OPC UA ElementOperand 类型。 更多...
头: | #include <QOpcUaElementOperand> |
CMake: |
find_package(Qt6 REQUIRED COMPONENTS OpcUa)
target_link_libraries(mytarget PRIVATE Qt6::OpcUa) |
qmake: | QT += opcua |
QOpcUaElementOperand () | |
QOpcUaElementOperand (quint32 index ) | |
QOpcUaElementOperand (const QOpcUaElementOperand & rhs ) | |
quint32 | index () const |
void | setIndex (quint32 index ) |
QVariant | operator QVariant () const |
QOpcUaElementOperand & | operator= (const QOpcUaElementOperand & rhs ) |
(从 6.7 起)
bool
|
operator!= (const QOpcUaElementOperand & lhs , const QOpcUaElementOperand & rhs ) |
(从 6.7 起)
bool
|
operator== (const QOpcUaElementOperand & lhs , const QOpcUaElementOperand & rhs ) |
The ElementOperand is defined in OPC UA 1.05 part 4, 7.7.4.2. It is used to identify another element in the filter by its index (the first element has the index 0).
This is required to create complex filters, for example to reference the two operands of the AND operation in ((Severity > 500) AND (Message == "TestString")). The first step is to create content filter elements for the two conditions (Severity > 500) and (Message == "TestString"). A third content filter element is required to create an AND combination of the two conditions. It consists of the AND operator and two element operands with the indices of the two conditions created before:
QOpcUaMonitoringParameters::EventFilter filter; ... // setup select clauses ... QOpcUaContentFilterElement condition1; QOpcUaContentFilterElement condition2; QOpcUaContentFilterElement condition3; condition1 << QOpcUaContentFilterElement::FilterOperator::GreaterThan << QOpcUaSimpleAttributeOperand("Severity") << QOpcUaLiteralOperand(quint16(500), QOpcUa::Types::UInt16); condition2 << QOpcUaContentFilterElement::FilterOperator::Equals << QOpcUaSimpleAttributeOperand("Message") << QOpcUaLiteralOperand("TestString", QOpcUa::Types::String); condition3 << QOpcUaContentFilterElement::FilterOperator::And << QOpcUaElementOperand(0) << QOpcUaElementOperand(1); filter << condition1 << condition2 << condition3;
Default constructs an element operand with no parameters set.
Constructs an element operand with index index .
Constructs an element operand from rhs .
Returns the index of the filter element that is going to be used as operand.
另请参阅 setIndex ().
Sets the index of the filter element that is going to be used as operand to index .
另请参阅 index ().
Converts this element operand to QVariant .
设置值从 rhs in this element operand.
[noexcept, since 6.7]
bool
operator!=
(const
QOpcUaElementOperand
&
lhs
, const
QOpcUaElementOperand
&
rhs
)
返回
true
if
lhs
a different value than
rhs
.
该函数在 Qt 6.7 引入。
[noexcept, since 6.7]
bool
operator==
(const
QOpcUaElementOperand
&
lhs
, const
QOpcUaElementOperand
&
rhs
)
返回
true
if
lhs
has the same value as
rhs
.
该函数在 Qt 6.7 引入。