Connectivity Software User's Guide and Reference
ProcessRead Method (SparkplugMetricExtension)



OpcLabs.EasySparkplug Assembly > OpcLabs.EasySparkplug Namespace > SparkplugMetricExtension Class : ProcessRead Method
The Sparkplug metric that will perform the operation.

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

The read function, i.e. the function that performs the read operation and returns the Sparkplug data that will be published.

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

Specifies that reads of this metric will be processed by the specified read function.
Syntax
'Declaration
 
<ExtensionAttribute()>
<JetBrains.Annotations.NotNullAttribute()>
Public Shared Function ProcessRead( _
   ByVal metric As SparkplugMetric, _
   ByVal readFunction As Func(Of SparkplugData) _
) As SparkplugMetric
'Usage
 
Dim metric As SparkplugMetric
Dim readFunction As Func(Of SparkplugData)
Dim value As SparkplugMetric
 
value = SparkplugMetricExtension.ProcessRead(metric, readFunction)
[Extension()]
[JetBrains.Annotations.NotNull()]
public static SparkplugMetric ProcessRead( 
   SparkplugMetric metric,
   Func<SparkplugData> readFunction
)
[Extension()]
[JetBrains.Annotations.NotNull()]
public:
static SparkplugMetric^ ProcessRead( 
   SparkplugMetric^ metric,
   Func<SparkplugData^>^ readFunction
) 

Parameters

metric
The Sparkplug metric that will perform the operation.

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 Sparkplug data that will be published.

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

Return Value

Returns the metric, internally modified as defined by the method.

This method never returns null (Nothing in Visual Basic).

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.

Remarks

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

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.

 

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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