OPC Studio User's Guide and Reference
ReadTarget(UAClientMapper,Object,Predicate<IEnumerable<String>>,Boolean) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.LiveMapping.Extensions Namespace > UAMapperExtension Class > ReadTarget Method : ReadTarget(UAClientMapper,Object,Predicate<IEnumerable<String>>,Boolean) Method
The mapper object that will perform the operation.
The object being targeted.
The operation will be performed only on mappings whose mapping tags satisfy this predicate.
true to operate on sub-targets (mapped members of the target) recursively; false otherwise.
Executes the "Read" operation on members of given target object.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Sub ReadTarget( _
   ByVal mapper As UAClientMapper, _
   ByVal targetObject As Object, _
   ByVal mappingTagsPredicate As Predicate(Of IEnumerable(Of String)), _
   ByVal recurse As Boolean _
) 
'Usage
 
Dim mapper As UAClientMapper
Dim targetObject As Object
Dim mappingTagsPredicate As Predicate(Of IEnumerable(Of String))
Dim recurse As Boolean
 
UAMapperExtension.ReadTarget(mapper, targetObject, mappingTagsPredicate, recurse)

Parameters

mapper
The mapper object that will perform the operation.
targetObject
The object being targeted.
mappingTagsPredicate
The operation will be performed only on mappings whose mapping tags satisfy this predicate.
recurse
true to operate on sub-targets (mapped members of the target) recursively; 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.

The component is not licensed for the operation requested.
Remarks
The "Read" operation reads a value of an OPC-UA attribute and stores it into the mapping source. Only mappings of type OpcLabs.EasyOpc.UA.LiveMapping.UAClientDataMapping that include OpcLabs.EasyOpc.UA.LiveMapping.UADataMappingOperations.Read in their OpcLabs.EasyOpc.UA.LiveMapping.UAClientDataMapping.Operations are affected; other mappings are ignored.
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