OPC Studio User's Guide and Reference
BrowseTree(IEasyUAClient,UAEndpointDescriptor,UANodeDescriptor) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.Extensions Namespace > IEasyUAClientExtension2 Class > BrowseTree Method : BrowseTree(IEasyUAClient,UAEndpointDescriptor,UANodeDescriptor) Method
The client object that will perform the operation.
Endpoint descriptor. Identifies the OPC-UA server.
Starting node descriptor. Identifies the node in OPC server's address space.
Allows to traverse through OPC UA address space data nodes under the specified node.
Syntax
'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function BrowseTree( _
   ByVal client As IEasyUAClient, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal nodeDescriptor As UANodeDescriptor _
) As ITreeTraversable(Of UANodeTreePosition)
'Usage
 
Dim client As IEasyUAClient
Dim endpointDescriptor As UAEndpointDescriptor
Dim nodeDescriptor As UANodeDescriptor
Dim value As ITreeTraversable(Of UANodeTreePosition)
 
value = IEasyUAClientExtension2.BrowseTree(client, endpointDescriptor, nodeDescriptor)

Parameters

client
The client object that will perform the operation.
endpointDescriptor
Endpoint descriptor. Identifies the OPC-UA server.
nodeDescriptor
Starting node descriptor. Identifies the node in OPC server's address space.

Return Value

Returns an enumerator of tree positions that will traverse through all nodes specified.
Exceptions
ExceptionDescription

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.

Remarks

If you want to enumerate through a sequence of the tree nodes, convert the result to a sequence using the OpcLabs.BaseLib.Graphs.Extensions.ITreeTraversableExtension.ToEnumerable<T> method.

The method automatically prevents recursion into nodes that have already been traversed.

The root position in a tree will correspond to the specified starting node. The OpcLabs.EasyOpc.UA.Graphs.UANodeTreePosition object for the root is special one, in that from its OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement properties, only its NodeId is filled in.

You can obtain nodeDescriptor e.g. by calling one of the browsing methods on OpcLabs.EasyOpc.UA.EasyUAClientCore object.

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