OPC Studio User's Guide and Reference
SubscribeMultipleEvents(IEasyAEClient,AEEventsSubscriptionArguments[],EasyAENotificationEventHandler) Method



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.AlarmsAndEvents.Extensions Namespace > IEasyAEClientExtension2 Class > SubscribeMultipleEvents Method : SubscribeMultipleEvents(IEasyAEClient,AEEventsSubscriptionArguments[],EasyAENotificationEventHandler) 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).

Array of arguments, one element per each OPC events specification involved in the operation.

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

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

A callback method to be invoked for each OPC event.

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

Subscribe to multiple OPC events, specifying an array of event subscription arguments, and a callback.
Syntax
'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function SubscribeMultipleEvents( _
   ByVal client As IEasyAEClient, _
   ByVal eventsSubscriptionArgumentsArray() As AEEventsSubscriptionArguments, _
   ByVal callback As EasyAENotificationEventHandler _
) As Integer()
'Usage
 
Dim client As IEasyAEClient
Dim eventsSubscriptionArgumentsArray() As AEEventsSubscriptionArguments
Dim callback As EasyAENotificationEventHandler
Dim value() As Integer
 
value = IEasyAEClientExtension2.SubscribeMultipleEvents(client, eventsSubscriptionArgumentsArray, callback)

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).

eventsSubscriptionArgumentsArray
Array of arguments, one element per each OPC events specification involved in the operation.

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

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

callback
A callback method to be invoked for each OPC event.

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

Return Value

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 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