# OpcDataTypeInfo Members > Reference: Represents type declarations used for data types.

Type: OpcDataTypeInfo
Namespace: Opc.UaFx
Assembly: Opc.UaFx.Advanced.dll
Package: Opc.UaFx.Advanced v2.59.0
Also in: Opc.UaFx.Client

## Properties ### BaseType virtual Gets the type from which the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) directly inherits.

```csharp public virtual OpcDataTypeInfo BaseType { get; } ```

```vbnet Public Overridable ReadOnly Property BaseType As OpcDataTypeInfo ```

**Property value** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) An instance of the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) which represents the type from which the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) directly inherits or a null reference (Nothing in Visual Basic) if the type does not inherit from a different [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). ### ByteOrder virtual Gets the byte order of the data represented by the type.

```csharp public virtual OpcByteOrder? ByteOrder { get; } ```

```vbnet Public Overridable ReadOnly Property ByteOrder As OpcByteOrder? ```

**Property value** [Nullable](https://learn.microsoft.com/dotnet/api/system.nullable-1)<[OpcByteOrder](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcbyteorder/)> One of the members defined by the [OpcByteOrder](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcbyteorder/) enumeration which overrides the [ByteOrder](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#byteorder) of its [TypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#typedictionary) or a null reference (Nothing in Visual Basic) if the [OpcByteOrder](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcbyteorder/) is to be used from the [TypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#typedictionary) of this type. ### Category Gets the category the [IOpcType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopctype/) falls within.

```csharp public OpcTypeCategory Category { get; } ```

```vbnet Public ReadOnly Property Category As OpcTypeCategory ```

**Property value** [OpcTypeCategory](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypecategory/) One of the members defined by the [OpcTypeCategory](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypecategory/) enumeration. **Implements** [Category](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopctype/members#category) **Remarks** This implementation always returns [DataType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctypecategory/#datatype). ### CustomAttributes virtual Gets an array of custom attributes associated with this type.

```csharp public virtual string[] CustomAttributes { get; } ```

```vbnet Public Overridable ReadOnly Property CustomAttributes As String() ```

**Property value** [String](https://learn.microsoft.com/dotnet/api/system.string)[] An array of [string](https://learn.microsoft.com/dotnet/api/system.string) values used by the author of this type. **Remarks** Applications are not be required to understand these attributes in order to interpret an encoded instance of the type. ### Declarations virtual · since v2.26 Gets a value indicating the ways used to declare the data type represented.

```csharp public virtual OpcDataTypeDeclarations Declarations { get; } ```

```vbnet Public Overridable ReadOnly Property Declarations As OpcDataTypeDeclarations ```

**Property value** [OpcDataTypeDeclarations](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedeclarations/) One or a combination of the members defined by the [OpcDataTypeDeclarations](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedeclarations/) enumeration. ### Documentation virtual · since v2.9 Gets any semantic information that would help a human to understand what the type represents.

```csharp public virtual string Documentation { get; } ```

```vbnet Public Overridable ReadOnly Property Documentation As String ```

**Property value** [String](https://learn.microsoft.com/dotnet/api/system.string) A human readable text that describes the type and that would help a human to understand what the type represents. ### Empty static Gets the type to use if their is no specific type data available.

```csharp public static OpcDataTypeInfo Empty { get; } ```

```vbnet Public Shared ReadOnly Property Empty As OpcDataTypeInfo ```

**Property value** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) An instance of the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) class which refers to the [Empty](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#empty). ### Encoding Gets the information used to identify the type of encoding used for the data of the type represented.

```csharp public OpcEncoding Encoding { get; } ```

```vbnet Public ReadOnly Property Encoding As OpcEncoding ```

**Property value** [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) An instance of the [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) class which represents the information used to encode data of the type or a null reference (Nothing in Visual Basic) if is no encoding information associated with the type. **Implements** [Encoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#encoding) ### EncodingMask virtual Gets the characteristics used to encode the existence of optional fields.

```csharp public virtual OpcEncodingMask EncodingMask { get; } ```

```vbnet Public Overridable ReadOnly Property EncodingMask As OpcEncodingMask ```

**Property value** [OpcEncodingMask](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingmask/) An instance of the [OpcEncodingMask](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencodingmask/) class. **Implements** [EncodingMask](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#encodingmask) ### Encodings virtual Gets information of all encodings supported by the type represented.

```csharp public virtual OpcEncoding[] Encodings { get; } ```

```vbnet Public Overridable ReadOnly Property Encodings As OpcEncoding() ```

**Property value** [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/)[] An array of [OpcEncoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcencoding/) instances supported by the type. **Implements** [Encodings](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#encodings) ### IsArray virtual Gets a value indicating whether the type is an array.

```csharp public virtual bool IsArray { get; } ```

```vbnet Public Overridable ReadOnly Property IsArray As Boolean ```

**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the current type is an array; otherwise the value false. **Implements** [IsArray](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#isarray) ### IsEmpty virtual Gets a value indicating whether the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents a type to use if there is no specific type described.

```csharp public virtual bool IsEmpty { get; } ```

```vbnet Public Overridable ReadOnly Property IsEmpty As Boolean ```

**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the type does not declare a specific type; otherwise the value false. ### IsEnum virtual Gets a value indicating whether the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents an enumeration.

```csharp public virtual bool IsEnum { get; } ```

```vbnet Public Overridable ReadOnly Property IsEnum As Boolean ```

**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents an enumeration; otherwise the value false. **Implements** [IsEnum](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#isenum) **Remarks** The OPC UA handles enumerations as a numeric value that has a fixed set of valid values. The encoded value described by an enumeration is always an unsigned integer (see [uint](https://learn.microsoft.com/dotnet/api/system.uint32)) with a fixed size. ### IsOpaque virtual Gets a value indicating whether the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) describes a primitive fixed size type.

```csharp public virtual bool IsOpaque { get; } ```

```vbnet Public Overridable ReadOnly Property IsOpaque As Boolean ```

```csharp public virtual bool IsPrimitive { get; } ```

```vbnet Public Overridable ReadOnly Property IsPrimitive As Boolean ```

```csharp public virtual bool IsStruct { get; } ```

```vbnet Public Overridable ReadOnly Property IsStruct As Boolean ```

**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) is a structured type; otherwise the value false. **Implements** [IsStruct](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#isstruct) **Remarks** The OPC UA handles structures as a sequence of values. Each value in the sequence is called a field. A field may specify that zero, one or multiple instances of the type appear within the sequence described by the structure. Some fields have lengths that are not multiples of 8 bits. Several of these fields may appear in a sequence in a structure, however, the total number of bits used in the sequence shall be aligned on a byte boundary. A sequence of fields which do not line up on byte boundaries are specified from the least significant bit to the most significant bit. Sequences which are longer than one byte overflow from the most significant bit to the first byte into the least significant bit of the next byte. ### IsSystemType virtual Gets a value indicating whether the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents one of the predefined built-in data types defined by the OPC UA.

```csharp public virtual bool IsSystemType { get; } ```

```vbnet Public Overridable ReadOnly Property IsSystemType As Boolean ```

**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the current data type represents a OPC UA is a built-in type; otherwise the value false. **Implements** [IsSystemType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#issystemtype) ### IsUnion virtual · since v2.32 Gets a value indicating whether the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents a type which is only transported using a field indicator and the field indicated.

```csharp public virtual bool IsUnion { get; } ```

```vbnet Public Overridable ReadOnly Property IsUnion As Boolean ```

**Property value** [Boolean](https://learn.microsoft.com/dotnet/api/system.boolean) The value true if the current data type represents an union type; otherwise the value false. **Implements** [IsUnion](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#isunion) ### IsUnknown virtual Gets a value indicating whether the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) acts as a placeholder for a referenced type its type declaration could not resolved.

```csharp public virtual bool IsUnknown { get; } ```

```vbnet Public Overridable ReadOnly Property IsUnknown As Boolean ```

```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 which does not unambiguously identify the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). **Implements** [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopctype/members#name), [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#name) ### Size virtual Gets the size of the type represented as the number of bytes required.

```csharp public virtual long? Size { get; } ```

```vbnet Public Overridable ReadOnly Property Size As Long? ```

**Property value** [Nullable](https://learn.microsoft.com/dotnet/api/system.nullable-1)<[Int64](https://learn.microsoft.com/dotnet/api/system.int64)> The size of the type as the number of bytes required; if this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents a type with a fixed size (see [IsOpaque](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#isopaque)). **Implements** [Size](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#size) ### SizeInBits virtual Gets the size of the type represented as the number of bits required.

```csharp public virtual long? SizeInBits { get; } ```

```vbnet Public Overridable ReadOnly Property SizeInBits As Long? ```

**Property value** [Nullable](https://learn.microsoft.com/dotnet/api/system.nullable-1)<[Int64](https://learn.microsoft.com/dotnet/api/system.int64)> The size of the type as the number of bits required; if this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) represents a type with a fixed size (see [IsOpaque](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#isopaque)). **Implements** [SizeInBits](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#sizeinbits) ### TypeDictionary Gets the the [OpcDataTypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/) which conains the data type declaration represented.

```csharp public OpcDataTypeDictionary TypeDictionary { get; } ```

```vbnet Public ReadOnly Property TypeDictionary 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 defines the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). ### TypeId Gets a value which identifies the type represented. A node which represents this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) uses the [TypeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#typeid) as its [NodeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcattribute/#nodeid).

```csharp public OpcNodeId TypeId { get; } ```

```vbnet Public ReadOnly Property TypeId 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 which unambiguously identifies the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). **Implements** [TypeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopctype/members#typeid), [TypeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#typeid) ### UnderlyingType Gets the type which provides the implementation of the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/).

```csharp public Type UnderlyingType { get; } ```

```vbnet Public ReadOnly Property UnderlyingType As Type ```

**Property value** [Type](https://learn.microsoft.com/dotnet/api/system.type) The [Type](https://learn.microsoft.com/dotnet/api/system.type) which implements the type declared or a null reference (Nothing in Visual Basic) if there does not exist a declaration of the type described by this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). **Implements** [UnderlyingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopctype/members#underlyingtype), [UnderlyingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#underlyingtype) ### XmlName Gets the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#name) of this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) qualified with the [XmlNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#xmlnamespace) of the [TypeDictionary](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#typedictionary) which conains the data type declaration represented.

```csharp public XmlQualifiedName XmlName { get; protected set; } ```

```vbnet Public Property XmlName As XmlQualifiedName ```

**Property value** [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) An instance of the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) class which identifies this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) using a full qualified name which includes the [XmlNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#xmlnamespace) and [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#name) of this type using the [Value](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/members#value) of the [OpcName](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcname/) used. **Remarks** The [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) is used in OPC UA to refer to existing types when for example declaring fields. ## Methods ### GetArrayRank virtual Gets the number of dimensions in an array.

```csharp public virtual int GetArrayRank() ```

```vbnet Public Overridable Function GetArrayRank() As Integer ```

**Returns** [Int32](https://learn.microsoft.com/dotnet/api/system.int32) An integer that contains the number of dimensions in the current type. **Exceptions** | Exception | Condition | |---|---| | [ArgumentException](https://learn.microsoft.com/dotnet/api/system.argumentexception) | The current type is not an array. | **Implements** [GetArrayRank](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.iopcdatatypeinfo/members#getarrayrank) ### GetElementType virtual Returns the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) of the object encompassed or referred to by the current array.

```csharp public virtual OpcDataTypeInfo GetElementType() ```

```vbnet Public Overridable Function GetElementType() As OpcDataTypeInfo ```

**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/) of the object encompassed or referred to by the current array or null if the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) is not an array. ### GetField Searches for the field with the specified `name`.

```csharp public OpcDataFieldInfo GetField(string name) ```

```vbnet Public Function GetField(name As String) As OpcDataFieldInfo ```

**Parameters** | Name | Type | Description | |---|---|---| | `name` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The [string](https://learn.microsoft.com/dotnet/api/system.string) containing the name of the data field to get. | **Returns** [OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/) An instance of the [OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/) representing the field with the specified name, if found; 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). | **Remarks** The `name` specified is compared using [Ordinal](https://learn.microsoft.com/dotnet/api/system.stringcomparison#system-stringcomparison-ordinal). ### GetFields Returns all the fields of the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/).

```csharp public OpcDataFieldInfo[] GetFields() ```

```vbnet Public Function GetFields() As OpcDataFieldInfo() ```

**Returns** [OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/)[] An array of [OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/) objects representing all the fields defined for the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) or an empty array of type [OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/) if no fields are defined for the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). ### GetFieldsCore protected · virtual When overriden in a derived class, searches for the fields defined for the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/).

```csharp protected virtual IEnumerable GetFieldsCore() ```

```vbnet Protected Overridable Function GetFieldsCore() As IEnumerable(Of OpcDataFieldInfo) ```

**Returns** [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)<[OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/)> A sequence of [OpcDataFieldInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatafieldinfo/) objects representing all fields defined for the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). ### GetUnderlyingType protected · virtual Retrieves the [Type](https://learn.microsoft.com/dotnet/api/system.type) which provides the implementation of the [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/).

```csharp protected virtual Type GetUnderlyingType() ```

```vbnet Protected Overridable Function GetUnderlyingType() As Type ```

**Returns** [Type](https://learn.microsoft.com/dotnet/api/system.type) The [Type](https://learn.microsoft.com/dotnet/api/system.type) which implements the type declared or a null reference (Nothing in Visual Basic) if there does not exist a declaration of the type described by this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). **Remarks** To determine the underlying [Type](https://learn.microsoft.com/dotnet/api/system.type) this method queries the [Type](https://learn.microsoft.com/dotnet/api/system.type) using the [TypeResolve](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdata/members#typeresolve) event. If there is no [Type](https://learn.microsoft.com/dotnet/api/system.type) information provided the method queries the types defined by the foundation stack using the [TypeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#typeid) and [Encoding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#encoding) of this [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). If there is still no [Type](https://learn.microsoft.com/dotnet/api/system.type) determined the method tries to resolve the [Type](https://learn.microsoft.com/dotnet/api/system.type) using the [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#name) to construct type names of types defined in the 'Opc.Ua' and 'System' namespace. ### GetXmlName static · 3 overloads | Overload | Description | |---|---| | [GetXmlName(string, string)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#getxmlname-system-string-system-string)static | Retrieves the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) for the `name` and `xmlNamespace` specified. | | [GetXmlName(string, OpcNamespace)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#getxmlname-system-string-opc-uafx-opcnamespace)static | Retrieves the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) for the `name` and `namespace` specified. | | [GetXmlName(string, OpcDataTypeDictionary)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#getxmlname-system-string-opc-uafx-opcdatatypedictionary)static | Retrieves the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) for the `name` and `typeDictionary` specified. | #### GetXmlName(string, string) static Retrieves the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) for the `name` and `xmlNamespace` specified.

```csharp public static XmlQualifiedName GetXmlName(string name, string xmlNamespace) ```

```vbnet Public Shared Function GetXmlName( name As String, xmlNamespace As String) As XmlQualifiedName ```

```csharp public static XmlQualifiedName GetXmlName(string name, OpcNamespace @namespace) ```

```vbnet Public Shared Function GetXmlName( name As String, [namespace] As OpcNamespace) As XmlQualifiedName ```

```csharp public static XmlQualifiedName GetXmlName( string name, OpcDataTypeDictionary typeDictionary) ```

```vbnet Public Shared Function GetXmlName( name As String, typeDictionary As OpcDataTypeDictionary) As XmlQualifiedName ```

**Parameters** | Name | Type | Description | |---|---|---| | `name` | [String](https://learn.microsoft.com/dotnet/api/system.string) | The name of the entity for which the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) is to be created. The value is used for the [Name](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname.name). | | `typeDictionary` | [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/) its [XmlNamespace](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypedictionary/members#xmlnamespace) is used to define the [Namespace](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname.namespace) to retrieve. This can be a null reference (Nothing in Visual Basic) as well. | **Returns** [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) A new instance of the [XmlQualifiedName](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname) which uses the `name` for the [Name](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname.name) and the `typeDictionary` (if specified) for the [Namespace](https://learn.microsoft.com/dotnet/api/system.xml.xmlqualifiedname.namespace). ### MakeArrayType 2 overloads | Overload | Description | |---|---| | [MakeArrayType()](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#makearraytype-noparams) | Returns a [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object representing a one-dimensional array of the current type, with a lower bound of zero. | | [MakeArrayType(int)](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#makearraytype-system-int32) | Returns a [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object representing an array of the current type, with the specified number of dimensions. | #### MakeArrayType() Returns a [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object representing a one-dimensional array of the current type, with a lower bound of zero.

```csharp public OpcDataTypeInfo MakeArrayType() ```

```vbnet Public Function MakeArrayType() As OpcDataTypeInfo ```

**Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) A [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object representing a one-dimensional array of the current type, with a lower bound of zero. #### MakeArrayType(int) Returns a [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) object representing an array of the current type, with the specified number of dimensions.

```csharp public OpcDataTypeInfo MakeArrayType(int rank) ```

```vbnet Public Function MakeArrayType(rank As Integer) As OpcDataTypeInfo ```

**Parameters** | Name | Type | Description | |---|---|---| | `rank` | [Int32](https://learn.microsoft.com/dotnet/api/system.int32) | The number of dimensions for the array. This number must be less than or equal to 32. | **Returns** [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/) An object representing an array of the current type, with the specified number of dimensions. **Exceptions** | Exception | Condition | |---|---| | [ArgumentOutOfRangeException](https://learn.microsoft.com/dotnet/api/system.argumentoutofrangeexception) | The `rank` is not between 1 and 32 (inclusive). | ### 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.opcdatatypeinfo/members#name) or the [UnderlyingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#underlyingtype) of the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/).

```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.opcdatatypeinfo/members#name) or the [UnderlyingType](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/members#underlyingtype) of the current [OpcDataTypeInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatatypeinfo/). **Overrides** [ToString()](https://learn.microsoft.com/dotnet/api/system.object.tostring)