QueryCategoryAttributes(IEasyAEClient,ServerDescriptor,Int64) Method

Finds out event attributes that the server can provide as part of an event notification within a given event category. Uses server descriptor for specifying the OPC server.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function QueryCategoryAttributes( _
   ByVal client As IEasyAEClient, _
   ByVal serverDescriptor As ServerDescriptor, _
   ByVal categoryId As Long _
) As AEAttributeElementCollection

'Usage
 
Dim client As IEasyAEClient
Dim serverDescriptor As ServerDescriptor
Dim categoryId As Long
Dim value As AEAttributeElementCollection
 
value = IEasyAEClientExtension.QueryCategoryAttributes(client, serverDescriptor, categoryId)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static AEAttributeElementCollection QueryCategoryAttributes( 
   IEasyAEClient client,
   ServerDescriptor serverDescriptor,
   long categoryId
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static AEAttributeElementCollection^ QueryCategoryAttributes( 
   IEasyAEClient^ client,
   ServerDescriptor^ serverDescriptor,
   int64 categoryId
)

Parameters

client: The client object that will perform the operation.
serverDescriptor: The OPC server involved in the operation.
categoryId: An event category Id for which the event attributes should be queried.

Return Value

A collection of attribute elements, one element for each attribute of the given event category.

Exceptions

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.
OpcLabs.EasyOpc.OperationModel.OpcException	The OPC "Classic" (or OPC XML-DA) operation has failed.
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012, Windows Server 2016; .NET Core, .NET 5, .NET 6: Linux, macOS, Microsoft Windows

Reference

IEasyAEClientExtension Class
IEasyAEClientExtension Members
Overload List