# OpcDataTypeSystem Members > Reference: Represents an encoding-based system which is organized in type dictionaries to define type information to use to understand data exchanged via OPC UA using a specific type of encoding.
Type
OpcDataTypeSystem
Namespace
Opc.UaFx
Assembly
Opc.UaFx.Advanced.dll
Package
Opc.UaFx.Advanced v2.59.0
Also in
Opc.UaFx.Client
Inherits members from [OpcTypeSystem<OpcDataTypeInfo>](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypesystem-1/members). ## Properties ### Binary static Gets the type system used for [Binary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/#binary) encoded type information offered by the Client or Server application.
```csharp public static OpcDataTypeSystem Binary { get; } ```
```vbnet Public Shared ReadOnly Property Binary As OpcDataTypeSystem ```
**Property value** [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) An instance of the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) class which contains the type dictionaries described by the [Type](https://learn.microsoft.com/dotnet/api/system.type)s using the [OpcDataTypeEncodingAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeencodingattribute/) with the [Binary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/#binary) encoding type implemented in the application which uses the OPC UA SDK. ### Default static Gets the default type system used by the OPC UA stack.
```csharp public static OpcDataTypeSystem Default { get; } ```
```vbnet Public Shared ReadOnly Property [Default] As OpcDataTypeSystem ```
**Property value** [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) An instance of the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) class which contains the type dictionaries used by default in Client and Server applications. **Remarks** The information offered by the default [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) is embedded in the OPC UA SDK and is therefore determined from the resources of the assembly whenever required. ### Empty static Gets the type system to use if their is no specific type system data available.
```csharp public static OpcDataTypeSystem Empty { get; } ```
```vbnet Public Shared ReadOnly Property Empty As OpcDataTypeSystem ```
**Property value** [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) An instance of the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) class which contains no type dictionary nor type information. ### EmptyDictionary Gets the type dictionary to use if their is no specific type dictionary data available, but the empty type dictionary shall refer to the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/).
```csharp public OpcDataTypeDictionary EmptyDictionary { get; } ```
```vbnet Public ReadOnly Property EmptyDictionary As OpcDataTypeDictionary ```
**Property value** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) An instance of the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) class which refers to the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). ### EncodingType Gets the type of encoding used for the data type dictionaries defined in the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/).
```csharp public OpcEncodingType EncodingType { get; } ```
```vbnet Public ReadOnly Property EncodingType As OpcEncodingType ```
**Property value** [OpcEncodingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/) One of the members defined by the [OpcEncodingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/) enumeration. ### FallbackDataTypeSystem since v2.21 Gets the data type system used as the fallback system to query data type information which is referenced in the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) but is not declared.
```csharp public OpcDataTypeSystem FallbackDataTypeSystem { get; } ```
```vbnet Public ReadOnly Property FallbackDataTypeSystem As OpcDataTypeSystem ```
**Property value** [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) An instance of the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) class used to query data type information which is referenced but not declared within the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) or a null reference (Nothing in Visual Basic) if the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) is independent from a different data type system. Such data type systems typically declare types which only reference others declared in the same system as well. ### HasCachedDictionaries protected Gets a value indicating whether the type system already has determined at least some type dictionaries offered as [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects.
```csharp protected bool HasCachedDictionaries { get; } ```
```vbnet Protected ReadOnly Property HasCachedDictionaries As Boolean ```
**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the system offers already prepared [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects; otherwise the value false. ### HasCachingCompleted protected · virtual Gets a value indicating whether the type system has determined all type dictionaries offered as [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects.
```csharp protected virtual bool HasCachingCompleted { get; } ```
```vbnet Protected Overridable Property HasCachingCompleted As Boolean ```
**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the system has completed its type dictionary retrieval and will use its internal cache to determine [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects; otherwise the value false. ### Name Gets a value which defines the human-readable name of the type system represented. A node which represents this [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) uses the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#name) as its [BrowseName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#browsename).
```csharp public OpcName Name { get; } ```
```vbnet Public ReadOnly Property Name As OpcName ```
**Property value** [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) An instance of the [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) class with the [string](https://learn.microsoft.com/dotnet/api/system.string) used as the name of the type system which does not unambiguously identify the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). ### NodeId Gets a value which identifies the type system represented. A node which represents this [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) uses the [NodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#nodeid) as its [NodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#nodeid).
```csharp public OpcNodeId NodeId { get; } ```
```vbnet Public ReadOnly Property NodeId 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 used as the identifier of the type system which unambiguously identifies the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). ### Xml static Gets the type system used for [Xml](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/#xml) encoded type information offered by the Client or Server application.
```csharp public static OpcDataTypeSystem Xml { get; } ```
```vbnet Public Shared ReadOnly Property Xml As OpcDataTypeSystem ```
**Property value** [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) An instance of the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) class which contains the type dictionaries described by the [Type](https://learn.microsoft.com/dotnet/api/system.type)s using the [OpcDataTypeEncodingAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeencodingattribute/) with the [Xml](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/#xml) encoding type implemented in the application which uses the OPC UA SDK. ## Methods ### GetDictionaries Retrieves all [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/).
```csharp public OpcDataTypeDictionary[] GetDictionaries() ```
```vbnet Public Function GetDictionaries() As OpcDataTypeDictionary() ```
**Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/)[] An array that contains all [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects that are offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). ### GetDictionary 4 overloads | Overload | Description | |---|---| | [GetDictionary(string)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionary-system-string) | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `nameOrNamespace` specified. | | [GetDictionary(OpcName)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionary-opc-uafx-opcname) | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `name` specified. | | [GetDictionary(OpcNamespace)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionary-opc-uafx-opcnamespace) | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `namespace` specified. | | [GetDictionary(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionary-opc-uafx-opcnodeid) | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which represents the type dictionary which is identified by the `nodeId` specified. | #### GetDictionary(string) Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `nameOrNamespace` specified.
```csharp public OpcDataTypeDictionary GetDictionary(string nameOrNamespace) ```
```vbnet Public Function GetDictionary( nameOrNamespace As String) As OpcDataTypeDictionary ```
**Parameters** | Name | Type | Description | |---|---|---| | `nameOrNamespace` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The [string](https://learn.microsoft.com/dotnet/api/system.string) to use to identify the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#name) (regarding its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/members#value)) or its [Namespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#namespace) (regarding its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamespace/members#value)) or its [XmlNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#xmlnamespace) is equals to the `nameOrNamespace` specified; otherwise a null reference (Nothing in Visual Basic). **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The `nameOrNamespace` is equals [Empty](https://learn.microsoft.com/dotnet/api/system.string.empty). | | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nameOrNamespace` is a null reference (Nothing in Visual Basic). | #### GetDictionary(OpcName) Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `name` specified.
```csharp public OpcDataTypeDictionary GetDictionary(OpcName name) ```
```vbnet Public Function GetDictionary(name As OpcName) As OpcDataTypeDictionary ```
**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 [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#name) is equals to the `name` specified; otherwise a null reference (Nothing in Visual Basic). **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `name` is a null reference (Nothing in Visual Basic). | #### GetDictionary(OpcNamespace) Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `namespace` specified.
```csharp public OpcDataTypeDictionary GetDictionary(OpcNamespace @namespace) ```
```vbnet Public Function GetDictionary( [namespace] As OpcNamespace) As OpcDataTypeDictionary ```
**Parameters** | Name | Type | Description | |---|---|---| | `namespace` | [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/) of the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object its [Namespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#namespace) is equals to the `namespace` specified; otherwise a null reference (Nothing in Visual Basic). **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `namespace` is a null reference (Nothing in Visual Basic). | #### GetDictionary(OpcNodeId) Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which represents the type dictionary which is identified by the `nodeId` specified.
```csharp public OpcDataTypeDictionary GetDictionary(OpcNodeId nodeId) ```
```vbnet Public Function GetDictionary(nodeId As OpcNodeId) As OpcDataTypeDictionary ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [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 [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `nodeId` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is associated with the `nodeId` specified. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `nodeId` is a null reference (Nothing in Visual Basic). | ### GetDictionaryCore protected · virtual · 4 overloads | Overload | Description | |---|---| | [GetDictionaryCore(string)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionarycore-system-string)protected · virtual | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `nameOrNamespace` specified. | | [GetDictionaryCore(OpcName)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionarycore-opc-uafx-opcname)protected · virtual | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `name` specified. | | [GetDictionaryCore(OpcNamespace)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionarycore-opc-uafx-opcnamespace)protected · virtual | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `namespace` specified. | | [GetDictionaryCore(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#getdictionarycore-opc-uafx-opcnodeid)protected · virtual | Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which represents the type dictionary which is identified by the `nodeId` specified. | #### GetDictionaryCore(string) protected · virtual Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `nameOrNamespace` specified.
```csharp protected virtual OpcDataTypeDictionary GetDictionaryCore( string nameOrNamespace) ```
```vbnet Protected Overridable Function GetDictionaryCore( nameOrNamespace As String) As OpcDataTypeDictionary ```
**Parameters** | Name | Type | Description | |---|---|---| | `nameOrNamespace` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The [string](https://learn.microsoft.com/dotnet/api/system.string) to use to identify the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#name) (regarding its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/members#value)) or its [Namespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#namespace) (regarding its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnamespace/members#value)) or its [XmlNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#xmlnamespace) is equals to the `nameOrNamespace` specified; otherwise a null reference (Nothing in Visual Basic). **Remarks** It is already assured that the passed `nameOrNamespace` is not a null reference (Nothing in Visual Basic) nor equals [Empty](https://learn.microsoft.com/dotnet/api/system.string.empty). In case there this method is not implemented in a derived class this method determines the type dictionary from a distinct and on-demand determined sequence which combines the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. #### GetDictionaryCore(OpcName) protected · virtual Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `name` specified.
```csharp protected virtual OpcDataTypeDictionary GetDictionaryCore(OpcName name) ```
```vbnet Protected Overridable Function GetDictionaryCore( name As OpcName) As OpcDataTypeDictionary ```
**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 [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#name) is equals to the `name` specified; otherwise a null reference (Nothing in Visual Basic). **Remarks** It is already assured that the passed `name` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type dictionary from a distinct and on-demand determined sequence which combines the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. #### GetDictionaryCore(OpcNamespace) protected · virtual Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `namespace` specified.
```csharp protected virtual OpcDataTypeDictionary GetDictionaryCore( OpcNamespace @namespace) ```
```vbnet Protected Overridable Function GetDictionaryCore( [namespace] As OpcNamespace) As OpcDataTypeDictionary ```
**Parameters** | Name | Type | Description | |---|---|---| | `namespace` | [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/) of the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object its [Namespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#namespace) is equals to the `namespace` specified; otherwise a null reference (Nothing in Visual Basic). **Remarks** It is already assured that the passed `namespace` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type dictionary from a distinct and on-demand determined sequence which combines the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. #### GetDictionaryCore(OpcNodeId) protected · virtual Retrieves the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which represents the type dictionary which is identified by the `nodeId` specified.
```csharp protected virtual OpcDataTypeDictionary GetDictionaryCore(OpcNodeId nodeId) ```
```vbnet Protected Overridable Function GetDictionaryCore( nodeId As OpcNodeId) As OpcDataTypeDictionary ```
**Parameters** | Name | Type | Description | |---|---|---| | `nodeId` | [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 [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) to retrieve. | **Returns** [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) The [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is known under the `nodeId` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) object which is associated with the `nodeId` specified. **Remarks** It is already assured that the passed `nodeId` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type dictionary from a distinct and on-demand determined sequence which combines the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. ### GetType 2 overloads | Overload | Description | |---|---| | [GetType(OpcEncoding)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettype-opc-uafx-opcencoding) | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type which is identified by the `encoding` specified. | | [GetType(XmlQualifiedName)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettype-system-xml-xmlqualifiedname) | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `xmlName` specified. | #### GetType(OpcEncoding) Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type which is identified by the `encoding` specified.
```csharp public OpcDataTypeInfo GetType(OpcEncoding encoding) ```
```vbnet Public Function [GetType](encoding As OpcEncoding) As OpcDataTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `encoding` | [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) | The [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) which identifies the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `encoding` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) which is associated with the `encoding` specified. **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `encoding` is a null reference (Nothing in Visual Basic). | #### GetType(XmlQualifiedName) Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `xmlName` specified.
```csharp public OpcDataTypeInfo GetType(XmlQualifiedName xmlName) ```
```vbnet Public Function [GetType](xmlName As XmlQualifiedName) As OpcDataTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `xmlName` | [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) | The [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) of the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object its [XmlName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#xmlname) is equals to the `xmlName` specified; otherwise a null reference (Nothing in Visual Basic). **Exceptions** | Exception | Condition | |---|---| | [ArgumentNullException](https://learn.microsoft.com/dotnet/api/system.argumentnullexception) | The `xmlName` is a null reference (Nothing in Visual Basic). | ### GetTypeCore protected · 6 overloads | Overload | Description | |---|---| | [GetTypeCore(OpcEncoding)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettypecore-opc-uafx-opcencoding)protected · virtual | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type which is identified by the `encoding` specified. | | [GetTypeCore(string)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettypecore-system-string)protected · override | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `name` specified. | | [GetTypeCore(OpcName)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettypecore-opc-uafx-opcname)protected · override | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `name` specified. | | [GetTypeCore(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettypecore-opc-uafx-opcnodeid)protected · override | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type which is identified by the `typeId` specified. | | [GetTypeCore(Type)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettypecore-system-type)protected · override | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type implemented by the `underlyingType` specified. | | [GetTypeCore(XmlQualifiedName)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#gettypecore-system-xml-xmlqualifiedname)protected · virtual | Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `xmlName` specified. | #### GetTypeCore(OpcEncoding) protected · virtual Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type which is identified by the `encoding` specified.
```csharp protected virtual OpcDataTypeInfo GetTypeCore(OpcEncoding encoding) ```
```vbnet Protected Overridable Function GetTypeCore( encoding As OpcEncoding) As OpcDataTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `encoding` | [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) | The [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) which identifies the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `encoding` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) which is associated with the `encoding` specified. **Remarks** It is already assured that the passed `encoding` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type from a distinct and on-demand determined sequence which combines the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects determined from the sequence of dictionaries offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. These dictionaries are then queried for the type information requested. #### GetTypeCore(string) protected · override Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `name` specified.
```csharp protected override OpcDataTypeInfo GetTypeCore(string name) ```
```vbnet Protected Overrides Function GetTypeCore(name As String) As OpcDataTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `name` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The [string](https://learn.microsoft.com/dotnet/api/system.string) to use to identify the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#name) is equals (regarding its [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/members#value)) to the `name` specified; otherwise a null reference (Nothing in Visual Basic). **Overrides** [GetTypeCore(string)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypesystem-1/members#gettypecore-system-string) **Remarks** It is already assured that the passed `name` is not a null reference (Nothing in Visual Basic) nor equals [Empty](https://learn.microsoft.com/dotnet/api/system.string.empty). In case there this method is not implemented in a derived class this method determines the type from a distinct and on-demand determined sequence which combines the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects determined from the sequence of dictionaries offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. These dictionaries are then queried for the type information requested. #### GetTypeCore(OpcName) protected · override Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `name` specified.
```csharp protected override OpcDataTypeInfo GetTypeCore(OpcName name) ```
```vbnet Protected Overrides Function GetTypeCore(name As OpcName) As OpcDataTypeInfo ```
**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 [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object its [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#name) is equals to the `name` specified; otherwise a null reference (Nothing in Visual Basic). **Overrides** [GetTypeCore(OpcName)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypesystem-1/members#gettypecore-opc-uafx-opcname) **Remarks** It is already assured that the passed `name` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type from a distinct and on-demand determined sequence which combines the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects determined from the sequence of dictionaries offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. These dictionaries are then queried for the type information requested. #### GetTypeCore(OpcNodeId) protected · override Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type which is identified by the `typeId` specified.
```csharp protected override OpcDataTypeInfo GetTypeCore(OpcNodeId typeId) ```
```vbnet Protected Overrides Function GetTypeCore(typeId As OpcNodeId) As OpcDataTypeInfo ```
**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 [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `typeId` specified or a null reference (Nothing in Visual Basic) if there doesn't exist a known [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is associated with the `typeId` specified. **Overrides** [GetTypeCore(OpcNodeId)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypesystem-1/members#gettypecore-opc-uafx-opcnodeid) **Remarks** It is already assured that the passed `typeId` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type from a distinct and on-demand determined sequence which combines the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects determined from the sequence of dictionaries offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. These dictionaries are then queried for the type information requested. #### GetTypeCore(Type) protected · override Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the type implemented by the `underlyingType` specified.
```csharp protected override OpcDataTypeInfo GetTypeCore(Type underlyingType) ```
```vbnet Protected Overrides Function GetTypeCore( underlyingType As Type) As OpcDataTypeInfo ```
**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 [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which declares the `underlyingType` specified or a null reference (Nothing in Visual Basic) if there isn't a [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object associated with the `underlyingType` specified. **Overrides** [GetTypeCore(Type)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypesystem-1/members#gettypecore-system-type) **Remarks** It is already assured that the passed `underlyingType` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type from a distinct and on-demand determined sequence which combines the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects determined from the sequence of dictionaries offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. These dictionaries are then queried for the type information requested. #### GetTypeCore(XmlQualifiedName) protected · virtual Retrieves the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object which is known under the `xmlName` specified.
```csharp protected virtual OpcDataTypeInfo GetTypeCore(XmlQualifiedName xmlName) ```
```vbnet Protected Overridable Function GetTypeCore( xmlName As XmlQualifiedName) As OpcDataTypeInfo ```
**Parameters** | Name | Type | Description | |---|---|---| | `xmlName` | [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) | The [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) of the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object to retrieve. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) The [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object its [XmlName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#xmlname) is equals to the `xmlName` specified; otherwise a null reference (Nothing in Visual Basic). **Remarks** It is already assured that the passed `xmlName` is not a null reference (Nothing in Visual Basic). In case there this method is not implemented in a derived class this method determines the type from a distinct and on-demand determined sequence which combines the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects determined from the sequence of dictionaries offered by [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams) and [RetrieveDictionariesCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary). Both methods are called only once and their output is cached for subsequent type dictionary retrieval. These dictionaries are then queried for the type information requested. ### GetTypesCore protected · override · since v2.9 Retrieves all [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects offered by the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) .
```csharp protected override OpcDataTypeInfo[] GetTypesCore() ```
```vbnet Protected Overrides Function GetTypesCore() As OpcDataTypeInfo() ```
**Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/)[] An array that contains all [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) objects that are offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). **Overrides** [GetTypesCore()](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypesystem-1/members#gettypescore) ### Of static Retrieves the type system used for the `encodingType` specified which provides encoded type information offered by the Client or Server application.
```csharp public static OpcDataTypeSystem Of(OpcEncodingType encodingType) ```
```vbnet Public Shared Function [Of]( encodingType As OpcEncodingType) As OpcDataTypeSystem ```
**Parameters** | Name | Type | Description | |---|---|---| | `encodingType` | [OpcEncodingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/) | One of the members defined by the [OpcEncodingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/) enumeration which identifies the type system to retrieve. | **Returns** [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) An instance of the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) class which contains the type dictionaries described by the [Type](https://learn.microsoft.com/dotnet/api/system.type)s using the [OpcDataTypeEncodingAttribute](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeencodingattribute/) with the [OpcEncodingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingtype/) specified by `encodingType` and implemented in the application which uses the OPC UA SDK. ### RetrieveDictionariesCore protected · 2 overloads · since v2.9 | Overload | Description | |---|---| | [RetrieveDictionariesCore()](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-noparams)protected · since v2.9 | Retrieves all [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects explictly offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). | | [RetrieveDictionariesCore(IList<OpcDataTypeDictionary>)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#retrievedictionariescore-system-collections-generic-ilist-of-opc-uafx-opcdatatypedictionary)protected · virtual · since v2.9 | When implemented in a derived class, retrieves all [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects on-demand offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) except the already `knownDictionaries` specified. | #### RetrieveDictionariesCore() protected · since v2.9 Retrieves all [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects explictly offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/).
```csharp protected IList RetrieveDictionariesCore() ```
```vbnet Protected Function RetrieveDictionariesCore() As IList(Of OpcDataTypeDictionary) ```
**Returns** [IList](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1)<[OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/)> A list of explictly offered [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects. #### RetrieveDictionariesCore(IList<OpcDataTypeDictionary>) protected · virtual · since v2.9 When implemented in a derived class, retrieves all [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects on-demand offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) except the already `knownDictionaries` specified.
```csharp protected virtual IEnumerable RetrieveDictionariesCore( IList knownDictionaries) ```
```vbnet Protected Overridable Function RetrieveDictionariesCore( knownDictionaries As IList(Of OpcDataTypeDictionary)) As IEnumerable(Of OpcDataTypeDictionary) ```
**Parameters** | Name | Type | Description | |---|---|---| | `knownDictionaries` | [IList](https://learn.microsoft.com/dotnet/api/system.collections.generic.ilist-1)<[OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/)> | The list of already known [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects which shall not be offered. | **Returns** [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)<[OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/)> A sequence of [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) objects offered by the [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/) except the type dictionaries in `knownDictionaries`. ### ToString override Returns a [string](https://learn.microsoft.com/dotnet/api/system.string) representing the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#name) of the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/).
```csharp public override string ToString() ```
```vbnet Public Overrides Function ToString() As String ```
**Returns** [String](https://learn.microsoft.com/dotnet/api/system.string) A [string](https://learn.microsoft.com/dotnet/api/system.string) representing the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/members#name) of the current [OpcDataTypeSystem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypesystem/). **Overrides** [ToString()](https://learn.microsoft.com/dotnet/api/system.object.tostring)