OPC Studio User's Guide and Reference
UADataSubscriptionChangedEventArgs Constructor



OpcLabs.ServerOpcUA Assembly > OpcLabs.EasyOpc.UA.OperationModel Namespace > UADataSubscriptionChangedEventArgs Class : UADataSubscriptionChangedEventArgs Constructor
The data variable being processed.

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

The data subscription that is the subject of the change.

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

Describes how the data subscription has changed (add/remove/modify).
Initializes a new instance of the class, specifying individual properties.
Syntax
'Declaration
 
Public Function New( _
   ByVal dataVariable As UADataVariable, _
   ByVal dataSubscription As IUADataSubscription, _
   ByVal action As UADataSubscriptionChangedAction _
)
'Usage
 
Dim dataVariable As UADataVariable
Dim dataSubscription As IUADataSubscription
Dim action As UADataSubscriptionChangedAction
 
Dim instance As New UADataSubscriptionChangedEventArgs(dataVariable, dataSubscription, action)

Parameters

dataVariable
The data variable being processed.

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

dataSubscription
The data subscription that is the subject of the change.

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

action
Describes how the data subscription has changed (add/remove/modify).
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