QuickOPC User's Guide and Reference
BrowseBranches(IEasyDAClient,ServerDescriptor,DANodeDescriptor,String) Method
Example 



OpcLabs.EasyOpcClassic Assembly > OpcLabs.EasyOpc.DataAccess Namespace > IEasyDAClientExtension Class > BrowseBranches Method : BrowseBranches(IEasyDAClient,ServerDescriptor,DANodeDescriptor,String) Method
The client object that will perform the operation.
The OPC server involved in the operation.
Descriptor for the parent branch to be browsed (can be the root).
A wildcard string to filter the returned element names (empty string for no filtering)
Browses the specified branch (or root) in OPC server's address space, and returns information about child branches found. Browse for child branches. Specify server descriptor, and element name filter.
Syntax
'Declaration
 

<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function BrowseBranches( _
   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.BrowseBranches(client, serverDescriptor, parentNodeDescriptor, elementNameFilter)
[Extension()]
[ElementsNotNull()]
[NotNull()]
public static DANodeElementCollection BrowseBranches( 
   IEasyDAClient client,
   ServerDescriptor serverDescriptor,
   DANodeDescriptor parentNodeDescriptor,
   string elementNameFilter
)
[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static DANodeElementCollection^ BrowseBranches( 
   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 branch found. The keys of the keyed collection are the names of the branches.
Exceptions
ExceptionDescription
OpcLabs.EasyOpc.OperationModel.OpcExceptionThrown when the OPC operation fails.
System.ArgumentNullExceptionA null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.
Example
// This example shows how to obtain all branches at the root of the address space. For each branch, it displays whether 
// it may have child nodes.

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

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

            foreach (DANodeElement branchElement in branchElements)
                Console.WriteLine($"BranchElements(\"{branchElement.Name}\").HasChildren: {branchElement.HasChildren}");
        }


        // Example output:
        //
        //BranchElements("$ServerControl").HasChildren: True
        //BranchElements("Boilers").HasChildren: True
        //BranchElements("Simulation").HasChildren: True
        //BranchElements("SimulateEvents").HasChildren: True
        //BranchElements("Trends").HasChildren: True
        //BranchElements("Demo").HasChildren: True
        //BranchElements("Greenhouse").HasChildren: True
    }
}
Rem This example shows how to obtain all branches at the root of the address space. For each branch, it displays whether 
Rem it may have child nodes.

Option Explicit

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

Dim BranchElement: For Each BranchElement In BranchElements
    WScript.Echo "BranchElements(""" & BranchElement.Name & """).HasChildren: " & BranchElement.HasChildren
Next
Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012, Windows Server 2016; .NET Core, .NET 5, .NET 6: Linux, macOS, Microsoft Windows

See Also

Reference

IEasyDAClientExtension Class
IEasyDAClientExtension Members
Overload List

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