QuickOPC User's Guide and Reference
DataTypeKind Property (_OpaqueData)
Example 



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.DataTypeModel.ComTypes Namespace > _OpaqueData Interface : DataTypeKind Property
The kind of this data.
Syntax
'Declaration
 
ReadOnly Property DataTypeKind As DataTypeKind
'Usage
 
Dim instance As _OpaqueData
Dim value As DataTypeKind
 
value = instance.DataTypeKind
DataTypeKind DataTypeKind {get;}
property DataTypeKind DataTypeKind {
   DataTypeKind get();
}
Remarks

The data type kinds correspond to classes derived from DataType. The following picture shows the class hierarchy:

.

This method or property does not throw any exceptions, aside from execution exceptions such as System.Threading.ThreadAbortException or System.OutOfMemoryException.

Example

.NET

COM

// Shows how to process generic data type, displaying some of its properties, recursively.

using System;
using System.Collections.Generic;
using OpcLabs.BaseLib.DataTypeModel;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.ComplexData;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.ComplexData._GenericData
{
    class DataTypeKind1
    {
        public static void Main1()
        {
            // Define which server and node we will work with.
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"
            UANodeDescriptor nodeDescriptor =
                "nsu=http://test.org/UA/Data/ ;i=10239"; // [ObjectsFolder]/Data.Static.Scalar.StructureValue

            // Instantiate the client object.
            var client = new EasyUAClient();

            // Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.
            UAGenericObject genericObject;
            try
            {
                genericObject = (UAGenericObject)client.ReadValue(endpointDescriptor, nodeDescriptor);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Process the generic data type. We will inspect some of its properties, and dump them.
            ProcessGenericData(genericObject.GenericData, maximumDepth: 3);
        }
        

        // Process the generic data type. Its structure can sometimes be quite deep, therefore we are limiting the depth
        // of the recursion using maximumDepth.
        public static void ProcessGenericData(GenericData genericData, int maximumDepth)
        {
            if (maximumDepth == 0)
                return;

            Console.WriteLine();
            Console.WriteLine("genericData.DataType: {0}", genericData.DataType);

            switch (genericData.DataTypeKind)
            {
                case DataTypeKind.Enumeration:
                    Console.WriteLine("The generic data is an enumeration.");
                    var enumerationData = (EnumerationData) genericData;
                    Console.WriteLine("Its value is {0}.", enumerationData.Value);
                    // There is also a ValueName that you can inspect (if known).
                    break;

                case DataTypeKind.Opaque:
                    Console.WriteLine("The generic data is opaque.");
                    var opaqueData = (OpaqueData) genericData;
                    Console.WriteLine("Its size is {0} bits.", opaqueData.SizeInBits);
                    Console.WriteLine("The data bytes are {0}.", BitConverter.ToString(opaqueData.ByteArray));
                    // Use the Value property (a BitArray) if you need to access the value bit by bit.
                    break;

                case DataTypeKind.Primitive:
                    Console.WriteLine("The generic data is primitive.");
                    var primitiveData = (PrimitiveData) genericData;
                    Console.WriteLine("Its value is \"{0}\".", primitiveData.Value);
                    break;

                case DataTypeKind.Sequence:
                    Console.WriteLine("The generic data is a sequence.");
                    var sequenceData = (SequenceData) genericData;
                    Console.WriteLine("It has {0} elements.", sequenceData.Elements.Count);
                    Console.WriteLine("A dump of the elements follows.");
                    foreach (GenericData element in sequenceData.Elements)
                        ProcessGenericData(element, maximumDepth - 1);
                    break;

                case DataTypeKind.Structured:
                    Console.WriteLine("The generic data is structured.");
                    var structuredData = (StructuredData) genericData;
                    Console.WriteLine("It has {0} field data members.", structuredData.FieldData.Count);
                    Console.WriteLine("The names of the fields are: {0}.",
                        String.Join(", ", structuredData.FieldData.Keys));

                    Console.WriteLine("A dump of each of the fields follows.");
                    foreach (KeyValuePair<string, GenericData> pair in structuredData.FieldData)
                    {
                        Console.WriteLine();
                        Console.WriteLine("Field name: {0}", pair.Key);
                        ProcessGenericData(pair.Value, maximumDepth - 1);
                    }
                    break;

                case DataTypeKind.Union:
                    Console.WriteLine("The generic data is a union.");
                    var unionData = (UnionData)genericData;
                    Console.WriteLine("The name of current field is: {0}", unionData.FieldName);
                    Console.WriteLine("Current field value is: {0}", unionData.FieldValue);
                    break;
            }
        }
    }
}
# Shows how to process generic data type, displaying some of its properties, recursively.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from OpcLabs.BaseLib.DataTypeModel import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


def processGenericData(genericData, maximumDepth):
    if maximumDepth == 0:
        print('* Reached maximum depth *')
        return

    print()
    print('genericData.DataType: ', genericData.DataType, sep='')

    dataTypeKind = genericData.DataTypeKind
    if dataTypeKind == DataTypeKind.Enumeration:
        print('The generic data is an enumeration.')
        enumerationData = genericData
        print('Its value is ', enumerationData.Value, '.', sep='')
        # There is also a ValueName that you can inspect (if known).

    elif dataTypeKind == DataTypeKind.Opaque:
        print('The generic data is opaque.')
        opaqueData = genericData
        print('Its size is ', opaqueData.SizeInBits, ' bits.', sep='')
        print('The data bytes are ', BitConverter.ToString(opaqueData.ByteArray), '.', sep='')
        # Use the Value property (a BitArray) if you need to access the value bit by bit.

    elif dataTypeKind == DataTypeKind.Primitive:
        print('The generic data is primitive.')
        primitiveData = genericData
        print('Its value is "', primitiveData.Value, '".', sep='')

    elif dataTypeKind == DataTypeKind.Sequence:
        print('The generic data is a sequence.')
        sequenceData = genericData
        print('It has ', sequenceData.Elements.Count, ' elements.', sep='')
        print('A dump of the elements follows.')
        for element in sequenceData.Elements:
            processGenericData(element, maximumDepth - 1)

    elif dataTypeKind == DataTypeKind.Structured:
        print('The generic data is structured.')
        structuredData = genericData
        print('It has ', structuredData.FieldData.Count, ' field data members.', sep='')
        print('The names of the fields are: ', end='')
        for i, name in enumerate(structuredData.FieldData.Keys):
            if i != 0:
                print(', ', end='')
            print(name, end='')
        print('.')

        print('A dump of each of the fields follows.')
        for pair in structuredData.FieldData:
            print()
            print('Field name: ', pair.Key, sep='')
            processGenericData(pair.Value, maximumDepth - 1)

    elif dataTypeKind == DataTypeKind.Union:
        print('The generic data is a union.')
        unionData = genericData
        print('The name of current field is: ', unionData.FieldName, sep='')
        print('Current field value is: ', unionData.FieldValue, end='')


# Define which server and node we will work with.
endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'

# [ObjectsFolder]/Data.Static.Scalar.StructureValue
nodeDescriptor = UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10239')

# Instantiate the client object.
client = EasyUAClient()

# Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.
try:
    print('Reading...')
    genericObject = IEasyUAClientExtension.ReadValue(client, endpointDescriptor, nodeDescriptor)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()
print('Reading successful.')

# Process the generic data type. We will inspect some of its properties, and dump them.
processGenericData(genericObject.GenericData, 3)

print()
print('Finished.')
' Shows how to process generic data type, displaying some of its properties, recursively.

Imports OpcLabs.BaseLib.DataTypeModel
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.ComplexData
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace ComplexData._GenericData

    Friend Class DataTypeKind1

        Public Shared Sub Main1()

            ' Define which server we will work with.
            Dim endpointDescriptor As UAEndpointDescriptor =
                    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
            ' or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            ' or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            ' Define which node we will work with.
            Dim nodeDescriptor As UANodeDescriptor = _
                "nsu=http://test.org/UA/Data/ ;i=10239"  ' [ObjectsFolder]/Data.Static.Scalar.StructureValue

            ' Instantiate the client object.
            Dim client = New EasyUAClient

            ' Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.
            Dim genericObject As UAGenericObject
            Try
                genericObject = CType(client.ReadValue(endpointDescriptor, nodeDescriptor), UAGenericObject)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Process the generic data type. We will inspect some of its properties, and dump them.
            ProcessGenericData(genericObject.GenericData, maximumDepth:=2)
        End Sub


        ' Process the generic data type. Its structure can sometimes be quite deep, therefore we are limiting the depth
        ' of the recursion using maximumDepth.
        Public Shared Sub ProcessGenericData(ByVal genericData As GenericData, ByVal maximumDepth As Integer)
            If (maximumDepth = 0) Then
                Return
            End If

            Console.WriteLine()
            Console.WriteLine("genericData.DataType: {0}", genericData.DataType)

            Select Case (genericData.DataTypeKind)
                Case DataTypeKind.Enumeration
                    Console.WriteLine("The generic data is an enumeration.")
                    Dim enumerationData = CType(genericData, EnumerationData)
                    Console.WriteLine("Its value is {0}.", enumerationData.Value)
                    ' There is also a ValueName that you can inspect (if known).

                Case DataTypeKind.Opaque
                    Console.WriteLine("The generic data is opaque.")
                    Dim opaqueData = CType(genericData, OpaqueData)
                    Console.WriteLine("Its size is {0} bits.", opaqueData.SizeInBits)
                    Console.WriteLine("The data bytes are {0}.", BitConverter.ToString(opaqueData.ByteArray))
                    ' Use the Value property (a BitArray) if you need to access the value bit by bit.

                Case DataTypeKind.Primitive
                    Console.WriteLine("The generic data is primitive.")
                    Dim primitiveData = CType(genericData, PrimitiveData)
                    Console.WriteLine("Its value is ""{0}"".", primitiveData.Value)

                Case DataTypeKind.Sequence
                    Console.WriteLine("The generic data is a sequence.")
                    Dim sequenceData = CType(genericData, SequenceData)
                    Console.WriteLine("It has {0} elements.", sequenceData.Elements.Count)
                    Console.WriteLine("A dump of the elements follows.")
                    For Each element As GenericData In sequenceData.Elements
                        ProcessGenericData(element, (maximumDepth - 1))
                    Next

                Case DataTypeKind.Structured
                    Console.WriteLine("The generic data is structured.")
                    Dim structuredData = CType(genericData, StructuredData)
                    Console.WriteLine("It has {0} field data members.", structuredData.FieldData.Count)
                    Console.WriteLine("The names of the fields are: {0}.", String.Join(", ", structuredData.FieldData.Keys))

                    Console.WriteLine("A dump of each of the fields follows.")
                    For Each pair As KeyValuePair(Of String, GenericData) In structuredData.FieldData
                        Console.WriteLine()
                        Console.WriteLine("Field name: {0}", pair.Key)
                        ProcessGenericData(pair.Value, (maximumDepth - 1))
                    Next

                Case DataTypeKind.Union
                    Console.WriteLine("The generic data is union.")
                    Dim unionData = CType(genericData, UnionData)
                    Console.WriteLine("The name of current field is: {0}", unionData.FieldName)
                    Console.WriteLine("Current field value is: {0}", unionData.FieldValue)
            End Select

        End Sub
    End Class
End Namespace
// Shows how to process generic data type, displaying some of its properties, recursively

class procedure DataTypeKind1.Main;
var
  Client: _EasyUAClient;
  EndpointDescriptor: string;
  GenericObject: _UAGenericObject;
  NodeDescriptor: string;
begin
  EndpointDescriptor := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  NodeDescriptor := 'nsu=http://test.org/UA/Data/ ;i=10239';  // [ObjectsFolder]/Data.Static.Scalar.StructureValue

  // Instantiate the client object
  Client := CoEasyUAClient.Create;

  // Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.

  try
    GenericObject := _UAGenericObject(IUnknown(Client.ReadValue(EndpointDescriptor, NodeDescriptor)));
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
      Exit;
    end;
  end;

  // Process the generic data type. We will inspect some of its properties, and dump them.
  ProcessGenericData(GenericObject.GenericData, 2);
end;

Function VariantToBytes(Const Value: OleVariant): TBytes;
Var
  Size: Integer;
  pData: Pointer;
Begin
  Size := Succ(VarArrayHighBound(Value, 1) - VarArrayLowBound(Value, 1));
  SetLength(Result, Size);
  pData := VarArrayLock(Value);
  Try
    Move(pData^, Pointer(Result)^, Size);
  Finally
    VarArrayUnlock(Value);
  End;
End;

class procedure DatatypeKind1.ProcessGenericData(GenericData: OpcLabs_BaseLib_TLB._GenericData; MaximumDepth: Cardinal);
var
  ByteArray: OleVariant;
  Count: Cardinal;
  Element: OleVariant;
  ElementEnumerator: IEnumVARIANT;
  EnumerationData: _EnumerationData;
  First: boolean;
  Keys: string;
  OpaqueData: _OpaqueData;
  PrimitiveData: _PrimitiveData;
  SequenceData: _SequenceData;
  StructuredData: _StructuredData;
  Value: OpcLabs_BaseLib_TLB._GenericData;
begin
  if MaximumDepth = 0 then
    Exit;

  WriteLn;
  WriteLn('genericData.DataType: ', GenericData.DataType.ToString);

  case GenericData.DataTypeKind of
    DataTypeKind_Enumeration:
      begin
        WriteLn('The generic data is an enumeration.');
        EnumerationData := GenericData as _EnumerationData;
        WriteLn(Format('Its value is %s.', [EnumerationData.Value.ToString]));
        // There is also a ValueName that you can inspect (if known).
      end;
    DataTypeKind_Opaque:
      begin
        WriteLn('The generic data is opaque.');
        OpaqueData := GenericData as _OpaqueData;
        WriteLn(Format('Its size is %d bits.', [OpaqueData.SizeInBits]));
        TVarData(ByteArray).VType := varArray;
        TVarData(ByteArray).VArray := PVarArray(OpaqueData.ByteArray);
        WriteLn(Format('The data bytes are %s.', [TEncoding.ANSI.GetString(VariantToBytes(ByteArray))]));
        // Use the Value property (a BitArray) if you need to access the value bit by bit.
      end;
    DataTypeKind_Primitive:
      begin
        WriteLn('The generic data is primitive.');
        PrimitiveData := GenericData as _PrimitiveData;
        WriteLn(Format('Its value is "%s".', [PrimitiveData.Value]));
      end;
    DataTypeKind_Sequence:
      begin
        WriteLn('The generic data is a sequence.');
        SequenceData := GenericData as _SequenceData;
        WriteLn(Format('It has %s elements.', [SequenceData.Elements.Count.ToString]));
        WriteLn('A dump of the elements follows.');
        ElementEnumerator := SequenceData.Elements.GetEnumerator;
        while (ElementEnumerator.Next(1, Element, Count) = S_OK) do
        begin
          ProcessGenericData(IUnknown(Element) as OpcLabs_BaseLib_TLB._GenericData, MaximumDepth - 1);
        end;
      end;
    DataTypeKind_Structured:
      begin
        WriteLn('The generic data is structured.');
        StructuredData := GenericData as _StructuredData;
        WriteLn(Format('It has %s field data members.', [StructuredData.FieldData.Count.ToString]));
        ElementEnumerator := StructuredData.FieldData.GetEnumerator;
        Keys := '';
        First := True;
        while (ElementEnumerator.Next(1, Element, Count) = S_OK) do
        begin
          if First then
            First := False
          else
            Keys := Keys + ', ';
          Keys := Keys + Element.Key;
        end;
        WriteLn(Format('The names of the fields are: %s.', [Keys]));

        WriteLn('A dump of each of the fields follows.');
        ElementEnumerator := StructuredData.FieldData.GetEnumerator;
        while (ElementEnumerator.Next(1, Element, Count) = S_OK) do
        begin
          WriteLn;
          WriteLn(Format('Field name: %s', [Element.Key]));
          Value := IUnknown(Element.Value) as OpcLabs_BaseLib_TLB._GenericData;
          ProcessGenericData(Value, MaximumDepth - 1);
        end;
      end;
  end;

end;

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also