'Declaration
 
<NotNullAttribute()>
Public Shared ReadOnly Property Null As UAPublisherId

'Usage
 
Dim value As UAPublisherId
 
value = UAPublisherId.Null

[NotNull()]
public static UAPublisherId Null {get;}

[NotNull()]
public:
static property UAPublisherId^ Null {
   UAPublisherId^ get();
}

Property Value

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

Because the UASubscribeDataSetFilter has an implicit conversion from UAPublisherId, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use the returned UAPublisherId (containing the publisher Id that you want to allow in the filter) in any place where UASubscribeDataSetFilter is expected as input, and the corresponding OPC UA subscribe dataset filter will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the UASubscribeDataSetFilter.FromUAPublisherId static method instead.

A null publisher Id cannot appear in the PubSub messages, but it can be used for filtering.

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