QuickOPC User's Guide and Reference
ValueResult Class
Members  Example 



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.OperationModel Namespace : ValueResult Class
Holds result of an operation in form of a generic System.Object value.
Object Model
ValueResult ClassExceptionCollection ClassNormalizedExceptionCollection ClassNormalizedException ClassNormalizedException Class
Syntax
'Declaration
 
<CLSCompliantAttribute(True)>
<ComDefaultInterfaceAttribute(OpcLabs.BaseLib.OperationModel.ComTypes._ValueResult)>
<ComVisibleAttribute(True)>
<GuidAttribute("B7F6D964-ABA2-4E36-9D96-0E3096F615D7")>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<ValueControlAttribute("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.72.465.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=False, 
   Export=True, 
   PageId=10001)>
<SerializableAttribute()>
Public Class ValueResult 
   Inherits OperationResult
   Implements OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.BaseLib.OperationModel.ComTypes._OperationResult, OpcLabs.BaseLib.OperationModel.ComTypes._ValueResult, System.Collections.IStructuralEquatable, System.ICloneable, System.IFormattable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
'Usage
 
Dim instance As ValueResult
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.BaseLib.OperationModel.ComTypes._ValueResult)]
[ComVisible(true)]
[Guid("B7F6D964-ABA2-4E36-9D96-0E3096F615D7")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[ValueControl("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.72.465.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=false, 
   Export=true, 
   PageId=10001)]
[Serializable()]
public class ValueResult : OperationResult, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.BaseLib.OperationModel.ComTypes._OperationResult, OpcLabs.BaseLib.OperationModel.ComTypes._ValueResult, System.Collections.IStructuralEquatable, System.ICloneable, System.IFormattable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.BaseLib.OperationModel.ComTypes._ValueResult)]
[ComVisible(true)]
[Guid("B7F6D964-ABA2-4E36-9D96-0E3096F615D7")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[ValueControl("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.72.465.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=false, 
   Export=true, 
   PageId=10001)]
[Serializable()]
public ref class ValueResult : public OperationResult, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.BaseLib.OperationModel.ComTypes._OperationResult, OpcLabs.BaseLib.OperationModel.ComTypes._ValueResult, System.Collections.IStructuralEquatable, System.ICloneable, System.IFormattable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
Remarks

The result is successful if the Exception is a null reference. Otherwise, this property contains information about the reason of the failure.

Example

.NET

// This example shows how to read the Value attributes of 3 different nodes at once. Using the same method, it is also possible 
// to read multiple attributes of the same node.

using System;
using OpcLabs.BaseLib.OperationModel;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class ReadMultipleValues
    {
        public static void Main1()
        {
            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/"

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

            // Obtain values. By default, the Value attributes of the nodes will be read.
            ValueResult[] valueResultArray = client.ReadMultipleValues(new[]
                {
                    new UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845"),
                    new UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853"),
                    new UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855")
                });

            // Display results.
            foreach (ValueResult valueResult in valueResultArray)
            {
                if (valueResult.Succeeded)
                    Console.WriteLine($"Value: {valueResult.Value}");
                else
                    Console.WriteLine($"*** Failure: {valueResult.ErrorMessageBrief}");
            }


            // Example output:
            //
            //Value: 8
            //Value: -8.06803E+21
            //Value: Strawberry Pig Banana Snake Mango Purple Grape Monkey Purple? Blueberry Lemon^            
        }
    }
}
# This example shows how to read the Value attributes of 3 different nodes at once. Using the same method, it is also possible
# to read multiple attributes of the same node.

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

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


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/'

# Instantiate the client object.
client = EasyUAClient()

# Obtain values. By default, the Value attributes of the nodes will be read.
valueResultArray = IEasyUAClientExtension.ReadMultipleValues(client, [
    UAReadArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10845')),
    UAReadArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853')),
    UAReadArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10855')),
    ])

# Display results.
for valueResult in valueResultArray:
    if valueResult.Succeeded:
        print('Value: ', valueResult.Value, sep='')
    else:
        print('*** Failure: ', valueResult.ErrorMessageBrief, sep='')

print()
print('Finished.')
# This example shows how to read the Value attributes of 3 different nodes at once. Using the same method, it is also possible 
# to read multiple attributes of the same node.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.OperationModel

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUA.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUAComponents.dll"

[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/"

# Instantiate the client object.
$client = New-Object EasyUAClient

# Obtain values. By default, the Value attributes of the nodes will be read.
$valueResultArray = $client.ReadMultipleValues([UAReadArguments[]]@(
        (New-Object UAReadArguments($endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845")), 
        (New-Object UAReadArguments($endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853")), 
        (New-Object UAReadArguments($endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855"))
    ))

foreach ($valueResult in $valueResultArray) {
    if ($valueResult.Succeeded) {
        Write-Host "Value: $($valueResult.Value)"
    }
    else {
        Write-Host "*** Failure: $($valueResult.ErrorMessageBrief)"
    }
}


# Example output:
#
#Value: 8
#Value: -8.06803E+21
#Value: Strawberry Pig Banana Snake Mango Purple Grape Monkey Purple? Blueberry Lemon^            
' This example shows how to read the Value attributes of 3 different nodes at once. Using the same method, it is also possible 
' to read multiple attributes of the same node.

Imports System
Imports OpcLabs.BaseLib.OperationModel
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Partial Friend Class ReadMultipleValues
        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/"

            ' Instantiate the client object
            Dim client = New EasyUAClient()

            ' Obtain values. By default, the Value attributes of the nodes will be read.
            Dim valueResultArray() As ValueResult = client.ReadMultipleValues(New UAReadArguments() _
               {
                   New UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845"),
                   New UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853"),
                   New UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855")
               }
            )

            ' Display results
            For Each valueResult As ValueResult In valueResultArray
                If valueResult.Succeeded Then
                    Console.WriteLine("Value: {0}", valueResult.Value)
                Else
                    Console.WriteLine("*** Failure: {0}", valueResult.ErrorMessageBrief)
                End If
            Next valueResult

            ' Example output:
            '
            'Value: 8
            'Value: -8.06803E+21
            'Value: Strawberry Pig Banana Snake Mango Purple Grape Monkey Purple? Blueberry Lemon^            
        End Sub
    End Class
End Namespace
Inheritance Hierarchy

System.Object
   OpcLabs.BaseLib.Object2
      OpcLabs.BaseLib.Info
         OpcLabs.BaseLib.OperationModel.OperationResult
            OpcLabs.BaseLib.OperationModel.ValueResult
               OpcLabs.BaseLib.OperationModel.Generic.ValueResult<T>

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