IsNull Property (UANodeId)

Determines whether the node Id is null.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ColumnDisplayAttribute(MaximumWidth=5, RefinementRank=1)>
<DefaultValueAttribute(True)>
<DisplayAttribute(AutoGenerateField=False, 
   Order=192, 
   ShortName="Is Null")>
<IsValueEvidentAttribute(True)>
Public ReadOnly Property IsNull As Boolean

'Usage
 
Dim instance As UANodeId
Dim value As Boolean
 
value = instance.IsNull

[ColumnDisplay(MaximumWidth=5, RefinementRank=1)]
[DefaultValue(true)]
[Display(AutoGenerateField=false, 
   Order=192, 
   ShortName="Is Null")]
[IsValueEvident(true)]
public bool IsNull {get;}

[ColumnDisplay(MaximumWidth=5, RefinementRank=1)]
[DefaultValue(true)]
[Display(AutoGenerateField=false, 
   Order=192, 
   ShortName="Is Null")]
[IsValueEvident(true)]
public:
property bool IsNull {
   bool get();
}

Remarks

A UANodeId is null when its UANamespaceQualified.NamespaceUriString is empty, and its node Id type is UANodeIdType.None.

Note that the OPC UA node Id, as per OPC specifications, is considered null in a larger number of cases. When UANodeId is constructed from the OPC UA node Id, however, any null node Id is coalesced into Null.

This method or property does not throw any exceptions, aside from execution exceptions such as System.Threading.ThreadAbortException or System.OutOfMemoryException.

Requirements

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

Reference

UANodeId Class
UANodeId Members

Send Documentation Feedback. Resources: Knowledge Base. Technical support: Online Forums, FAQ.