OPC Studio User's Guide and Reference
UnsubscribeMultipleEvents Method



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.AlarmsAndEvents.Extensions Namespace > IEasyAEClientExtension2 Class : UnsubscribeMultipleEvents Method
The client object that will perform the operation.

This is typically the OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient object.

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

Subscription handles. Can be an array.

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

Unsubscribe from changes of multiple OPC events.

Unsubscribe from changes of multiple OPC events, specifying array of integer handles.

Syntax
'Declaration
 
<ExtensionAttribute()>
Public Shared Sub UnsubscribeMultipleEvents( _
   ByVal client As IEasyAEClient, _
   ByVal handles As IEnumerable(Of Integer) _
) 
'Usage
 
Dim client As IEasyAEClient
Dim handles As IEnumerable(Of Integer)
 
IEasyAEClientExtension2.UnsubscribeMultipleEvents(client, handles)
[Extension()]
public static void UnsubscribeMultipleEvents( 
   IEasyAEClient client,
   IEnumerable<int> handles
)
[Extension()]
public:
static void UnsubscribeMultipleEvents( 
   IEasyAEClient^ client,
   IEnumerable<int>^ handles
) 

Parameters

client
The client object that will perform the operation.

This is typically the OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient object.

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

handles
Subscription handles. Can be an array.

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

Exceptions
ExceptionDescription

One of the arguments provided to a method is not valid.

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.

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

The event subscription handles become invalid after this method is called.

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.

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