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



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.LiveMapping.Extensions Namespace > UAMapperExtension Class > ReadTarget Method : ReadTarget(UAClientMapper,Object,String,Boolean) Method
The mapper object that will perform the operation.

The value of this parameter cannot be null (Nothing in Visual Basic).

The object being targeted.

The value of this parameter cannot be null (Nothing in Visual Basic).

The operation will be performed only on mappings tagged with this mapping tag.

The value of this parameter cannot be null (Nothing in Visual Basic).

true to operate on sub-targets (mapped members of the target) recursively; false otherwise.
Executes the "Read" operation on members of given target object, specifying the mapping tag, and recursion flag.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Sub ReadTarget( _
   ByVal mapper As UAClientMapper, _
   ByVal targetObject As Object, _
   ByVal mappingTag As String, _
   ByVal recurse As Boolean _
) 
'Usage
 
Dim mapper As UAClientMapper
Dim targetObject As Object
Dim mappingTag As String
Dim recurse As Boolean
 
UAMapperExtension.ReadTarget(mapper, targetObject, mappingTag, recurse)
[Extension()]
public static void ReadTarget( 
   UAClientMapper mapper,
   object targetObject,
   string mappingTag,
   bool recurse
)

Parameters

mapper
The mapper object that will perform the operation.

The value of this parameter cannot be null (Nothing in Visual Basic).

targetObject
The object being targeted.

The value of this parameter cannot be null (Nothing in Visual Basic).

mappingTag
The operation will be performed only on mappings tagged with this mapping tag.

The value of this parameter cannot be null (Nothing in Visual Basic).

recurse
true to operate on sub-targets (mapped members of the target) recursively; false otherwise.
Exceptions
ExceptionDescription

One of the arguments provided to a method is not valid.

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.

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.

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

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