QuickOPC User's Guide and Reference
DAItemDescriptor Constructor(DANodeDescriptor,VarType,String)



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.DataAccess Namespace > DAItemDescriptor Class > DAItemDescriptor Constructor : DAItemDescriptor Constructor(DANodeDescriptor,VarType,String)
An node descriptor object to be copied from.
Specifies the data type requested. Passing OpcLabs.BaseLib.ComInterop.VarTypes.Empty means that the server's canonical data type should be used.
An optional data path suggestion to the server.
Initializes a new instance of the DAItemDescriptor class.Initializes a new instance of the class, from specified node descriptor, data type and access path.
Syntax
'Declaration
 
Public Function New( _
   ByVal nodeDescriptor As DANodeDescriptor, _
   ByVal requestedDataType As VarType, _
   ByVal accessPath As String _
)
'Usage
 
Dim nodeDescriptor As DANodeDescriptor
Dim requestedDataType As VarType
Dim accessPath As String
 
Dim instance As New DAItemDescriptor(nodeDescriptor, requestedDataType, accessPath)

Parameters

nodeDescriptor
An node descriptor object to be copied from.
requestedDataType
Specifies the data type requested. Passing OpcLabs.BaseLib.ComInterop.VarTypes.Empty means that the server's canonical data type should be used.
accessPath
An optional data path suggestion to the server.
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.

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