'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Shared Function ProcessRead( _
   ByVal dataVariable As UADataVariable, _
   ByVal readFunction As Func(Of UAAttributeData) _
) As UADataVariable

'Usage
 
Dim dataVariable As UADataVariable
Dim readFunction As Func(Of UAAttributeData)
Dim value As UADataVariable
 
value = UADataVariableExtension.ProcessRead(dataVariable, readFunction)

[Extension()]
[NotNull()]
public static UADataVariable ProcessRead( 
   UADataVariable dataVariable,
   Func<UAAttributeData> readFunction
)

[Extension()]
[NotNull()]
public:
static UADataVariable^ ProcessRead( 
   UADataVariable^ dataVariable,
   Func<UAAttributeData^>^ readFunction
) 

Parameters

dataVariable

The data variable that will be modified and returned.

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

readFunction

The read function, i.e. the function that performs the read operation and returns the attribute data that will be returned to the caller of the OPC UA Read.

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

Return Value

This method works by adding an event handler to the Read event of the data variable.

The specified read function is used to process the reads for this data variable only, i.e. not for any of its children. This is achieved by setting the UADataVariable.HandleChildNodes property to false (which you can revert if needed), and also by checking whether the data variable to be processed by the event is this data variable.

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.

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