariant | evaluateToVariant (QScxmlExecutableContent::EvaluatorId id , bool * ok ) |
| virtual void | evaluateToVoid (QScxmlExecutableContent::EvaluatorId id , bool * ok ) |
| virtual bool | hasScxmlProperty (const QString & name ) const |
| virtual QVariant | scxmlProperty (const QString & name ) const |
| virtual void | setScxmlEvent (const QScxmlEvent & event ) |
| virtual bool | setScxmlProperty (const QString & name , const QVariant & value , const QString & context ) |
| virtual bool | setup (const QVariantMap & initialDataValues ) |
The QScxmlNullDataModel class is the null data model for a Qt SCXML stateMachine
This class implements the null data model as described in the
SCXML Specification - B.1 The Null Data Model
. Using the value
"null"
為
datamodel
屬性在
<scxml>
element means that there is no underlying data model, but some executable content, like
In(...)
or
<log>
can still be used.
另請參閱 QScxmlStateMachine and QScxmlDataModel .
Creates a new Qt SCXML null data model, with the parent object parent .
Destroys the data model.
[虛擬]
void
QScxmlNullDataModel::
evaluateAssignment
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
)
重實現自 QScxmlDataModel::evaluateAssignment ().
Throws an error and sets
ok
to
false
, because the null data model cannot evaluate assignments.
[虛擬]
void
QScxmlNullDataModel::
evaluateForeach
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
,
ForeachLoopBody
*
body
)
重實現自 QScxmlDataModel::evaluateForeach ().
Throws an error and sets
ok
to
false
, because the null data model cannot evaluate
<foreach>
blocks.
[虛擬]
void
QScxmlNullDataModel::
evaluateInitialization
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
)
重實現自 QScxmlDataModel::evaluateInitialization ().
Throws an error and sets
ok
to
false
, because the null data model cannot initialize data.
[虛擬]
bool
QScxmlNullDataModel::
evaluateToBool
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
)
重實現自 QScxmlDataModel::evaluateToBool ().
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.
[虛擬]
QString
QScxmlNullDataModel::
evaluateToString
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
)
重實現自 QScxmlDataModel::evaluateToString ().
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
[虛擬]
QVariant
QScxmlNullDataModel::
evaluateToVariant
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
)
重實現自 QScxmlDataModel::evaluateToVariant ().
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
設為
false
. Returns an empty
QVariant
.
[虛擬]
void
QScxmlNullDataModel::
evaluateToVoid
(
QScxmlExecutableContent::EvaluatorId
id
,
bool
*
ok
)
重實現自 QScxmlDataModel::evaluateToVoid ().
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
設為
false
.
[虛擬]
bool
QScxmlNullDataModel::
hasScxmlProperty
(const
QString
&
name
) const
重實現自 QScxmlDataModel::hasScxmlProperty ().
返迴
false
, because the null data model does not support properties.
[虛擬]
QVariant
QScxmlNullDataModel::
scxmlProperty
(const
QString
&
name
) const
重實現自 QScxmlDataModel::scxmlProperty ().
Returns an invalid variant, because the null data model does not support properties.
另請參閱 setScxmlProperty ().
[虛擬]
void
QScxmlNullDataModel::
setScxmlEvent
(const
QScxmlEvent
&
event
)
重實現自 QScxmlDataModel::setScxmlEvent ().
Does not actually set the event , because the null data model does not handle events.
[虛擬]
bool
QScxmlNullDataModel::
setScxmlProperty
(const
QString
&
name
, const
QVariant
&
value
, const
QString
&
context
)
重實現自 QScxmlDataModel::setScxmlProperty ().
返迴
false
, because the null data model does not support properties.
另請參閱 scxmlProperty ().
[虛擬]
bool
QScxmlNullDataModel::
setup
(const
QVariantMap
&
initialDataValues
)
重實現自 QScxmlDataModel::setup ().