QuickOPC User's Guide and Reference
TryGetFieldValue<TValue>(UAAttributeField,TValue) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA Namespace > UAEventData Class > TryGetFieldValue Method : TryGetFieldValue<TValue>(UAAttributeField,TValue) Method
Type of the value to be retrieved.
Attribute field to look up in the event data.
The value found, or a null reference if the attribute field has not been found or is not of the specified type.
Attempts to retrieve a typed value of specified field from the event data.
Syntax
'Declaration
 
Public Overloads Function TryGetFieldValue(Of TValue)( _
   ByVal attributeField As UAAttributeField, _
   ByRef value As TValue _
) As Boolean
'Usage
 
Dim instance As UAEventData
Dim attributeField As UAAttributeField
Dim value As TValue
Dim value As Boolean
 
value = instance.TryGetFieldValue(Of TValue)(attributeField, value)
public bool TryGetFieldValue<TValue>( 
   UAAttributeField attributeField,
   out TValue value
)
public:
bool TryGetFieldValuegeneric<typename TValue>
( 
   UAAttributeField^ attributeField,
   [Out] TValue^ value
) 

Parameters

attributeField
Attribute field to look up in the event data.
value
The value found, or a null reference if the attribute field has not been found or is not of the specified type.

Type Parameters

TValue
Type of the value to be retrieved.

Return Value

Returns true if the attribute field has been found and is of TValue type; false otherwise.
Exceptions
ExceptionDescription

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also