BrowseLeaves(IEasyDAClient,ServerDescriptor,DANodeDescriptor,String) Method

Browses the specified branch (or root) in OPC server's address space, and returns information about child leaves found. Browse for child leaves. Specify server descriptor, and element name filter.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function BrowseLeaves( _
   ByVal client As IEasyDAClient, _
   ByVal serverDescriptor As ServerDescriptor, _
   ByVal parentNodeDescriptor As DANodeDescriptor, _
   ByVal elementNameFilter As String _
) As DANodeElementCollection

'Usage
 
Dim client As IEasyDAClient
Dim serverDescriptor As ServerDescriptor
Dim parentNodeDescriptor As DANodeDescriptor
Dim elementNameFilter As String
Dim value As DANodeElementCollection
 
value = IEasyDAClientExtension.BrowseLeaves(client, serverDescriptor, parentNodeDescriptor, elementNameFilter)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static DANodeElementCollection BrowseLeaves( 
   IEasyDAClient client,
   ServerDescriptor serverDescriptor,
   DANodeDescriptor parentNodeDescriptor,
   string elementNameFilter
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static DANodeElementCollection^ BrowseLeaves( 
   IEasyDAClient^ client,
   ServerDescriptor^ serverDescriptor,
   DANodeDescriptor^ parentNodeDescriptor,
   String^ elementNameFilter
)

Parameters

client: The client object that will perform the operation.
serverDescriptor: The OPC server involved in the operation.
parentNodeDescriptor: Descriptor for the parent branch to be browsed (can be the root).
elementNameFilter: A wildcard string to filter the returned element names (empty string for no filtering)

Return Value

The method returns a keyed collection of OpcLabs.EasyOpc.DataAccess.AddressSpace.DANodeElement values, each containing information about a particular leaf found. The keys of the keyed collection are the names of the leaves.

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	A `null` reference (`Nothing` in Visual Basic) is passed to a method that does not accept it as a valid argument. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.
OpcLabs.EasyOpc.OperationModel.OpcException	The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause. This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

System.ArgumentNullException

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

OpcLabs.EasyOpc.OperationModel.OpcException

The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Example

.NET

COM

// This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it displays 
// the ItemID of the node.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

namespace DocExamples.DataAccess._EasyDAClient
{
    class BrowseLeaves
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();
            DANodeElementCollection leafElements;
            try
            {
                leafElements = client.BrowseLeaves("", "OPCLabs.KitServer.2", "Simulation");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (DANodeElement leafElement in leafElements)
                Console.WriteLine($"LeafElements(\"{leafElement.Name}\").ItemId: {leafElement.ItemId}");
        }


        // Example output:
        //
        //LeafElements("Register_ArrayOfI2").ItemId: Simulation.Register_ArrayOfI2
        //LeafElements("Register_ArrayOfI4").ItemId: Simulation.Register_ArrayOfI4
        //LeafElements("Staircase 0:2 (10 s)").ItemId: Simulation.Staircase 0:2 (10 s)
        //LeafElements("Constant_VARIANT").ItemId: Simulation.Constant_VARIANT
        //LeafElements("Staircase 0:10 (1 s)").ItemId: Simulation.Staircase 0:10 (1 s)
        //LeafElements("Register_DATE").ItemId: Simulation.Register_DATE
        //LeafElements("Constant_RECORD").ItemId: Simulation.Constant_RECORD
        //LeafElements("ReadValue_DECIMAL").ItemId: Simulation.ReadValue_DECIMAL
        //LeafElements("Ramp 0:360 (1 s)").ItemId: Simulation.Ramp 0:360 (1 s)
        //LeafElements("Constant_NULL").ItemId: Simulation.Constant_NULL
        //LeafElements("ReadValue_ArrayOfUI2").ItemId: Simulation.ReadValue_ArrayOfUI2
        //LeafElements("ReadValue_ArrayOfUI1").ItemId: Simulation.ReadValue_ArrayOfUI1
        //LeafElements("ReadValue_ArrayOfUI4").ItemId: Simulation.ReadValue_ArrayOfUI4
        //LeafElements("Constant_CY").ItemId: Simulation.Constant_CY
        //LeafElements("Staircase 0:2 (1 min)").ItemId: Simulation.Staircase 0:2 (1 min)
        //LeafElements("Staircase 0:2 (10 min)").ItemId: Simulation.Staircase 0:2 (10 min)
        //LeafElements("Square (10 s)").ItemId: Simulation.Square(10 s)
        //LeafElements("Register_ArrayOfBSTR").ItemId: Simulation.Register_ArrayOfBSTR
        //LeafElements("ReadValue_I2").ItemId: Simulation.ReadValue_I2
        //LeafElements("ReadValue_I1").ItemId: Simulation.ReadValue_I1
        //LeafElements("ReadValue_I4").ItemId: Simulation.ReadValue_I4
        //LeafElements("Ramp (1 s)").ItemId: Simulation.Ramp(1 s)
        //LeafElements("ReadValue_ArrayOfDATE").ItemId: Simulation.ReadValue_ArrayOfDATE
        //LeafElements("OnOff (1 s)").ItemId: Simulation.OnOff(1 s)
        //LeafElements("AlternatingQuality Uncertain (1 s)").ItemId: Simulation.AlternatingQuality Uncertain(1 s)
        //LeafElements("Register_NULL").ItemId: Simulation.Register_NULL
        //LeafElements("Random (1 min)").ItemId: Simulation.Random(1 min)
        //LeafElements("Random (10 min)").ItemId: Simulation.Random(10 min)
        //LeafElements("AlternatingError (10 s)").ItemId: Simulation.AlternatingError(10 s)
        //LeafElements("ReadValue_ArrayOfI1").ItemId: Simulation.ReadValue_ArrayOfI1
        //LeafElements("ReadValue_ArrayOfI2").ItemId: Simulation.ReadValue_ArrayOfI2
        //LeafElements("ReadValue_UI2").ItemId: Simulation.ReadValue_UI2
        //LeafElements("ReadValue_ArrayOfI4").ItemId: Simulation.ReadValue_ArrayOfI4
        //LeafElements("ReadValue_UI1").ItemId: Simulation.ReadValue_UI1
        //LeafElements("ReadValue_UI4").ItemId: Simulation.ReadValue_UI4
        //LeafElements("Weekdays (1 s)").ItemId: Simulation.Weekdays(1 s)
        //LeafElements("AlternatingQuality Uncertain (1 min)").ItemId: Simulation.AlternatingQuality Uncertain(1 min)
        //LeafElements("AlternatingQuality Uncertain (10 min)").ItemId: Simulation.AlternatingQuality Uncertain(10 min)
        //LeafElements("Weekdays (1 min)").ItemId: Simulation.Weekdays(1 min)
        //LeafElements("Weekdays (10 min)").ItemId: Simulation.Weekdays(10 min)
        //LeafElements("OnOff (10 s)").ItemId: Simulation.OnOff(10 s)
        //LeafElements("ReadWriteCount").ItemId: Simulation.ReadWriteCount
        //LeafElements("Register_UNKNOWN").ItemId: Simulation.Register_UNKNOWN
        //LeafElements("AlternatingQuality Uncertain (10 s)").ItemId: Simulation.AlternatingQuality Uncertain(10 s)
        //LeafElements("Constant_BSTR").ItemId: Simulation.Constant_BSTR
        //LeafElements("Constant_ERROR").ItemId: Simulation.Constant_ERROR
        //LeafElements("Constant_UI2").ItemId: Simulation.Constant_UI2
        //LeafElements("Constant_UI1").ItemId: Simulation.Constant_UI1
        //LeafElements("Constant_UI4").ItemId: Simulation.Constant_UI4
        //LeafElements("Constant_R4").ItemId: Simulation.Constant_R4
        //LeafElements("Constant_R8").ItemId: Simulation.Constant_R8
        //LeafElements("ReadValue_ArrayOfBSTR").ItemId: Simulation.ReadValue_ArrayOfBSTR
        //LeafElements("Register_ArrayOfR4").ItemId: Simulation.Register_ArrayOfR4
        //LeafElements("Register_ArrayOfR8").ItemId: Simulation.Register_ArrayOfR8
        //LeafElements("Ramp 0:360 (1 min)").ItemId: Simulation.Ramp 0:360 (1 min)
        //LeafElements("Ramp 0:360 (10 min)").ItemId: Simulation.Ramp 0:360 (10 min)
        //LeafElements("RegisterSet_n").ItemId: 
        //LeafElements("Register_ArrayOfUI4").ItemId: Simulation.Register_ArrayOfUI4
        //LeafElements("Register_ArrayOfUI1").ItemId: Simulation.Register_ArrayOfUI1
        //LeafElements("Register_ArrayOfUI2").ItemId: Simulation.Register_ArrayOfUI2
        //LeafElements("Register").ItemId: Simulation.Register
        //LeafElements("Constant_EMPTY").ItemId: Simulation.Constant_EMPTY
        //LeafElements("Register_RECORD").ItemId: Simulation.Register_RECORD
        //LeafElements("ReadValue_ArrayOfBOOL").ItemId: Simulation.ReadValue_ArrayOfBOOL
        //LeafElements("AlternatingError (1 min)").ItemId: Simulation.AlternatingError(1 min)
        //LeafElements("AlternatingError (10 min)").ItemId: Simulation.AlternatingError(10 min)
        //LeafElements("OnOff (1 min)").ItemId: Simulation.OnOff(1 min)
        //LeafElements("ReadValue_DATE").ItemId: Simulation.ReadValue_DATE
        //LeafElements("Register_ERROR").ItemId: Simulation.Register_ERROR
        //LeafElements("ReadValue_ArrayOfUINT").ItemId: Simulation.ReadValue_ArrayOfUINT
        //LeafElements("Incrementing (10 s)").ItemId: Simulation.Incrementing(10 s)
        //LeafElements("ReadValue_ArrayOfINT").ItemId: Simulation.ReadValue_ArrayOfINT
        //LeafElements("ReadValue_BOOL").ItemId: Simulation.ReadValue_BOOL
        //LeafElements("Register_ArrayOfCY").ItemId: Simulation.Register_ArrayOfCY
        //LeafElements("Incrementing (1 s)").ItemId: Simulation.Incrementing(1 s)
        //LeafElements("Constant_UINT").ItemId: Simulation.Constant_UINT
        //LeafElements("ReadValue_ArrayOfR4").ItemId: Simulation.ReadValue_ArrayOfR4
        //LeafElements("ReadValue_ArrayOfR8").ItemId: Simulation.ReadValue_ArrayOfR8
        //LeafElements("Constant_I4").ItemId: Simulation.Constant_I4
        //LeafElements("Constant_I2").ItemId: Simulation.Constant_I2
        //LeafElements("Constant_I1").ItemId: Simulation.Constant_I1
        //LeafElements("Register_BOOL").ItemId: Simulation.Register_BOOL
        //LeafElements("Constant_UNKNOWN").ItemId: Simulation.Constant_UNKNOWN
        //LeafElements("Ramp 0:100 (1 s)").ItemId: Simulation.Ramp 0:100 (1 s)
        //LeafElements("Register_UI4").ItemId: Simulation.Register_UI4
        //LeafElements("Register_UI2").ItemId: Simulation.Register_UI2
        //LeafElements("Register_UI1").ItemId: Simulation.Register_UI1
        //LeafElements("AlternatingError (1 s)").ItemId: Simulation.AlternatingError(1 s)
        //LeafElements("Sine (10 s)").ItemId: Simulation.Sine(10 s)
        //LeafElements("Constant_BOOL").ItemId: Simulation.Constant_BOOL
        //LeafElements("Sine -100:100 (10 s)").ItemId: Simulation.Sine -100:100 (10 s)
        //LeafElements("Register_UINT").ItemId: Simulation.Register_UINT
        //LeafElements("Constant").ItemId: Simulation.Constant
        //LeafElements("Sine (1 s)").ItemId: Simulation.Sine(1 s)
        //LeafElements("Register_I1").ItemId: Simulation.Register_I1
        //LeafElements("Register_I2").ItemId: Simulation.Register_I2
        //LeafElements("Register_I4").ItemId: Simulation.Register_I4
        //LeafElements("ReadValue_ArrayOfCY").ItemId: Simulation.ReadValue_ArrayOfCY
        //LeafElements("Register_ArrayOfUINT").ItemId: Simulation.Register_ArrayOfUINT
        //LeafElements("Incrementing (1 min)").ItemId: Simulation.Incrementing(1 min)
        //LeafElements("Weekdays (10 s)").ItemId: Simulation.Weekdays(10 s)
        //LeafElements("Square (1 s)").ItemId: Simulation.Square(1 s)
        //LeafElements("Sine (1 min)").ItemId: Simulation.Sine(1 min)
        //LeafElements("Sine (10 min)").ItemId: Simulation.Sine(10 min)
        //LeafElements("Constant_DISPATCH").ItemId: Simulation.Constant_DISPATCH
        //LeafElements("Ramp 0:100 (1 min)").ItemId: Simulation.Ramp 0:100 (1 min)
        //LeafElements("Ramp 0:100 (10 min)").ItemId: Simulation.Ramp 0:100 (10 min)
        //LeafElements("Random (1 s)").ItemId: Simulation.Random(1 s)
        //LeafElements("Staircase 0:10 (1 min)").ItemId: Simulation.Staircase 0:10 (1 min)
        //LeafElements("Staircase 0:10 (10 min)").ItemId: Simulation.Staircase 0:10 (10 min)
        //LeafElements("AlternatingQuality Bad (1 s)").ItemId: Simulation.AlternatingQuality Bad(1 s)
        //LeafElements("Sine -100:100 (1 s)").ItemId: Simulation.Sine -100:100 (1 s)
        //LeafElements("Register_ArrayOfDATE").ItemId: Simulation.Register_ArrayOfDATE
        //LeafElements("AlternatingQuality Bad (10 s)").ItemId: Simulation.AlternatingQuality Bad(10 s)
        //LeafElements("ReadValue_R4").ItemId: Simulation.ReadValue_R4
        //LeafElements("ReadValue_R8").ItemId: Simulation.ReadValue_R8
        //LeafElements("Ramp (1 min)").ItemId: Simulation.Ramp(1 min)
        //LeafElements("Ramp (10 min)").ItemId: Simulation.Ramp(10 min)
        //LeafElements("Register_DISPATCH").ItemId: Simulation.Register_DISPATCH
        //LeafElements("OnOff (10 min)").ItemId: Simulation.OnOff(10 min)
        //LeafElements("ReadValue_BSTR").ItemId: Simulation.ReadValue_BSTR
        //LeafElements("Staircase 0:10 (10 s)").ItemId: Simulation.Staircase 0:10 (10 s)
        //LeafElements("Random (10 s)").ItemId: Simulation.Random(10 s)
        //LeafElements("Incrementing").ItemId: Simulation.Incrementing
        //LeafElements("Register_BSTR").ItemId: Simulation.Register_BSTR
        //LeafElements("ReadValue_UINT").ItemId: Simulation.ReadValue_UINT
        //LeafElements("Register_CY").ItemId: Simulation.Register_CY
        //LeafElements("AlternatingQuality Bad (1 min)").ItemId: Simulation.AlternatingQuality Bad(1 min)
        //LeafElements("AlternatingQuality Bad (10 min)").ItemId: Simulation.AlternatingQuality Bad(10 min)
        //LeafElements("Random").ItemId: Simulation.Random
        //LeafElements("Sine -100:100 (1 min)").ItemId: Simulation.Sine -100:100 (1 min)
        //LeafElements("Sine -100:100 (10 min)").ItemId: Simulation.Sine -100:100 (10 min)
        //LeafElements("Ramp (10 s)").ItemId: Simulation.Ramp(10 s)
        //LeafElements("ReadValue_INT").ItemId: Simulation.ReadValue_INT
        //LeafElements("Staircase 0:2 (1 s)").ItemId: Simulation.Staircase 0:2 (1 s)
        //LeafElements("ReadValue_CY").ItemId: Simulation.ReadValue_CY
        //LeafElements("Register_R8").ItemId: Simulation.Register_R8
        //LeafElements("Register_R4").ItemId: Simulation.Register_R4
        //LeafElements("Register_DECIMAL").ItemId: Simulation.Register_DECIMAL
        //LeafElements("Incrementing (10 min)").ItemId: Simulation.Incrementing(10 min)
        //LeafElements("Register_EMPTY").ItemId: Simulation.Register_EMPTY
        //LeafElements("Constant_INT").ItemId: Simulation.Constant_INT
        //LeafElements("Register_INT").ItemId: Simulation.Register_INT
        //LeafElements("Register_ArrayOfBOOL").ItemId: Simulation.Register_ArrayOfBOOL
        //LeafElements("Ramp 0:100 (10 s)").ItemId: Simulation.Ramp 0:100 (10 s)
        //LeafElements("Ramp 0:360 (10 s)").ItemId: Simulation.Ramp 0:360 (10 s)
        //LeafElements("Square (1 min)").ItemId: Simulation.Square(1 min)
        //LeafElements("Square (10 min)").ItemId: Simulation.Square(10 min)
        //LeafElements("Constant_DECIMAL").ItemId: Simulation.Constant_DECIMAL
        //LeafElements("Register_VARIANT").ItemId: Simulation.Register_VARIANT
        //LeafElements("Constant_DATE").ItemId: Simulation.Constant_DATE
        //LeafElements("Register_ArrayOfINT").ItemId: Simulation.Register_ArrayOfINT
    }
}

# This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it
# displays the ItemID of the node.
#
# 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 .
# 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.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

# Perform the operation.
try:
    nodeElements = IEasyDAClientExtension.BrowseLeaves(client, '', 'OPCLabs.KitServer.2', 'Simulation')
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

# Display results.
for nodeElement in nodeElements:
    print('NodeElements["', nodeElement.Name, '"].ItemId: ', nodeElement.ItemId, sep='')

' This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it displays 
' the ItemID of the node.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.AddressSpace
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess._EasyDAClient
    Partial Friend Class BrowseLeaves
        Shared Sub Main1()
            Dim client = New EasyDAClient()

            Dim leafElements As DANodeElementCollection
            Try
                leafElements = client.BrowseLeaves("", "OPCLabs.KitServer.2", "Simulation")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            For Each leafElement In leafElements
                Console.WriteLine($"LeafElements(""{leafElement.Name}"").ItemId: {leafElement.ItemId}")
            Next leafElement

        End Sub

        ' Example output
        '
        'LeafElements("Register_ArrayOfI2").ItemId: Simulation.Register_ArrayOfI2
        'LeafElements("Register_ArrayOfI4").ItemId: Simulation.Register_ArrayOfI4
        'LeafElements("Staircase 0:2 (10 s)").ItemId: Simulation.Staircase 0:2 (10 s)
        'LeafElements("Constant_VARIANT").ItemId: Simulation.Constant_VARIANT
        'LeafElements("Staircase 0:10 (1 s)").ItemId: Simulation.Staircase 0:10 (1 s)
        'LeafElements("Register_DATE").ItemId: Simulation.Register_DATE
        'LeafElements("Constant_RECORD").ItemId: Simulation.Constant_RECORD
        'LeafElements("ReadValue_DECIMAL").ItemId: Simulation.ReadValue_DECIMAL
        'LeafElements("Ramp 0:360 (1 s)").ItemId: Simulation.Ramp 0:360 (1 s)
        'LeafElements("Constant_NULL").ItemId: Simulation.Constant_NULL
        'LeafElements("ReadValue_ArrayOfUI2").ItemId: Simulation.ReadValue_ArrayOfUI2
        'LeafElements("ReadValue_ArrayOfUI1").ItemId: Simulation.ReadValue_ArrayOfUI1
        'LeafElements("ReadValue_ArrayOfUI4").ItemId: Simulation.ReadValue_ArrayOfUI4
        'LeafElements("Constant_CY").ItemId: Simulation.Constant_CY
        'LeafElements("Staircase 0:2 (1 min)").ItemId: Simulation.Staircase 0:2 (1 min)
        'LeafElements("Staircase 0:2 (10 min)").ItemId: Simulation.Staircase 0:2 (10 min)
        'LeafElements("Square (10 s)").ItemId: Simulation.Square(10 s)
        'LeafElements("Register_ArrayOfBSTR").ItemId: Simulation.Register_ArrayOfBSTR
        'LeafElements("ReadValue_I2").ItemId: Simulation.ReadValue_I2
        'LeafElements("ReadValue_I1").ItemId: Simulation.ReadValue_I1
        'LeafElements("ReadValue_I4").ItemId: Simulation.ReadValue_I4
        'LeafElements("Ramp (1 s)").ItemId: Simulation.Ramp(1 s)
        'LeafElements("ReadValue_ArrayOfDATE").ItemId: Simulation.ReadValue_ArrayOfDATE
        'LeafElements("OnOff (1 s)").ItemId: Simulation.OnOff(1 s)
        'LeafElements("AlternatingQuality Uncertain (1 s)").ItemId: Simulation.AlternatingQuality Uncertain(1 s)
        'LeafElements("Register_NULL").ItemId: Simulation.Register_NULL
        'LeafElements("Random (1 min)").ItemId: Simulation.Random(1 min)
        'LeafElements("Random (10 min)").ItemId: Simulation.Random(10 min)
        'LeafElements("AlternatingError (10 s)").ItemId: Simulation.AlternatingError(10 s)
        'LeafElements("ReadValue_ArrayOfI1").ItemId: Simulation.ReadValue_ArrayOfI1
        'LeafElements("ReadValue_ArrayOfI2").ItemId: Simulation.ReadValue_ArrayOfI2
        'LeafElements("ReadValue_UI2").ItemId: Simulation.ReadValue_UI2
        'LeafElements("ReadValue_ArrayOfI4").ItemId: Simulation.ReadValue_ArrayOfI4
        'LeafElements("ReadValue_UI1").ItemId: Simulation.ReadValue_UI1
        'LeafElements("ReadValue_UI4").ItemId: Simulation.ReadValue_UI4
        'LeafElements("Weekdays (1 s)").ItemId: Simulation.Weekdays(1 s)
        'LeafElements("AlternatingQuality Uncertain (1 min)").ItemId: Simulation.AlternatingQuality Uncertain(1 min)
        'LeafElements("AlternatingQuality Uncertain (10 min)").ItemId: Simulation.AlternatingQuality Uncertain(10 min)
        'LeafElements("Weekdays (1 min)").ItemId: Simulation.Weekdays(1 min)
        'LeafElements("Weekdays (10 min)").ItemId: Simulation.Weekdays(10 min)
        'LeafElements("OnOff (10 s)").ItemId: Simulation.OnOff(10 s)
        'LeafElements("ReadWriteCount").ItemId: Simulation.ReadWriteCount
        'LeafElements("Register_UNKNOWN").ItemId: Simulation.Register_UNKNOWN
        'LeafElements("AlternatingQuality Uncertain (10 s)").ItemId: Simulation.AlternatingQuality Uncertain(10 s)
        'LeafElements("Constant_BSTR").ItemId: Simulation.Constant_BSTR
        'LeafElements("Constant_ERROR").ItemId: Simulation.Constant_ERROR
        'LeafElements("Constant_UI2").ItemId: Simulation.Constant_UI2
        'LeafElements("Constant_UI1").ItemId: Simulation.Constant_UI1
        'LeafElements("Constant_UI4").ItemId: Simulation.Constant_UI4
        'LeafElements("Constant_R4").ItemId: Simulation.Constant_R4
        'LeafElements("Constant_R8").ItemId: Simulation.Constant_R8
        'LeafElements("ReadValue_ArrayOfBSTR").ItemId: Simulation.ReadValue_ArrayOfBSTR
        'LeafElements("Register_ArrayOfR4").ItemId: Simulation.Register_ArrayOfR4
        'LeafElements("Register_ArrayOfR8").ItemId: Simulation.Register_ArrayOfR8
        'LeafElements("Ramp 0:360 (1 min)").ItemId: Simulation.Ramp 0:360 (1 min)
        'LeafElements("Ramp 0:360 (10 min)").ItemId: Simulation.Ramp 0:360 (10 min)
        'LeafElements("RegisterSet_n").ItemId: 
        'LeafElements("Register_ArrayOfUI4").ItemId Simulation.Register_ArrayOfUI4
        'LeafElements("Register_ArrayOfUI1").ItemId: Simulation.Register_ArrayOfUI1
        'LeafElements("Register_ArrayOfUI2").ItemId: Simulation.Register_ArrayOfUI2
        'LeafElements("Register").ItemId: Simulation.Register
        'LeafElements("Constant_EMPTY").ItemId: Simulation.Constant_EMPTY
        'LeafElements("Register_RECORD").ItemId: Simulation.Register_RECORD
        'LeafElements("ReadValue_ArrayOfBOOL").ItemId: Simulation.ReadValue_ArrayOfBOOL
        'LeafElements("AlternatingError (1 min)").ItemId: Simulation.AlternatingError(1 min)
        'LeafElements("AlternatingError (10 min)").ItemId: Simulation.AlternatingError(10 min)
        'LeafElements("OnOff (1 min)").ItemId: Simulation.OnOff(1 min)
        'LeafElements("ReadValue_DATE").ItemId: Simulation.ReadValue_DATE
        'LeafElements("Register_ERROR").ItemId: Simulation.Register_ERROR
        'LeafElements("ReadValue_ArrayOfUINT").ItemId: Simulation.ReadValue_ArrayOfUINT
        'LeafElements("Incrementing (10 s)").ItemId: Simulation.Incrementing(10 s)
        'LeafElements("ReadValue_ArrayOfINT").ItemId: Simulation.ReadValue_ArrayOfINT
        'LeafElements("ReadValue_BOOL").ItemId: Simulation.ReadValue_BOOL
        'LeafElements("Register_ArrayOfCY").ItemId: Simulation.Register_ArrayOfCY
        'LeafElements("Incrementing (1 s)").ItemId: Simulation.Incrementing(1 s)
        'LeafElements("Constant_UINT").ItemId: Simulation.Constant_UINT
        'LeafElements("ReadValue_ArrayOfR4").ItemId: Simulation.ReadValue_ArrayOfR4
        'LeafElements("ReadValue_ArrayOfR8").ItemId: Simulation.ReadValue_ArrayOfR8
        'LeafElements("Constant_I4").ItemId: Simulation.Constant_I4
        'LeafElements("Constant_I2").ItemId: Simulation.Constant_I2
        'LeafElements("Constant_I1").ItemId: Simulation.Constant_I1
        'LeafElements("Register_BOOL").ItemId: Simulation.Register_BOOL
        'LeafElements("Constant_UNKNOWN").ItemId: Simulation.Constant_UNKNOWN
        'LeafElements("Ramp 0:100 (1 s)").ItemId: Simulation.Ramp 0:100 (1 s)
        'LeafElements("Register_UI4").ItemId: Simulation.Register_UI4
        'LeafElements("Register_UI2").ItemId: Simulation.Register_UI2
        'LeafElements("Register_UI1").ItemId: Simulation.Register_UI1
        'LeafElements("AlternatingError (1 s)").ItemId: Simulation.AlternatingError(1 s)
        'LeafElements("Sine (10 s)").ItemId: Simulation.Sine(10 s)
        'LeafElements("Constant_BOOL").ItemId: Simulation.Constant_BOOL
        'LeafElements("Sine -100:100 (10 s)").ItemId: Simulation.Sine -100:100 (10 s)
        'LeafElements("Register_UINT").ItemId: Simulation.Register_UINT
        'LeafElements("Constant").ItemId: Simulation.Constant
        'LeafElements("Sine (1 s)").ItemId: Simulation.Sine(1 s)
        'LeafElements("Register_I1").ItemId: Simulation.Register_I1
        'LeafElements("Register_I2").ItemId: Simulation.Register_I2
        'LeafElements("Register_I4").ItemId: Simulation.Register_I4
        'LeafElements("ReadValue_ArrayOfCY").ItemId: Simulation.ReadValue_ArrayOfCY
        'LeafElements("Register_ArrayOfUINT").ItemId: Simulation.Register_ArrayOfUINT
        'LeafElements("Incrementing (1 min)").ItemId: Simulation.Incrementing(1 min)
        'LeafElements("Weekdays (10 s)").ItemId: Simulation.Weekdays(10 s)
        'LeafElements("Square (1 s)").ItemId: Simulation.Square(1 s)
        'LeafElements("Sine (1 min)").ItemId: Simulation.Sine(1 min)
        'LeafElements("Sine (10 min)").ItemId: Simulation.Sine(10 min)
        'LeafElements("Constant_DISPATCH").ItemId: Simulation.Constant_DISPATCH
        'LeafElements("Ramp 0:100 (1 min)").ItemId: Simulation.Ramp 0:100 (1 min)
        'LeafElements("Ramp 0:100 (10 min)").ItemId: Simulation.Ramp 0:100 (10 min)
        'LeafElements("Random (1 s)").ItemId: Simulation.Random(1 s)
        'LeafElements("Staircase 0:10 (1 min)").ItemId: Simulation.Staircase 0:10 (1 min)
        'LeafElements("Staircase 0:10 (10 min)").ItemId: Simulation.Staircase 0:10 (10 min)
        'LeafElements("AlternatingQuality Bad (1 s)").ItemId: Simulation.AlternatingQuality Bad(1 s)
        'LeafElements("Sine -100:100 (1 s)").ItemId: Simulation.Sine -100:100 (1 s)
        'LeafElements("Register_ArrayOfDATE").ItemId: Simulation.Register_ArrayOfDATE
        'LeafElements("AlternatingQuality Bad (10 s)").ItemId: Simulation.AlternatingQuality Bad(10 s)
        'LeafElements("ReadValue_R4").ItemId: Simulation.ReadValue_R4
        'LeafElements("ReadValue_R8").ItemId: Simulation.ReadValue_R8
        'LeafElements("Ramp (1 min)").ItemId: Simulation.Ramp(1 min)
        'LeafElements("Ramp (10 min)").ItemId: Simulation.Ramp(10 min)
        'LeafElements("Register_DISPATCH").ItemId: Simulation.Register_DISPATCH
        'LeafElements("OnOff (10 min)").ItemId: Simulation.OnOff(10 min)
        'LeafElements("ReadValue_BSTR").ItemId: Simulation.ReadValue_BSTR
        'LeafElements("Staircase 0:10 (10 s)").ItemId: Simulation.Staircase 0:10 (10 s)
        'LeafElements("Random (10 s)").ItemId: Simulation.Random(10 s)
        'LeafElements("Incrementing").ItemId: Simulation.Incrementing
        'LeafElements("Register_BSTR").ItemId: Simulation.Register_BSTR
        'LeafElements("ReadValue_UINT").ItemId: Simulation.ReadValue_UINT
        'LeafElements("Register_CY").ItemId: Simulation.Register_CY
        'LeafElements("AlternatingQuality Bad (1 min)").ItemId: Simulation.AlternatingQuality Bad(1 min)
        'LeafElements("AlternatingQuality Bad (10 min)").ItemId: Simulation.AlternatingQuality Bad(10 min)
        'LeafElements("Random").ItemId: Simulation.Random
        'LeafElements("Sine -100:100 (1 min)").ItemId: Simulation.Sine -100:100 (1 min)
        'LeafElements("Sine -100:100 (10 min)").ItemId: Simulation.Sine -100:100 (10 min)
        'LeafElements("Ramp (10 s)").ItemId: Simulation.Ramp(10 s)
        'LeafElements("ReadValue_INT").ItemId: Simulation.ReadValue_INT
        'LeafElements("Staircase 0:2 (1 s)").ItemId: Simulation.Staircase 0:2 (1 s)
        'LeafElements("ReadValue_CY").ItemId: Simulation.ReadValue_CY
        'LeafElements("Register_R8").ItemId: Simulation.Register_R8
        'LeafElements("Register_R4").ItemId: Simulation.Register_R4
        'LeafElements("Register_DECIMAL").ItemId: Simulation.Register_DECIMAL
        'LeafElements("Incrementing (10 min)").ItemId: Simulation.Incrementing(10 min)
        'LeafElements("Register_EMPTY").ItemId: Simulation.Register_EMPTY
        'LeafElements("Constant_INT").ItemId: Simulation.Constant_INT
        'LeafElements("Register_INT").ItemId: Simulation.Register_INT
        'LeafElements("Register_ArrayOfBOOL").ItemId: Simulation.Register_ArrayOfBOOL
        'LeafElements("Ramp 0:100 (10 s)").ItemId: Simulation.Ramp 0:100 (10 s)
        'LeafElements("Ramp 0:360 (10 s)").ItemId: Simulation.Ramp 0:360 (10 s)
        'LeafElements("Square (1 min)").ItemId: Simulation.Square(1 min)
        'LeafElements("Square (10 min)").ItemId: Simulation.Square(10 min)
        'LeafElements("Constant_DECIMAL").ItemId: Simulation.Constant_DECIMAL
        'LeafElements("Register_VARIANT").ItemId: Simulation.Register_VARIANT
        'LeafElements("Constant_DATE").ItemId: Simulation.Constant_DATE
        'LeafElements("Register_ArrayOfINT").ItemId: Simulation.Register_ArrayOfINT

    End Class
End Namespace

VBScript

Rem This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it displays 
Rem the ItemID of the node.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
On Error Resume Next
Dim LeafElements: Set LeafElements = Client.BrowseLeaves("", "OPCLabs.KitServer.2", "Simulation")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0

Dim LeafElement: For Each LeafElement In LeafElements
    WScript.Echo "LeafElements(""" & LeafElement.Name & """).ItemId: " & LeafElement.ItemId
Next

CSharp
Python
VB.NET

// This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it displays 
// the ItemID of the node.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

namespace DocExamples.DataAccess.Xml
{
    class BrowseLeaves
    {
        public static void Main1Xml()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();
            DANodeElementCollection leafElements;
            try
            {
                ServerDescriptor serverDescriptor = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx";
                leafElements = client.BrowseLeaves(serverDescriptor, "Static/Analog Types");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (DANodeElement leafElement in leafElements)
                Console.WriteLine($"LeafElements(\"{leafElement.Name}\").ItemId: {leafElement.ItemId}");
        }


        // Example output:
        //
        //LeafElements("Int").ItemId: Static/Analog Types/Int
        //LeafElements("Double").ItemId: Static/Analog Types/Double
        //LeafElements("Int[]").ItemId: Static/Analog Types/Int[]
        //LeafElements("Double[]").ItemId: Static/Analog Types/Double[]
    }
}

# This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it displays 
# the ItemID of the node.
#
# 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 .
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

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

# Instantiate the client object.
client = EasyDAClient()

try:
    leafElements = IEasyDAClientExtension.BrowseLeaves(client, ServerDescriptor('http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx'), DANodeDescriptor('Static/Analog Types'))
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message, sep='')
    exit()

for leafElement in leafElements:
    print('LeafElements("', leafElement.Name, '").ItemId: ', leafElement.ItemId, sep='')

# Example output:
#
#LeafElements("Int").ItemId: Static/Analog Types/Int
#LeafElements("Double").ItemId: Static/Analog Types/Double
#LeafElements("Int[]").ItemId: Static/Analog Types/Int[]
#LeafElements("Double[]").ItemId: Static/Analog Types/Double[]

' This example shows how to obtain all leaves under the "Simulation" branch of the address space. For each leaf, it displays 
' the ItemID of the node.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Imports OpcLabs.EasyOpc
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.AddressSpace
Imports OpcLabs.EasyOpc.OperationModel

Namespace DataAccess.Xml
    Partial Friend Class BrowseLeaves
        Shared Sub Main1Xml()
            Dim client = New EasyDAClient()

            Dim leafElements As DANodeElementCollection
            Try
                Dim serverDescriptor As ServerDescriptor = "http://opcxml.demo-this.com/XmlDaSampleServer/Service.asmx"
                leafElements = client.BrowseLeaves(serverDescriptor, "Static/Analog Types")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            For Each leafElement In leafElements
                Console.WriteLine($"LeafElements(""{leafElement.Name}"").ItemId: {leafElement.ItemId}")
            Next leafElement

        End Sub

        ' Example output
        '
        'LeafElements("Int").ItemId: Static/Analog Types/Int
        'LeafElements("Double").ItemId: Static/Analog Types/Double
        'LeafElements("Int[]").ItemId: Static/Analog Types/Int[]
        'LeafElements("Double[]").ItemId: Static/Analog Types/Double[]

    End Class
End Namespace

Requirements

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

Reference

IEasyDAClientExtension Class
IEasyDAClientExtension Members
Overload List

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