'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Function SubscribeItem( _
   ByVal client As IEasyDAClient, _
   ByVal itemGroupArguments As DAItemGroupArguments, _
   ByVal callback As EasyDAItemChangedEventHandler _
) As Integer

'Usage
 
Dim client As IEasyDAClient
Dim itemGroupArguments As DAItemGroupArguments
Dim callback As EasyDAItemChangedEventHandler
Dim value As Integer
 
value = IEasyDAClientExtension.SubscribeItem(client, itemGroupArguments, callback)

[Extension()]
public static int SubscribeItem( 
   IEasyDAClient client,
   DAItemGroupArguments itemGroupArguments,
   EasyDAItemChangedEventHandler callback
)

[Extension()]
public:
static int SubscribeItem( 
   IEasyDAClient^ client,
   DAItemGroupArguments^ itemGroupArguments,
   EasyDAItemChangedEventHandler^ callback
) 

Parameters

client

The client object that will perform the operation.

This is typically the EasyDAClient object.

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

itemGroupArguments

Arguments specifying how to subscribe to an OPC DA item.

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

callback

A callback method to be invoked for each significant item change.

The value of this parameter can be null (Nothing in Visual Basic).

Return Value

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