OPC Studio User's Guide and Reference
IEasyDAClientExtension2 Class
Members  Example 



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.DataAccess.Extensions Namespace : IEasyDAClientExtension2 Class
Contains extension methods to the OpcLabs.EasyOpc.DataAccess.IEasyDAClient interface.
Syntax
'Declaration
 
<ExtensionAttribute()>
<ExceptionContractAnnotationAttribute(True)>
<ExceptionContractVerificationAttribute(True)>
<ComVisibleAttribute(False)>
Public MustInherit NotInheritable Class IEasyDAClientExtension2 
'Usage
 
Dim instance As IEasyDAClientExtension2
[Extension()]
[ExceptionContractAnnotation(true)]
[ExceptionContractVerification(true)]
[ComVisible(false)]
public static class IEasyDAClientExtension2 
[Extension()]
[ExceptionContractAnnotation(true)]
[ExceptionContractVerification(true)]
[ComVisible(false)]
public ref class IEasyDAClientExtension2 abstract sealed 
Remarks
Note that other extension classes for the OpcLabs.EasyOpc.DataAccess.IEasyDAClient exist as well. Specifically, the basic set of extension methods is in the OpcLabs.EasyOpc.DataAccess.IEasyDAClientExtension class.

This class contains extension methods (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

 

This chapter describes EasyOPC.NET extensions for OPC Data Access and OPC XML-DA.

 

Example
// This example shows how to obtain a data type of an OPC item.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.BaseLib.ComInterop;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.Extensions;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClientExtension
{
    class GetDataTypePropertyValue
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            // Get the DataType property value, already converted to VarType
            VarType varType;
            try
            {
                varType = client.GetDataTypePropertyValue("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display the obtained data type
            Console.WriteLine("VarType: {0}", varType); // Display data type symbolically
        }
    }
}
' This example shows how to obtain a data type of an OPC item.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.BaseLib.ComInterop
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.Extensions
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess._EasyDAClientExtension
    Friend Class GetDataTypePropertyValue
        Public Shared Sub Main1()
            Dim client = New EasyDAClient()

            ' Get the DataType property value, already converted to VarType
            Dim varType As VarType
            Try
                varType = client.GetDataTypePropertyValue("", "OPCLabs.KitServer.2", "Simulation.Random")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            ' Display the obtained data type
            Console.WriteLine("VarType: {0}", varType) ' Display data type symbolically
        End Sub
    End Class
End Namespace
# This example shows how to obtain a data type of an OPC item.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.BaseLib.ComInterop import *
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.DataAccess.Extensions import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Get the DataType property value, already converted to VarType.
try:
    varType = IEasyDAClientExtension2.GetDataTypePropertyValue(client, '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display the obtained data type.
print('VarType: ', varType, sep='')     # Display data type symbolically

print('Finished.')
// This example shows how to obtain a structure containing property values for an OPC item, and display some property values.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.Extensions;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClientExtension
{
    class GetItemPropertyRecord
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            // Get a structure containing values of all well-known properties
            DAItemPropertyRecord itemPropertyRecord;
            try
            {
                itemPropertyRecord = client.GetItemPropertyRecord("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display some of the obtained property values
            Console.WriteLine("itemPropertyRecord.AccessRights: {0}", itemPropertyRecord.AccessRights);
            Console.WriteLine("itemPropertyRecord.DataType: {0}", itemPropertyRecord.DataType);
            Console.WriteLine("itemPropertyRecord.Timestamp: {0}", itemPropertyRecord.Timestamp);
        }
    }
}
' This example shows how to obtain a structure containing property values for an OPC item, and display some property values.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.Extensions
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess._EasyDAClientExtension
    Friend Class GetItemPropertyRecord
        Public Shared Sub Main1()
            Dim client = New EasyDAClient()

            ' Get a structure containing values of all well-known properties
            Dim itemPropertyRecord As DAItemPropertyRecord
            Try
                itemPropertyRecord = client.GetItemPropertyRecord("", "OPCLabs.KitServer.2", "Simulation.Random")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            ' Display some of the obtained property values
            Console.WriteLine("itemPropertyRecord.AccessRights: {0}", itemPropertyRecord.AccessRights)
            Console.WriteLine("itemPropertyRecord.DataType: {0}", itemPropertyRecord.DataType)
            Console.WriteLine("itemPropertyRecord.Timestamp: {0}", itemPropertyRecord.Timestamp)
        End Sub
    End Class
End Namespace
# This example shows how to obtain a structure containing property values for an OPC item, and display some property
# values.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.DataAccess.Extensions import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Get a structure containing values of all well-known properties.
try:
    itemPropertyRecord = IEasyDAClientExtension2.GetItemPropertyRecord(client,
                                                                       '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display some of the obtained property values.
print('itemPropertyRecord.AccessRights: ', itemPropertyRecord.AccessRights, sep='')
print('itemPropertyRecord.DataType: ', itemPropertyRecord.DataType, sep='')
print('itemPropertyRecord.Timestamp: ', itemPropertyRecord.Timestamp, sep='')

print('Finished.')
// This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.Extensions;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClientExtension
{
    class GetPropertyValueDictionary
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            // Get dictionary of property values, for all well-known properties
            DAPropertyValueDictionary propertyValueDictionary;
            try
            {
                propertyValueDictionary = client.GetPropertyValueDictionary("", "OPCLabs.KitServer.2", "Simulation.Random");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            // Display some of the obtained property values
            // The production code should also check for the .Exception first, before getting .Value
            Console.WriteLine("propertyValueDictionary[DAPropertyId.AccessRights].Value: {0}",
                propertyValueDictionary[DAPropertyIds.AccessRights].Value);
            Console.WriteLine("propertyValueDictionary[DAPropertyId.DataType].Value: {0}",
                propertyValueDictionary[DAPropertyIds.DataType].Value);
            Console.WriteLine("propertyValueDictionary[DAPropertyId.Timestamp].Value: {0}",
                propertyValueDictionary[DAPropertyIds.Timestamp].Value);
        }
    }
}
' This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.Extensions
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess._EasyDAClientExtension
    Friend Class GetPropertyValueDictionary
        Public Shared Sub Main1()
            Dim client = New EasyDAClient()

            ' Get dictionary of property values, for all well-known properties
            Dim propertyValueDictionary As DAPropertyValueDictionary
            Try
                propertyValueDictionary = client.GetPropertyValueDictionary("", "OPCLabs.KitServer.2", "Simulation.Random")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            ' Display some of the obtained property values
            ' The production code should also check for the .Exception first, before getting .Value
            Console.WriteLine("propertyValueDictionary[DAPropertyId.AccessRights].Value: {0}", propertyValueDictionary(DAPropertyIds.AccessRights).Value)
            Console.WriteLine("propertyValueDictionary[DAPropertyId.DataType].Value: {0}", propertyValueDictionary(DAPropertyIds.DataType).Value)
            Console.WriteLine("propertyValueDictionary[DAPropertyId.Timestamp].Value: {0}", propertyValueDictionary(DAPropertyIds.Timestamp).Value)
        End Sub
    End Class
End Namespace
# This example shows how to obtain a dictionary of OPC property values for an OPC item, and extract property values.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.DataAccess.Extensions import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Get dictionary of property values, for all well-known properties.
try:
    propertyValueDictionary = IEasyDAClientExtension2.GetPropertyValueDictionary(client,
        '', 'OPCLabs.KitServer.2', 'Simulation.Random')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display some of the obtained property values.
# The production code should also check for the .Exception first, before getting .Value
print('propertyValueDictionary[DAPropertyId.AccessRights].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.AccessRights)).Value, sep='')
print('propertyValueDictionary[DAPropertyId.DataType].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.DataType)).Value, sep='')
print('propertyValueDictionary[DAPropertyId.Timestamp].Value: ',
    propertyValueDictionary.get_Item(DAPropertyId(DAPropertyIds.Timestamp)).Value, sep='')

print('Finished.')
Inheritance Hierarchy

System.Object
   OpcLabs.EasyOpc.DataAccess.Extensions.IEasyDAClientExtension2

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