![](dotnetdiagramimages/OpcLabs_EasyOpcClassicCore_OpcLabs_EasyOpc_AlarmsAndEvents_AddressSpace_AECategoryElementCollection.png)
'Declaration
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.ComTypes._AECategoryElementCollection)> <ComVisibleAttribute(True)> <GuidAttribute("D4383639-C033-4A56-8731-7A18CABDE5BE")> <CLSCompliantAttribute(True)> <TypeConverterAttribute(OpcLabs.BaseLib.Collections.ObjectModel.Implementation.KeyedCollection2TypeConverter)> <DefaultMemberAttribute("Item")> <DebuggerTypeProxyAttribute(System.Collections.Generic.Mscorlib_KeyedCollectionDebugView`2)> <DebuggerDisplayAttribute("Count = {Count}")> <SerializableAttribute()> Public NotInheritable Class AECategoryElementCollection Inherits OpcLabs.BaseLib.Collections.ObjectModel.KeyedCollection2(Of Long,AECategoryElement) Implements OpcLabs.BaseLib.Collections.Generic.IKeyedCollection(Of Long,AECategoryElement), OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.ComTypes._AECategoryElementCollection, System.Collections.Generic.ICollection(Of AECategoryElement), System.Collections.Generic.ICollection(Of T), System.Collections.Generic.IEnumerable(Of AECategoryElement), System.Collections.Generic.IEnumerable(Of T), System.Collections.Generic.IList(Of AECategoryElement), System.Collections.Generic.IReadOnlyCollection(Of AECategoryElement), System.Collections.Generic.IReadOnlyList(Of AECategoryElement), System.Collections.ICollection, System.Collections.IEnumerable, System.Collections.IList, System.ICloneable, System.Xml.Serialization.IXmlSerializable
'Usage
Dim instance As AECategoryElementCollection
[ComDefaultInterface(OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.ComTypes._AECategoryElementCollection)] [ComVisible(true)] [Guid("D4383639-C033-4A56-8731-7A18CABDE5BE")] [CLSCompliant(true)] [TypeConverter(OpcLabs.BaseLib.Collections.ObjectModel.Implementation.KeyedCollection2TypeConverter)] [DefaultMember("Item")] [DebuggerTypeProxy(System.Collections.Generic.Mscorlib_KeyedCollectionDebugView`2)] [DebuggerDisplay("Count = {Count}")] [Serializable()] public sealed class AECategoryElementCollection : OpcLabs.BaseLib.Collections.ObjectModel.KeyedCollection2<long,AECategoryElement>, OpcLabs.BaseLib.Collections.Generic.IKeyedCollection<long,AECategoryElement>, OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.ComTypes._AECategoryElementCollection, System.Collections.Generic.ICollection<AECategoryElement>, System.Collections.Generic.ICollection<T>, System.Collections.Generic.IEnumerable<AECategoryElement>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IList<AECategoryElement>, System.Collections.Generic.IReadOnlyCollection<AECategoryElement>, System.Collections.Generic.IReadOnlyList<AECategoryElement>, System.Collections.ICollection, System.Collections.IEnumerable, System.Collections.IList, System.ICloneable, System.Xml.Serialization.IXmlSerializable
[ComDefaultInterface(OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.ComTypes._AECategoryElementCollection)] [ComVisible(true)] [Guid("D4383639-C033-4A56-8731-7A18CABDE5BE")] [CLSCompliant(true)] [TypeConverter(OpcLabs.BaseLib.Collections.ObjectModel.Implementation.KeyedCollection2TypeConverter)] [DefaultMember("Item")] [DebuggerTypeProxy(System.Collections.Generic.Mscorlib_KeyedCollectionDebugView`2)] [DebuggerDisplay("Count = {Count}")] [Serializable()] public ref class AECategoryElementCollection sealed : public OpcLabs.BaseLib.Collections.ObjectModel.KeyedCollection2<int64,AECategoryElement>, OpcLabs.BaseLib.Collections.Generic.IKeyedCollection<int64,AECategoryElement>, OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.ComTypes._AECategoryElementCollection, System.Collections.Generic.ICollection<AECategoryElement>, System.Collections.Generic.ICollection<T>, System.Collections.Generic.IEnumerable<AECategoryElement>, System.Collections.Generic.IEnumerable<T>, System.Collections.Generic.IList<AECategoryElement>, System.Collections.Generic.IReadOnlyCollection<AECategoryElement>, System.Collections.Generic.IReadOnlyList<AECategoryElement>, System.Collections.ICollection, System.Collections.IEnumerable, System.Collections.IList, System.ICloneable, System.Xml.Serialization.IXmlSerializable
Each OPC Alarms and Events server supports a set of specific event categories. The OPC specifications define a set of recommended categories; however, each OPC server is free to implement some more, vendor-specific event categories as well.
If you want to retrieve a list of all categories available in a given OPC server, call the QueryEventCategories method. You will receive back an AECategoryElementCollection object.
Each AECategoryElement contains information about one OPC event category, such as its (numeric) CategoryId, readable description, and associated event conditions and attributes. The CategoryId can be later used when creating an event filter, and is provided to you in event notifications.
System.Object
System.Collections.ObjectModel.Collection<T>
System.Collections.ObjectModel.KeyedCollection<TKey,TItem>
OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace.AECategoryElementCollection