# OpcNode Members > Reference: Represents the base class of the node classes which define the nodes of an address space, such as OpcObjectNode, OpcVariableNode and OpcMethodNode.
Type
OpcNode
Namespace
Opc.UaFx
Assembly
Opc.UaFx.Advanced.dll
Package
Opc.UaFx.Advanced v2.59.0
## Properties ### Category Gets the [NodeCategory](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#nodecategory) attribute which identifies the kind of node and is therefore used to classify the node regarding its use and purpose.
```csharp public OpcNodeCategory Category { get; } ```
```vbnet Public ReadOnly Property Category As OpcNodeCategory ```
**Property value** [OpcNodeCategory](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodecategory/) One of the members defined by the [OpcNodeCategory](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodecategory/) enumeration. **Implements** [Category](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#category) ### Description Gets or sets the value of the optional [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#description) attribute which shall explain the meaning of the node.
```csharp public OpcText Description { get; set; } ```
```vbnet Public Property Description As OpcText ```
**Property value** [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/) A localizable instance of the [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/) class which optionally explains the meaning of the node or a null reference (Nothing in Visual Basic) if there is no description associated with the node. **Implements** [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#description), [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#description) **Remarks** The menaning of the node defines the usage, the context and the purpose of the node. ### Descriptions since v2.12 Gets the [OpcNodeGlobalization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeglobalization/) instance used to control the localization and other globalization related tasks for the [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#description) attribute of the current node.
```csharp public OpcNodeGlobalization Descriptions { get; } ```
```vbnet Public ReadOnly Property Descriptions As OpcNodeGlobalization ```
**Property value** [OpcNodeGlobalization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeglobalization/) An instance of the [OpcNodeGlobalization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeglobalization/) class used by the current [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) to perform localization tasks for its [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#description). ### DisplayName Gets or sets the value of the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#displayname) attribute which defines the localizable name of the node.
```csharp public OpcText DisplayName { get; set; } ```
```vbnet Public Property DisplayName As OpcText ```
**Property value** [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/) An instance of the [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/) class which defines the localizable name of the node. **Implements** [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#displayname), [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#displayname) **Remarks** Client application should use this attribute if they want to display the name of the node to the user. The [string](https://learn.microsoft.com/dotnet/api/system.string) part of the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#displayname) is restricted to 512 characters. ### DisplayNames since v2.12 Gets the [OpcNodeGlobalization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeglobalization/) instance used to control the localization and other globalization related tasks for the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#displayname) attribute of the current node.
```csharp public OpcNodeGlobalization DisplayNames { get; } ```
```vbnet Public ReadOnly Property DisplayNames As OpcNodeGlobalization ```
**Property value** [OpcNodeGlobalization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeglobalization/) An instance of the [OpcNodeGlobalization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeglobalization/) class used by the current [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) to perform localization tasks for its [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#displayname). ### HasPendingChanges Gets a value indiciating whether there exists any pending change on the node.
```csharp public bool HasPendingChanges { get; } ```
```vbnet Public ReadOnly Property HasPendingChanges As Boolean ```
**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) is not equals to [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none); otherwise the value false. **Implements** [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#haspendingchanges) ### Id Gets the value of the [NodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#nodeid) attribute which unambiguously identifies the node.
```csharp public OpcNodeId Id { get; } ```
```vbnet Public ReadOnly Property Id As OpcNodeId ```
**Property value** [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) An instance of the [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) class representing the unambiguously identifier of the node. **Implements** [Id](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#id) **Remarks** Some servers may accept alternative node identifiers in addition to the canonical node identifier represented by this attribute. A server shall persist the node identifier of a node, that is, it shall not generate new node identifiers when rebooting. ### Model since v2.50 Gets the [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) which has been used to model this [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) regarding its whole representation in the address space.
```csharp public OpcNodeModel Model { get; } ```
```vbnet Public ReadOnly Property Model As OpcNodeModel ```
**Property value** [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) An instance of the [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) class which provides the modelling directives to use to model the whole node tree of this [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/). ### Name Gets or sets the value of the [BrowseName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#browsename) attribute which defines the non-localizable human-readable name used when browsing the address space.
```csharp public OpcName Name { get; set; } ```
```vbnet Public Property Name As OpcName ```
**Property value** [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) **Implements** [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#name), [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#name) **Remarks** The [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) should never be used to display the name of the a node. Use the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#displayname) instead for this purpose. Unlike node identifiers the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) cannot be used to unambiguously identify the node. Different nodes may have the same browse name. The namespace is provided to make the browse name unique in some cases in the context of a node (e.g. properties of a node) although not unique in the context of the server. If different organizations define browse names for properties, the namespace of the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) provided by the organization makes the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) unique, although different organizations may use the same string having a slightly different meaning. Servers may often choose to use the same namespace for the node identifier and the browse name. However, if they want to provide a standard property, its browse name shall have the namespace of the standards body although the namespace of the node identifier reflects something else, for example the local server. It is recommended that standard bodies defining standard type definitions use their namespace for the node identifier of the type definition node as well as for the browse name of the type definition node. The [string](https://learn.microsoft.com/dotnet/api/system.string)-part of the browse name is case sensitive. That is, clients shall consider them case sensitive. Server are allowed to handle browse names passed in service requests as case insensitive. Use the value of this property to construct browse paths (see [OpcNamePath](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamepath/)). ### Namespace Gets the namespace of the node.
```csharp public OpcNamespace Namespace { get; } ```
```vbnet Public ReadOnly Property [Namespace] As OpcNamespace ```
**Property value** [OpcNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamespace/) The [OpcNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamespace/) assigned to the node or, if no namespace has been assigned to the node, the [Namespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/members#namespace) of its [Id](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#id). **Implements** [Namespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#namespace) ### Parent virtual Gets the parent node of the node.
```csharp public virtual IOpcNode Parent { get; } ```
```vbnet Public Overridable ReadOnly Property Parent As IOpcNode ```
**Property value** [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) An instance implementing the [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) interface which represents the phyiscal parent of the node. In general a node can have multiple (logical) parent nodes, but this property provides the only physical parent node of the node. The value can also be a null reference (Nothing in Visual Basic) in case there the node does only have logical parent nodes. **Implements** [Parent](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#parent) ### PendingChanges Gets a value indicating the most recent changes performed on the node since their last notification.
```csharp public OpcNodeChanges PendingChanges { get; } ```
```vbnet Public ReadOnly Property PendingChanges As OpcNodeChanges ```
**Property value** [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) A bitwise combination of [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) members identifying the changes made on the node or [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none) if there was no change on the node since the last change notification. **Implements** [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#pendingchanges) **Remarks** Use one of the [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext) overloads to reset the value of this property to [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none) or use one of the [UpdateChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#updatechanges-opc-uafx-opccontext-opc-uafx-opcnodechanges) overloads to partially reset the pending changes. ### QueryEventsCallback Gets or sets a callback used to query any event information which belongs to the node.
```csharp public OpcQueryEventsCallback QueryEventsCallback { get; set; } ```
```vbnet Public Property QueryEventsCallback As OpcQueryEventsCallback ```
**Property value** [OpcQueryEventsCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcqueryeventscallback/) A [OpcQueryEventsCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcqueryeventscallback/) used to query any event information which belongs to the node. The value can also be a null reference (Nothing in Visual Basic). **Remarks** A condition refresh reports the retained conditions of the node's children and of the nodes added by [AddNotifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#addnotifier) without the callback. Reporting such a condition from the callback as well makes a client receive it twice. The callback is meant for event information that is no child and no notifier of the node. ### ReadDescriptionCallback Gets or sets a callback used to read the value of the [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#description) attribute.
```csharp public OpcReadAttributeValueCallback ReadDescriptionCallback { get; set; } ```
```vbnet Public Property ReadDescriptionCallback As OpcReadAttributeValueCallback(Of OpcText) ```
**Property value** [OpcReadAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/)<[OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/)> A [OpcReadAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/) used to read the value of the [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#description) attribute as an [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/). The value can also be a null reference (Nothing in Visual Basic). ### ReadDisplayNameCallback since v2.11 Gets or sets a callback used to read the value of the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#displayname) attribute.
```csharp public OpcReadAttributeValueCallback ReadDisplayNameCallback { get; set; } ```
```vbnet Public Property ReadDisplayNameCallback As OpcReadAttributeValueCallback(Of OpcText) ```
**Property value** [OpcReadAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/)<[OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/)> A [OpcReadAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/) used to read the value of the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#displayname) attribute as an [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/). The value can also be a null reference (Nothing in Visual Basic). ### ReadUserWriteAccessCallback Gets or sets a callback used to read the value of the [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#userwriteaccess) attribute.
```csharp public OpcReadAttributeValueCallback ReadUserWriteAccessCallback { get; set; } ```
```vbnet Public Property ReadUserWriteAccessCallback As OpcReadAttributeValueCallback(Of OpcAttributeWriteAccess) ```
**Property value** [OpcReadAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/)<[OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/)> A [OpcReadAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/) used to read the value of the [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#userwriteaccess) attribute as a combination of the members defined by the [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) enumeration. The value can also be a null reference (Nothing in Visual Basic). ### ReadWriteAccessCallback Gets or sets a callback used to read the value of the [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#writeaccess) attribute.
```csharp public OpcReadAttributeValueCallback ReadWriteAccessCallback { get; set; } ```
```vbnet Public Property ReadWriteAccessCallback As OpcReadAttributeValueCallback(Of OpcAttributeWriteAccess) ```
**Property value** [OpcReadAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/)<[OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/)> A [OpcReadAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecallback-1/) used to read the value of the [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#writeaccess) attribute as a combination of the members defined by the [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) enumeration. The value can also be a null reference (Nothing in Visual Basic). ### SymbolicName Gets or sets a symbolic name for the node which is not expected to be globally unique.
```csharp public string SymbolicName { get; set; } ```
```vbnet Public Property SymbolicName As String ```
**Property value** [String](https://learn.microsoft.com/dotnet/api/system.string) The symbolic name of the node or a null reference (Nothing in Visual Basic) if there is no symbolic name assigned. The name can only contain characters which are valid for an XML element name. **Implements** [SymbolicName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#symbolicname) **Remarks** The symbolic name is not an attribute of the node and is therefore not provided to clients; it is used when the state of the node is saved, for example as the name of its XML element. In case there [UseNodeNameAsDefaultSymbolicName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcautomatism/members#usenodenameasdefaultsymbolicname) is set to the value true and no symbolic name is assigned, the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/members#value) of the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) is used as the symbolic name when the node is initialized. ### Tag Gets or sets the object that contains additional user data about the node.
```csharp public object Tag { get; set; } ```
```vbnet Public Property Tag As Object ```
**Property value** [Object](https://learn.microsoft.com/dotnet/api/system.object) An [object](https://learn.microsoft.com/dotnet/api/system.object) that contains additional user data about the node. The default is null (Nothing in Visual Basic). **Implements** [Tag](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#tag) ### UserWriteAccess Gets or sets the value of the optional [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#userwriteaccess) attribute which exposes the possibilities of a client to write the attributes of the node taking user access rights into account.
```csharp public OpcAttributeWriteAccess UserWriteAccess { get; set; } ```
```vbnet Public Property UserWriteAccess As OpcAttributeWriteAccess ```
**Property value** [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) A combination of the members defined by the [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) enumeration. **Implements** [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#userwriteaccess), [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#userwriteaccess) **Remarks** The mask value of this attribute can only further restrict the [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#writeaccess) attribute, when it is set to not writable in the general case that applies for every user. ### WriteAccess Gets or sets the value of the optional [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#writeaccess) attribute which exposes the posibilities of a client to write the attributes of the node.
```csharp public OpcAttributeWriteAccess WriteAccess { get; set; } ```
```vbnet Public Property WriteAccess As OpcAttributeWriteAccess ```
**Property value** [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) A combination of the members defined by the [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) enumeration. **Implements** [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#writeaccess), [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#writeaccess) **Remarks** The mask value of this attribute does not take any user access rights into account, that is, altough an attribute is writable this may be restricted to a certain user / user group. If a server does not have the ability to get the write mask information for a specific attribute from the underlying system, it should state that it is writable. If a write opertation is called on the attribute, the server should transfer this request and return the corresponding [OpcStatusCode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatuscode/) if such a request is rejected. Only in case there a corresponding attribute is set in the mask of this attribute the according attribute is writable; otherwise it can not accessed for writing. ### WriteDescriptionCallback Gets or sets a callback used to write the value of the [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#description) attribute.
```csharp public OpcWriteAttributeValueCallback WriteDescriptionCallback { get; set; } ```
```vbnet Public Property WriteDescriptionCallback As OpcWriteAttributeValueCallback(Of OpcText) ```
**Property value** [OpcWriteAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/)<[OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/)> A [OpcWriteAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/) used to write the value of the [Description](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#description) attribute as an [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/). The value can also be a null reference (Nothing in Visual Basic). ### WriteDisplayNameCallback since v2.11 Gets or sets a callback used to write the value of the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#displayname) attribute.
```csharp public OpcWriteAttributeValueCallback WriteDisplayNameCallback { get; set; } ```
```vbnet Public Property WriteDisplayNameCallback As OpcWriteAttributeValueCallback(Of OpcText) ```
**Property value** [OpcWriteAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/)<[OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/)> A [OpcWriteAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/) used to write the value of the [DisplayName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#displayname) attribute as an [OpcText](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctext/). The value can also be a null reference (Nothing in Visual Basic). ### WriteUserWriteAccessCallback Gets or sets a callback used to write the value of the [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#userwriteaccess) attribute.
```csharp public OpcWriteAttributeValueCallback WriteUserWriteAccessCallback { get; set; } ```
```vbnet Public Property WriteUserWriteAccessCallback As OpcWriteAttributeValueCallback(Of OpcAttributeWriteAccess) ```
**Property value** [OpcWriteAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/)<[OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/)> A [OpcWriteAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/) used to write the value of the [UserWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#userwriteaccess) attribute as a combination of the members defined by the [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) enumeration. The value can also be a null reference (Nothing in Visual Basic). ### WriteWriteAccessCallback Gets or sets a callback used to write the value of the [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#writeaccess) attribute.
```csharp public OpcWriteAttributeValueCallback WriteWriteAccessCallback { get; set; } ```
```vbnet Public Property WriteWriteAccessCallback As OpcWriteAttributeValueCallback(Of OpcAttributeWriteAccess) ```
**Property value** [OpcWriteAttributeValueCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/)<[OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/)> A [OpcWriteAttributeValueCallback<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecallback-1/) used to write the value of the [WriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#writeaccess) attribute as a combination of the members defined by the [OpcAttributeWriteAccess](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributewriteaccess/) enumeration. The value can also be a null reference (Nothing in Visual Basic). ## Methods ### AddNotifier virtual When implemented in a subtype, adds the `node` to the collection of notifiers (= event sources) of this node.
```csharp public virtual void AddNotifier(OpcContext context, IOpcNode node) ```
```vbnet Public Overridable Sub AddNotifier(context As OpcContext, node As IOpcNode) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to add the `node` as the notifying event source. | | `node` | [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) | The [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) instance acting as the notifier. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` or `node` is null reference (Nothing in Visual Basic). | | [NotSupportedException](https://learn.microsoft.com/dotnet/api/system.notsupportedexception) | Adding notifiers is only supported on [OpcObjectNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/) and its subclasses. | **Implements** [AddNotifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#addnotifier) **Remarks** If the `node` is the first notifier being added to the collection of notifiers the [EventNotifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#eventnotifier) attribute of this [OpcObjectNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/) is set to 'SubscribeToEvents'. ### ApplyChanges virtual · 2 overloads | Overload | Description | |---|---| | [ApplyChanges(OpcContext)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext)virtual | Notifies about changes performed on the node since the last notification and resets the pending changes to [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none). | | [ApplyChanges(OpcContext, bool)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext-system-boolean)virtual | Notifies about changes performed on the node (and optionally on its children) since the last notification and resets the pending changes to [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none). | **Exceptions (all overloads)** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` is a null reference (Nothing in Visual Basic). | #### ApplyChanges(OpcContext) virtual Notifies about changes performed on the node since the last notification and resets the pending changes to [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none).
```csharp public virtual void ApplyChanges(OpcContext context) ```
```vbnet Public Overridable Sub ApplyChanges(context As OpcContext) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to notify about changes performed on the node. | **Implements** [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#applychanges-opc-uafx-opccontext) **Remarks** This method influences the value of the properties [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) and [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#haspendingchanges). After a call to [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext) the [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) property returns [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none) and the [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#haspendingchanges) the value false. The method is not synchronized, see [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext-system-boolean). #### ApplyChanges(OpcContext, bool) virtual Notifies about changes performed on the node (and optionally on its children) since the last notification and resets the pending changes to [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none).
```csharp public virtual void ApplyChanges(OpcContext context, bool recursive) ```
```vbnet Public Overridable Sub ApplyChanges(context As OpcContext, recursive As Boolean) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to notify about changes performed on the node. | | `recursive` | [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) | The value true if pending changes are to be notified for all children as well; otherwise the value false. | **Implements** [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#applychanges-opc-uafx-opccontext-system-boolean) **Remarks** This method influences the value of the properties [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) and [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#haspendingchanges). After a call to [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext-system-boolean) the [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) property returns [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/#none) and the [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#haspendingchanges) the value false. The method is not synchronized. A change made by another thread while the method runs can be reset without being notified. Change and apply the changes of a node from one thread at a time, or hold `OpcNodeManager.SyncRoot` of the node manager of the node, which describes what that lock covers. ### AttributeValue 2 overloads · since v2.9 | Overload | Description | |---|---| | [AttributeValue(OpcAttribute)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#attributevalue-opc-uafx-opcattribute)since v2.9 | Retrieves the value of the `attribute` specified. | | [AttributeValue<T>(OpcAttribute)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#attributevalue-t1-opc-uafx-opcattribute)since v2.9 | Retrieves the value of the `attribute` specified. | #### AttributeValue(OpcAttribute) since v2.9 Retrieves the value of the `attribute` specified.
```csharp public object AttributeValue(OpcAttribute attribute) ```
```vbnet Public Function AttributeValue(attribute As OpcAttribute) As Object ```
**Parameters** | Name | Type | Description | |---|---|---| | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration which identifies the attribute its value is queried. | **Returns** [Object](https://learn.microsoft.com/dotnet/api/system.object) The value of the `attribute` specified or a null reference (Nothing in Visual Basic) in case there the value of the attribute is a null reference or it is not supported by the current [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/). **Implements** [AttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#attributevalue-opc-uafx-opcattribute) #### AttributeValue<T>(OpcAttribute) since v2.9 Retrieves the value of the `attribute` specified.
```csharp public T AttributeValue(OpcAttribute attribute) ```
```vbnet Public Function AttributeValue(Of T)(attribute As OpcAttribute) As T ```
**Type parameters** | Name | Description | |---|---| | `T` | The expected type of value the attribute shall offer. | **Parameters** | Name | Type | Description | |---|---|---| | `attribute` | [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) | One of the members defined by the [OpcAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/) enumeration which identifies the attribute its value is queried. | **Returns** T The value of the `attribute` as the type `T` specified or the default value of the type `T` in case there the value of the attribute is a null reference (Nothing in Visual Basic) or it is not supported by the current [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/). **Implements** [AttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#attributevalue-t1-opc-uafx-opcattribute) ### Child since v2.7 Retrieves the child node its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) property matches exactly the `name` specified.
```csharp public IOpcNode Child(OpcContext context, OpcName name) ```
```vbnet Public Function Child(context As OpcContext, name As OpcName) As IOpcNode ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to lookup the requested child node. | | `name` | [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) | The full qualified [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) of the node to lookup. | **Returns** [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) An instance implementing the [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) interface its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) exactly matches the `name` specified, if such a node is a known child node of this node. Otherwise a null reference (Nothing in Visual Basic). **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` or `name` is a null reference (Nothing in Visual Basic). | **Implements** [Child](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#child) ### ChildModel protected · since v2.50 Retrieves the model of the child node with the `name` specified from the [Model](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#model) of the node.
```csharp protected OpcNodeModel ChildModel(OpcName name) ```
```vbnet Protected Function ChildModel(name As OpcName) As OpcNodeModel ```
**Parameters** | Name | Type | Description | |---|---|---| | `name` | [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) | The [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) of the child node whose model is to be retrieved. | **Returns** [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) The [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) defined for the child node with the `name` specified, the model defined for all children if there is no model for the specific child node or [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/members#none) if neither of them is defined. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `name` is a null reference (Nothing in Visual Basic). | ### ChildModellingDirective protected · since v2.50 Retrieves the modelling directive of the child node with the `name` specified from the [Model](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#model) of the node.
```csharp protected OpcModellingDirective ChildModellingDirective(OpcName name) ```
```vbnet Protected Function ChildModellingDirective( name As OpcName) As OpcModellingDirective ```
**Parameters** | Name | Type | Description | |---|---|---| | `name` | [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) | The [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) of the child node whose modelling directive is to be retrieved. | **Returns** [OpcModellingDirective](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodellingdirective/) The [Directive](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/members#directive) of the model which [ChildModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#childmodel) retrieves for the child node. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `name` is a null reference (Nothing in Visual Basic). | ### Children Retrieves a sequence of all nodes organized as children of this node.
```csharp public IEnumerable Children(OpcContext context) ```
```vbnet Public Function Children(context As OpcContext) As IEnumerable(Of IOpcNode) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to lookup the child nodes. | **Returns** [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)<[IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/)> A sequence of instances implementing the [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) interface which representing the nodes organized as child nodes of this node. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` is a null reference (Nothing in Visual Basic). | **Implements** [Children](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#children) ### DefineModel protected · static · 2 overloads · since v2.27 | Overload | Description | |---|---| | [DefineModel<T>(OpcModellingRule, OpcNamePath)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#definemodel-t1-opc-uafx-opcmodellingrule-opc-uafx-opcnamepath)protected · static · since v2.27 | Defines a model rule for the model of the node type specified by `T` using the `rule` which is to be applied to the node known under the `path` passed. | | [DefineModel<T>(OpcModellingRule, params OpcName\[\])](#definemodel-t1-opc-uafx-opcmodellingrule-opc-uafx-opcname-array)protected · static · since v2.27 | Defines a model rule for the model of the node type specified by `T` using the `rule` which is to be applied to the node known under the `pathElements` passed. | #### DefineModel<T>(OpcModellingRule, OpcNamePath) protected · static · since v2.27 Defines a model rule for the model of the node type specified by `T` using the `rule` which is to be applied to the node known under the `path` passed.
```csharp protected static void DefineModel( OpcModellingRule rule, OpcNamePath path) where T : OpcNode ```
```vbnet Protected Shared Sub DefineModel(Of T As OpcNode)( rule As OpcModellingRule, path As OpcNamePath) ```
**Type parameters** | Name | Description | |---|---| | `T` | The type of [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) for which the model rule is to be applied. | **Parameters** | Name | Type | Description | |---|---|---| | `rule` | [OpcModellingRule](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodellingrule/) | The [OpcModellingRule](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodellingrule/) to apply. | | `path` | [OpcNamePath](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamepath/) | The [OpcNamePath](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamepath/) to the node affected. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `path` is a null reference (Nothing in Visual Basic). | #### DefineModel<T>(OpcModellingRule, params OpcName\[\]) protected · static · since v2.27 Defines a model rule for the model of the node type specified by `T` using the `rule` which is to be applied to the node known under the `pathElements` passed.
```csharp protected static void DefineModel( OpcModellingRule rule, params OpcName[] pathElements) where T : OpcNode ```
```vbnet Protected Shared Sub DefineModel(Of T As OpcNode)( rule As OpcModellingRule, ParamArray pathElements As OpcName()) ```
**Type parameters** | Name | Description | |---|---| | `T` | The type of [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) for which the model rule is to be applied. | **Parameters** | Name | Type | Description | |---|---|---| | `rule` | [OpcModellingRule](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodellingrule/) | The [OpcModellingRule](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcmodellingrule/) to apply. | | `pathElements` | params [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/)[] | The [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/)'s to the node affected. | ### GetType static · since v2.20 Retrieves the [Type](https://learn.microsoft.com/dotnet/api/system.type) which implementes the node type which is identified by the `typeId` specified.
```csharp public static Type GetType(OpcNodeId typeId) ```
```vbnet Public Shared Function [GetType](typeId As OpcNodeId) As Type ```
**Parameters** | Name | Type | Description | |---|---|---| | `typeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) which identifies the [Type](https://learn.microsoft.com/dotnet/api/system.type) to retrieve. | **Returns** [Type](https://learn.microsoft.com/dotnet/api/system.type) The [Type](https://learn.microsoft.com/dotnet/api/system.type) which is known under the `typeId` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [Type](https://learn.microsoft.com/dotnet/api/system.type) which is associated with the `typeId` specified. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `typeId` is a null reference (Nothing in Visual Basic). | ### GetTypeInfo static · 3 overloads · since v2.20 | Overload | Description | |---|---| | [GetTypeInfo<T>()](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#gettypeinfo-t1)static · since v2.20 | Retrieves the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the node type implemented by the `T` specified. | | [GetTypeInfo(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#gettypeinfo-opc-uafx-opcnodeid)static · since v2.20 | Retrieves the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the node type which is identified by the `typeId` specified. | | [GetTypeInfo(Type)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#gettypeinfo-system-type)static · since v2.20 | Retrieves the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the node type implemented by the `underlyingType` specified. | #### GetTypeInfo<T>() static · since v2.20 Retrieves the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the node type implemented by the `T` specified.
```csharp public static OpcNodeTypeInfo GetTypeInfo() ```
```vbnet Public Shared Function GetTypeInfo(Of T)() As OpcNodeTypeInfo ```
**Type parameters** | Name | Description | |---|---| | `T` | The [Type](https://learn.microsoft.com/dotnet/api/system.type) which implements the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) to retrieve. | **Returns** [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) The [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the `T` specified or a null reference (Nothing in Visual Basic) if there isn't a [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) associated with the `T` specified. #### GetTypeInfo(OpcNodeId) static · since v2.20 Retrieves the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the node type which is identified by the `typeId` specified.
```csharp public static OpcNodeTypeInfo GetTypeInfo(OpcNodeId typeId) ```
```vbnet Public Shared Function GetTypeInfo(typeId As OpcNodeId) As OpcNodeTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `typeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) which identifies the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) to retrieve. | **Returns** [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) The [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which is known under the `typeId` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which is associated with the `typeId` specified. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `typeId` is a null reference (Nothing in Visual Basic). | #### GetTypeInfo(Type) static · since v2.20 Retrieves the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the node type implemented by the `underlyingType` specified.
```csharp public static OpcNodeTypeInfo GetTypeInfo(Type underlyingType) ```
```vbnet Public Shared Function GetTypeInfo(underlyingType As Type) As OpcNodeTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `underlyingType` | [Type](https://learn.microsoft.com/dotnet/api/system.type) | The [Type](https://learn.microsoft.com/dotnet/api/system.type) which implements the [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) to retrieve. | **Returns** [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) The [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) which declares the `underlyingType` specified or a null reference (Nothing in Visual Basic) if there isn't a [OpcNodeTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeinfo/) associated with the `underlyingType` specified. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `underlyingType` is a null reference (Nothing in Visual Basic). | ### Implement protected · virtual · since v2.26 Performs node specific implementation tasks to finalize the node creation before it can be used for the first time.
```csharp protected virtual void Implement(OpcContext context) ```
```vbnet Protected Overridable Sub Implement(context As OpcContext) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to implement the node. | ### InitializeChildren protected · virtual · since v2.54 Initializes the children of the node.
```csharp protected virtual void InitializeChildren(OpcContext context) ```
```vbnet Protected Overridable Sub InitializeChildren(context As OpcContext) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to initialize the children. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` is a null reference (Nothing in Visual Basic). | ### InitializeDefaults protected · virtual Initializes the default values used by the node implementation represented / required.
```csharp protected virtual void InitializeDefaults() ```
```vbnet Protected Overridable Sub InitializeDefaults() ```
**Remarks** This method is always called by the lowest constructor of the [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) constructor chain to initialize all default values which are explicitly necessary before the node is (for example) added as a child node of another node. In case there a parent node is passed to constructor this becomes essential to ensure that the node is initialized appropriately before it is added to the parent. Only implement this method in case there is a custom node setup required (typically performed within the custom constructor). Any code for member field initialization or additional logic can be kept in the constructor. ### IsAccessible virtual · since v2.54 Determines whether the node is accessible using the `context` specified within the view identified by the `viewId` specified.
```csharp public virtual bool IsAccessible(OpcContext context, OpcNodeId viewId) ```
```vbnet Public Overridable Function IsAccessible( context As OpcContext, viewId As OpcNodeId) As Boolean ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) within that the node is accessed. | | `viewId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) of the view within that the node is accessed or [Null](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/members#null) if the node is not accessed within a specific view. | **Returns** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the node is accessible; otherwise the value false. The default implementation always returns the value true. ### IsChangePending Determines whether all of the changes specified by the `change` are pending on the node (see [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges)).
```csharp public bool IsChangePending(OpcNodeChanges change) ```
```vbnet Public Function IsChangePending(change As OpcNodeChanges) As Boolean ```
**Parameters** | Name | Type | Description | |---|---|---| | `change` | [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) | A bitwise combination of [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) members identifying the changes to check. | **Returns** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if all of the changes specified by the `change` are pending on the node; otherwise the value false. **Implements** [IsChangePending](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#ischangepending) ### OnAfterAdded protected · virtual · since v2.26 Raises the [AfterAdded](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#afteradded) event using the event data specified.
```csharp protected virtual void OnAfterAdded(OpcNodeAddedEventArgs e) ```
```vbnet Protected Overridable Sub OnAfterAdded(e As OpcNodeAddedEventArgs) ```
**Parameters** | Name | Type | Description | |---|---|---| | `e` | [OpcNodeAddedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeaddedeventargs/) | The [OpcNodeAddedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeaddedeventargs/) with the event data. | ### OnAfterApplyChanges protected · virtual · since v2.10 Raises the [AfterApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#afterapplychanges) event using the event data specified.
```csharp protected virtual void OnAfterApplyChanges(OpcNodeChangesEventArgs e) ```
```vbnet Protected Overridable Sub OnAfterApplyChanges(e As OpcNodeChangesEventArgs) ```
**Parameters** | Name | Type | Description | |---|---|---| | `e` | [OpcNodeChangesEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventargs/) | The [OpcNodeChangesEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventargs/) with the event data. | ### OnBeforeAdded protected · virtual · since v2.26 Raises the [BeforeAdded](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#beforeadded) event using the event data specified.
```csharp protected virtual void OnBeforeAdded(OpcNodeAddedEventArgs e) ```
```vbnet Protected Overridable Sub OnBeforeAdded(e As OpcNodeAddedEventArgs) ```
**Parameters** | Name | Type | Description | |---|---|---| | `e` | [OpcNodeAddedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeaddedeventargs/) | The [OpcNodeAddedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeaddedeventargs/) with the event data. | ### OnBeforeApplyChanges protected · virtual · since v2.10 Raises the [BeforeApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#beforeapplychanges) event using the event data specified.
```csharp protected virtual void OnBeforeApplyChanges(OpcNodeChangesEventArgs e) ```
```vbnet Protected Overridable Sub OnBeforeApplyChanges(e As OpcNodeChangesEventArgs) ```
**Parameters** | Name | Type | Description | |---|---|---| | `e` | [OpcNodeChangesEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventargs/) | The [OpcNodeChangesEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventargs/) with the event data. | ### OnChangesUnhandled protected · virtual · since v2.50 Raises the [ChangesUnhandled](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#changesunhandled) event using the event data specified.
```csharp protected virtual void OnChangesUnhandled(OpcNodeChangesEventArgs e) ```
```vbnet Protected Overridable Sub OnChangesUnhandled(e As OpcNodeChangesEventArgs) ```
**Parameters** | Name | Type | Description | |---|---|---| | `e` | [OpcNodeChangesEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventargs/) | The [OpcNodeChangesEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventargs/) with the event data. | ### OnEventReported protected · virtual · since v2.54 Raises the [EventReported](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#eventreported) event using the event data specified.
```csharp protected virtual void OnEventReported(OpcNodeEventReportedEventArgs e) ```
```vbnet Protected Overridable Sub OnEventReported(e As OpcNodeEventReportedEventArgs) ```
**Parameters** | Name | Type | Description | |---|---|---| | `e` | [OpcNodeEventReportedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeeventreportedeventargs/) | The [OpcNodeEventReportedEventArgs](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeeventreportedeventargs/) with the event data. | ### QueryEventsCore protected · virtual Queries the events which belong to the node using the [QueryEventsCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#queryeventscallback), if one is assigned.
```csharp protected virtual void QueryEventsCore( OpcNodeContext context, OpcEventCollection events) ```
```vbnet Protected Overridable Sub QueryEventsCore( context As OpcNodeContext, events As OpcEventCollection) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcNodeContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodecontext/) | The [OpcNodeContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodecontext/) to use to query the node events. | | `events` | [OpcEventCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventcollection/) | The [OpcEventCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventcollection/) to use to store the result of the query. | ### ReadAttributeValueCore protected · virtual Determines the value of the attribute to read. In case there a callback is assigned to read the value of the attribute (see [ReadDisplayNameCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#readdisplaynamecallback), [ReadDescriptionCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#readdescriptioncallback), [ReadUserWriteAccessCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#readuserwriteaccesscallback) and [ReadWriteAccessCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#readwriteaccesscallback)) the callback determines the value; otherwise the preliminary `value` is returned.
```csharp protected virtual OpcAttributeValue ReadAttributeValueCore( OpcReadAttributeValueContext context, OpcAttributeValue value) ```
```vbnet Protected Overridable Function ReadAttributeValueCore(Of T)( context As OpcReadAttributeValueContext, value As OpcAttributeValue(Of T)) As OpcAttributeValue(Of T) ```
**Type parameters** | Name | Description | |---|---| | `T` | The type of attribute value to read. | **Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcReadAttributeValueContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecontext/) | The [OpcReadAttributeValueContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreadattributevaluecontext/) to use to read the attribute value. | | `value` | [OpcAttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/)<T> | The preliminary [OpcAttributeValue<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/). | **Returns** [OpcAttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/)<T> The determined [OpcAttributeValue<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/). ### References virtual · since v2.50 Retrieves a sequence of immutable references between this node and other nodes.
```csharp public virtual IEnumerable References() ```
```vbnet Public Overridable Function References() As IEnumerable(Of OpcReference) ```
**Returns** [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)<[OpcReference](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreference/)> A sequence of [OpcReference](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcreference/) instances providing hierarchical and non-hierarchical references from this node to other nodes. **Implements** [References](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnodeinfo/members#references) ### RegisterType static · 4 overloads · since v2.20 | Overload | Description | |---|---| | [RegisterType<T>()](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-t1)static · since v2.20 | Registers the type defined by `T` as the node object type to create in case there a node instance is to be created for the type definition identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) defined on the `T` specified. | | [RegisterType(Type)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-system-type)static · since v2.20 | Registers the `nodeType` specified as the node object type to create in case there a node instance is to be created for the type node identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) defined on the `nodeType` specified. | | [RegisterType<T>(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-t1-opc-uafx-opcnodeid)static · since v2.20 | Registers the type defined by `T` as the node object type to create in case there a node instance is to be created for the type definition identified by the `nodeTypeId` specified. | | [RegisterType(Type, OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-system-type-opc-uafx-opcnodeid)static · since v2.20 | Registers the `nodeType` specified as the node object type to create in case there a node instance is to be created for the type node identified by the `nodeTypeId` specified. | #### RegisterType<T>() static · since v2.20 Registers the type defined by `T` as the node object type to create in case there a node instance is to be created for the type definition identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) defined on the `T` specified.
```csharp public static void RegisterType() ```
```vbnet Public Shared Sub RegisterType(Of T)() ```
**Type parameters** | Name | Description | |---|---| | `T` | The type to use in case there a node object for the node type equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. The type needs be a subclass of the [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) class. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The type `T` uses any node type specific attribute which offers invalid information about the node type to associate with the [Type](https://learn.microsoft.com/dotnet/api/system.type). | #### RegisterType(Type) static · since v2.20 Registers the `nodeType` specified as the node object type to create in case there a node instance is to be created for the type node identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) defined on the `nodeType` specified.
```csharp public static void RegisterType(Type nodeType) ```
```vbnet Public Shared Sub RegisterType(nodeType As Type) ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeType` | [Type](https://learn.microsoft.com/dotnet/api/system.type) | The [Type](https://learn.microsoft.com/dotnet/api/system.type) to use in case there a node object for the node type equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. The type needs be a subclass of the [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) class. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The `nodeType` uses any node type specific attribute which offers invalid information about the node type to associate with the [Type](https://learn.microsoft.com/dotnet/api/system.type). | | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeType` is a null reference (Nothing in Visual Basic). | #### RegisterType<T>(OpcNodeId) static · since v2.20 Registers the type defined by `T` as the node object type to create in case there a node instance is to be created for the type definition identified by the `nodeTypeId` specified.
```csharp public static void RegisterType(OpcNodeId nodeTypeId) ```
```vbnet Public Shared Sub RegisterType(Of T)(nodeTypeId As OpcNodeId) ```
**Type parameters** | Name | Description | |---|---| | `T` | The type to use in case there a node object for the node type equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. The type needs be a subclass of the [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) class. | **Parameters** | Name | Type | Description | |---|---|---| | `nodeTypeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The identifier of the type node for which the `T` is to be used to create a node object instance. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The type `T` uses any node type specific attribute which offers invalid information about the node type to associate with the [Type](https://learn.microsoft.com/dotnet/api/system.type). | | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeTypeId` is a null reference (Nothing in Visual Basic). | **Remarks** It is not possible to register the same or a different node type for the `nodeTypeId` specified as long there is already a node type registered for the type node specified by `nodeTypeId`. #### RegisterType(Type, OpcNodeId) static · since v2.20 Registers the `nodeType` specified as the node object type to create in case there a node instance is to be created for the type node identified by the `nodeTypeId` specified.
```csharp public static void RegisterType(Type nodeType, OpcNodeId nodeTypeId) ```
```vbnet Public Shared Sub RegisterType(nodeType As Type, nodeTypeId As OpcNodeId) ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeType` | [Type](https://learn.microsoft.com/dotnet/api/system.type) | The [Type](https://learn.microsoft.com/dotnet/api/system.type) to use in case there a node object for the node type equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. The type needs be a subclass of the [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) class. | | `nodeTypeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The identifier of the type node for which the `nodeType` is to be used to create a node object instance. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The `nodeType` uses any node type specific attribute which offers invalid information about the node type to associate with the [Type](https://learn.microsoft.com/dotnet/api/system.type). | | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeType` or `nodeTypeId` is a null reference (Nothing in Visual Basic). | **Remarks** It is not possible to register the same or a different node type for the `nodeTypeId` specified as long there is already a node type registered for the type node specified by `nodeTypeId`. ### RegisterTypes static · 3 overloads · since v2.20 | Overload | Description | |---|---| | [RegisterTypes(Assembly)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-reflection-assembly)static · since v2.20 | Registers all non-abstract types in the `assembly` specified which defines the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/). | | [RegisterTypes(IEnumerable<Type>)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-collections-generic-ienumerable-of-system-type)static · since v2.20 | Registers the `nodeTypes` specified as the node object type to create in case there a node instance is to be created for the type nodes identified by the [OpcEventTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventtypeattribute/) used on one of the `nodeTypes` specified. | | [RegisterTypes(Type, params Type\[\])](#registertypes-system-type-system-type-array)static · since v2.20 | Registers the `nodeType` and the further specified `nodeTypes` as the node object type to create in case there a node instance is to be created for the type node identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) used on the `nodeType` or on one of the `nodeTypes` specified. | **Exceptions (all overloads)** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | A [Type](https://learn.microsoft.com/dotnet/api/system.type) does not use any node type specific attribute which offers invalid information about the node type to associate with the [Type](https://learn.microsoft.com/dotnet/api/system.type). | #### RegisterTypes(Assembly) static · since v2.20 Registers all non-abstract types in the `assembly` specified which defines the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/).
```csharp public static void RegisterTypes(Assembly assembly) ```
```vbnet Public Shared Sub RegisterTypes(assembly As Assembly) ```
**Parameters** | Name | Type | Description | |---|---|---| | `assembly` | [Assembly](https://learn.microsoft.com/dotnet/api/system.reflection.assembly) | The [Assembly](https://learn.microsoft.com/dotnet/api/system.reflection.assembly) its types are inspected for types which using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/). | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `assembly` is a null reference (Nothing in Visual Basic). | **Remarks** The [Type](https://learn.microsoft.com/dotnet/api/system.type) instances to register need to define the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) and needs to be a subclass of the [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) class. #### RegisterTypes(IEnumerable<Type>) static · since v2.20 Registers the `nodeTypes` specified as the node object type to create in case there a node instance is to be created for the type nodes identified by the [OpcEventTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventtypeattribute/) used on one of the `nodeTypes` specified.
```csharp public static void RegisterTypes(IEnumerable nodeTypes) ```
```vbnet Public Shared Sub RegisterTypes(nodeTypes As IEnumerable(Of Type)) ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeTypes` | [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)<[Type](https://learn.microsoft.com/dotnet/api/system.type)> | A sequence of [Type](https://learn.microsoft.com/dotnet/api/system.type) instances representing the types to use in case there a node object for the node type equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeTypes` is a null reference (Nothing in Visual Basic). | **Remarks** Any null reference (Nothing in Visual Basic) in `nodeTypes` is ignored. #### RegisterTypes(Type, params Type\[\]) static · since v2.20 Registers the `nodeType` and the further specified `nodeTypes` as the node object type to create in case there a node instance is to be created for the type node identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) used on the `nodeType` or on one of the `nodeTypes` specified.
```csharp public static void RegisterTypes(Type nodeType, params Type[] nodeTypes) ```
```vbnet Public Shared Sub RegisterTypes( nodeType As Type, ParamArray nodeTypes As Type()) ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeType` | [Type](https://learn.microsoft.com/dotnet/api/system.type) | The [Type](https://learn.microsoft.com/dotnet/api/system.type) instance to use in case there a node object for the node type equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. | | `nodeTypes` | params [Type](https://learn.microsoft.com/dotnet/api/system.type)[] | An array of additional [Type](https://learn.microsoft.com/dotnet/api/system.type) instances to use in case there a node object for the node types equals to the node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) is to be created. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeType` or `nodeTypes` is a null reference (Nothing in Visual Basic). | ### RemoveNotifier virtual Removes the `node` from the collection of notifiers (= event sources) of this node.
```csharp public virtual void RemoveNotifier(OpcContext context, IOpcNode node) ```
```vbnet Public Overridable Sub RemoveNotifier(context As OpcContext, node As IOpcNode) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to remove the `node` as the notifying event source. | | `node` | [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) | The [IOpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/) instance no longer acting as the notifier. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` or `node` is a null reference (Nothing in Visual Basic). | **Implements** [RemoveNotifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcnode/members#removenotifier) ### ReportEvent Reports the `eventData` specified to all nodes this [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) is a notifier of.
```csharp public void ReportEvent(OpcContext context, OpcEvent eventData) ```
```vbnet Public Sub ReportEvent(context As OpcContext, eventData As OpcEvent) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to notify about the `eventData`. | | `eventData` | [OpcEvent](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcevent/) | The [OpcEvent](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcevent/) instance to report. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The `eventData` does not provide a [OpcEventNodeSnapshot](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventnodesnapshot/). | | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` or `eventData` is a null reference (Nothing in Visual Basic). | ### ResolveModel protected · virtual · since v2.54 Resolves the [Model](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#model) of the node.
```csharp protected virtual OpcNodeModel ResolveModel() ```
```vbnet Protected Overridable Function ResolveModel() As OpcNodeModel ```
**Returns** [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) The [OpcNodeModel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/) assigned to the node, the model of the child with the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#name) of the node within the [Model](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#model) of its parent node or [None](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodemodel/members#none) if neither of them is available. ### ResumeModelChangeEvents since v2.50 Resumes model change tracking and events for this [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) and optionally for all children.
```csharp public void ResumeModelChangeEvents(bool recursive = false) ```
```vbnet Public Sub ResumeModelChangeEvents(recursive As Boolean = False) ```
**Parameters** | Name | Type | Description | |---|---|---| | `recursive` | [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) | The value `true` if model changes are to be resumed for all children as well; otherwise the value `false`. Optional, default `false`. | ### SuspendModelChangeEvents since v2.50 Temporarily suspends model change tracking and events for this [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) and optionally for all children.
```csharp public void SuspendModelChangeEvents(bool recursive = false) ```
```vbnet Public Sub SuspendModelChangeEvents(recursive As Boolean = False) ```
**Parameters** | Name | Type | Description | |---|---|---| | `recursive` | [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) | The value `true` if model changes are to be suspended for all children as well; otherwise the value `false`. Optional, default `false`. | ### UnregisterType static · 2 overloads · since v2.20 | Overload | Description | |---|---| | [UnregisterType<T>()](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#unregistertype-t1)static · since v2.20 | Unregisters the previously registered (see [RegisterType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-t1)) type defined by `T` as the [object](https://learn.microsoft.com/dotnet/api/system.object) type to not longer create for the type node identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) defined on the `T` specified. | | [UnregisterType<T>(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#unregistertype-t1-opc-uafx-opcnodeid)static · since v2.20 | Unregisters the previously registered (see [RegisterType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-t1-opc-uafx-opcnodeid)) type defined by `T` as the [object](https://learn.microsoft.com/dotnet/api/system.object) type to not longer create for the type node identified by the `nodeTypeId` specified. | #### UnregisterType<T>() static · since v2.20 Unregisters the previously registered (see [RegisterType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-t1)) type defined by `T` as the [object](https://learn.microsoft.com/dotnet/api/system.object) type to not longer create for the type node identified by the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/) defined on the `T` specified.
```csharp public static void UnregisterType() ```
```vbnet Public Shared Sub UnregisterType(Of T)() ```
**Type parameters** | Name | Description | |---|---| | `T` | The node type to unregister for the node type equals to node type identifier defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/). | #### UnregisterType<T>(OpcNodeId) static · since v2.20 Unregisters the previously registered (see [RegisterType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertype-t1-opc-uafx-opcnodeid)) type defined by `T` as the [object](https://learn.microsoft.com/dotnet/api/system.object) type to not longer create for the type node identified by the `nodeTypeId` specified.
```csharp public static void UnregisterType(OpcNodeId nodeTypeId) ```
```vbnet Public Shared Sub UnregisterType(Of T)(nodeTypeId As OpcNodeId) ```
**Type parameters** | Name | Description | |---|---| | `T` | The node type to unregister for the node type equals to `nodeTypeId`. | **Parameters** | Name | Type | Description | |---|---|---| | `nodeTypeId` | [OpcNodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeid/) | The identifier of the type node for which the `T` is to be unregistered. | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeTypeId` is a null reference (Nothing in Visual Basic). | ### UnregisterTypes static · 3 overloads · since v2.20 | Overload | Description | |---|---| | [UnregisterTypes(Assembly)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#unregistertypes-system-reflection-assembly)static · since v2.20 | Unregisters all previously registered types (see [RegisterTypes](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-reflection-assembly)) in the `assembly` specified. | | [UnregisterTypes(IEnumerable<Type>)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#unregistertypes-system-collections-generic-ienumerable-of-system-type)static · since v2.20 | Unregisters the previously registered (see [RegisterTypes](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-collections-generic-ienumerable-of-system-type)) `nodeTypes` specified. | | [UnregisterTypes(Type, params Type\[\])](#unregistertypes-system-type-system-type-array)static · since v2.20 | Unregisters the previously registered `nodeType` and the further specified `nodeTypes` (see [RegisterTypes](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-type-system-type-array)). | #### UnregisterTypes(Assembly) static · since v2.20 Unregisters all previously registered types (see [RegisterTypes](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-reflection-assembly)) in the `assembly` specified.
```csharp public static void UnregisterTypes(Assembly assembly) ```
```vbnet Public Shared Sub UnregisterTypes(assembly As Assembly) ```
**Parameters** | Name | Type | Description | |---|---|---| | `assembly` | [Assembly](https://learn.microsoft.com/dotnet/api/system.reflection.assembly) | The [Assembly](https://learn.microsoft.com/dotnet/api/system.reflection.assembly) its types are inspected for types using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/). | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `assembly` is a null reference (Nothing in Visual Basic). | #### UnregisterTypes(IEnumerable<Type>) static · since v2.20 Unregisters the previously registered (see [RegisterTypes](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-collections-generic-ienumerable-of-system-type)) `nodeTypes` specified.
```csharp public static void UnregisterTypes(IEnumerable nodeTypes) ```
```vbnet Public Shared Sub UnregisterTypes(nodeTypes As IEnumerable(Of Type)) ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeTypes` | [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)<[Type](https://learn.microsoft.com/dotnet/api/system.type)> | A sequence of [Type](https://learn.microsoft.com/dotnet/api/system.type) instances to unregister for the node types equals to the node type identifiers defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/). | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeTypes` is a null reference (Nothing in Visual Basic). | #### UnregisterTypes(Type, params Type\[\]) static · since v2.20 Unregisters the previously registered `nodeType` and the further specified `nodeTypes` (see [RegisterTypes](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#registertypes-system-type-system-type-array)).
```csharp public static void UnregisterTypes(Type nodeType, params Type[] nodeTypes) ```
```vbnet Public Shared Sub UnregisterTypes( nodeType As Type, ParamArray nodeTypes As Type()) ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeType` | [Type](https://learn.microsoft.com/dotnet/api/system.type) | The [Type](https://learn.microsoft.com/dotnet/api/system.type) instance to unregister for the node types equals to the node type identifiers defined using the [OpcNodeTypeAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodetypeattribute/). | | `nodeTypes` | params [Type](https://learn.microsoft.com/dotnet/api/system.type)[] | | **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeType` or `nodeTypes` is a null reference (Nothing in Visual Basic). | ### UpdateChanges 2 overloads · since v2.10 | Overload | Description | |---|---| | [UpdateChanges(OpcContext, OpcNodeChanges)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#updatechanges-opc-uafx-opccontext-opc-uafx-opcnodechanges)since v2.10 | Notifies about the `changes` on behalf of the node and removes pending changes which intersect with the `changes` specified. | | [UpdateChanges(OpcContext, OpcNodeChanges, bool)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#updatechanges-opc-uafx-opccontext-opc-uafx-opcnodechanges-system-boolean)since v2.10 | Notifies about the `changes` on behalf of the node (and optionally on its children) and removes pending changes which intersect with the `changes` specified. | **Exceptions (all overloads)** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `context` is a null reference (Nothing in Visual Basic). | #### UpdateChanges(OpcContext, OpcNodeChanges) since v2.10 Notifies about the `changes` on behalf of the node and removes pending changes which intersect with the `changes` specified.
```csharp public void UpdateChanges(OpcContext context, OpcNodeChanges changes) ```
```vbnet Public Sub UpdateChanges(context As OpcContext, changes As OpcNodeChanges) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to notify about the `changes`. | | `changes` | [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) | A bitwise combination of [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) members to use to notify changes on behalf of the node. | **Remarks** This method influences the value of the properties [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) and [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#haspendingchanges). #### UpdateChanges(OpcContext, OpcNodeChanges, bool) since v2.10 Notifies about the `changes` on behalf of the node (and optionally on its children) and removes pending changes which intersect with the `changes` specified.
```csharp public void UpdateChanges( OpcContext context, OpcNodeChanges changes, bool recursive) ```
```vbnet Public Sub UpdateChanges( context As OpcContext, changes As OpcNodeChanges, recursive As Boolean) ```
**Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) | The [OpcContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opccontext/) to use to notify about changes performed on the node. | | `changes` | [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) | A bitwise combination of [OpcNodeChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechanges/) members to use to notify changes on behalf of the node (and its children). | | `recursive` | [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) | The value true if the `changes` are to be notified for all children as well; otherwise the value false. | **Remarks** This method influences the value of the properties [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) and [HasPendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#haspendingchanges). ### WriteAttributeValueCore protected · virtual Determines the value of the attribute to write. In case there a callback is assigned to write the value of the attribute (see [WriteDisplayNameCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#writedisplaynamecallback), [WriteDescriptionCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#writedescriptioncallback), [WriteUserWriteAccessCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#writeuserwriteaccesscallback) and [WriteWriteAccessCallback](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#writewriteaccesscallback)) the callback determines the value written; otherwise the `value` is returned.
```csharp protected virtual OpcAttributeValue WriteAttributeValueCore( OpcWriteAttributeValueContext context, OpcAttributeValue value) ```
```vbnet Protected Overridable Function WriteAttributeValueCore(Of T)( context As OpcWriteAttributeValueContext, value As OpcAttributeValue(Of T)) As OpcAttributeValue(Of T) ```
**Type parameters** | Name | Description | |---|---| | `T` | The type of attribute value to write. | **Parameters** | Name | Type | Description | |---|---|---| | `context` | [OpcWriteAttributeValueContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecontext/) | The [OpcWriteAttributeValueContext](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcwriteattributevaluecontext/) to use to write the attribute value. | | `value` | [OpcAttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/)<T> | The [OpcAttributeValue<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/) to write. | **Returns** [OpcAttributeValue](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/)<T> The [OpcAttributeValue<T>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattributevalue-1/) written. ## Events ### AfterAdded since v2.26 Occurs after the node has been added to the address space.
```csharp public event OpcNodeAddedEventHandler AfterAdded ```
```vbnet Public Event AfterAdded As OpcNodeAddedEventHandler ```
**Event type** [OpcNodeAddedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeaddedeventhandler/) ### AfterApplyChanges Occurs after one or more changes on the node has been notified.
```csharp public event OpcNodeChangesEventHandler AfterApplyChanges ```
```vbnet Public Event AfterApplyChanges As OpcNodeChangesEventHandler ```
**Event type** [OpcNodeChangesEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventhandler/) **Remarks** The changes notified either belong to the [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) or to changes on behalf of the node. ### BeforeAdded since v2.26 Occurs before the node is added to the address space.
```csharp public event OpcNodeAddedEventHandler BeforeAdded ```
```vbnet Public Event BeforeAdded As OpcNodeAddedEventHandler ```
**Event type** [OpcNodeAddedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeaddedeventhandler/) ### BeforeApplyChanges Occurs before one or more changes on the node are notified.
```csharp public event OpcNodeChangesEventHandler BeforeApplyChanges ```
```vbnet Public Event BeforeApplyChanges As OpcNodeChangesEventHandler ```
**Event type** [OpcNodeChangesEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventhandler/) **Remarks** The changes notified either belong to the [PendingChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#pendingchanges) or to changes on behalf of the node. ### ChangesUnhandled since v2.50 Occurs when changes applied with [ApplyChanges](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#applychanges-opc-uafx-opccontext) are not monitored or discarded by all monitored items.
```csharp public event OpcNodeChangesEventHandler ChangesUnhandled ```
```vbnet Public Event ChangesUnhandled As OpcNodeChangesEventHandler ```
**Event type** [OpcNodeChangesEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodechangeseventhandler/) ### EventReported since v2.54 Occurs after an event has been reported using [ReportEvent](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members#reportevent).
```csharp public event OpcNodeEventReportedEventHandler EventReported ```
```vbnet Public Event EventReported As OpcNodeEventReportedEventHandler ```
**Event type** [OpcNodeEventReportedEventHandler](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnodeeventreportedeventhandler/)