FindEventCategory Method

Attempts to find a specified event category in the OPC server, and returns information about it when found.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
Public Shared Function FindEventCategory( _
   ByVal client As IEasyAEClient, _
   ByVal serverDescriptor As ServerDescriptor, _
   ByVal categoryId As Long, _
   ByRef categoryElement As AECategoryElement _
) As Boolean

'Usage
 
Dim client As IEasyAEClient
Dim serverDescriptor As ServerDescriptor
Dim categoryId As Long
Dim categoryElement As AECategoryElement
Dim value As Boolean
 
value = IEasyAEClientExtension2.FindEventCategory(client, serverDescriptor, categoryId, categoryElement)

[Extension()]
public static bool FindEventCategory( 
   IEasyAEClient client,
   ServerDescriptor serverDescriptor,
   long categoryId,
   out AECategoryElement categoryElement
)

[Extension()]
public:
static bool FindEventCategory( 
   IEasyAEClient^ client,
   ServerDescriptor^ serverDescriptor,
   int64 categoryId,
   [Out] AECategoryElement^ categoryElement
)

Parameters

client: The client object that will perform the operation.
serverDescriptor: The OPC server involved in the operation.
categoryId: Event category ID to be found.
categoryElement: Information about the event category, if found.

Return Value

Returns 'true' if the event category has been found, 'false' otherwise.

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	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.
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. 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.
OpcLabs.EasyOpc.OperationModel.OpcException	The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause. This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

System.ArgumentNullException

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.

System.ArgumentOutOfRangeException

The value of an argument is outside the allowable range of values as defined by the invoked method.

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.

OpcLabs.EasyOpc.OperationModel.OpcException

The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Requirements

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

Reference

IEasyAEClientExtension2 Class
IEasyAEClientExtension2 Members

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