BrowseTree(IEasyDAClient,DABrowseArguments,Func<IEnumerable<DANodeElement>,IEnumerable<DANodeElement>>) Method

Allows to traverse through OPC DA address space nodes under the specified node, using given browse arguments, transforming the sequence of child node elements using a specified function.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function BrowseTree( _
   ByVal client As IEasyDAClient, _
   ByVal browseArguments As DABrowseArguments, _
   ByVal nodeElementsTransformer As Func(Of IEnumerable(Of DANodeElement),IEnumerable(Of DANodeElement)) _
) As ITreeTraversable(Of DANodeTreePosition)

'Usage
 
Dim client As IEasyDAClient
Dim browseArguments As DABrowseArguments
Dim nodeElementsTransformer As Func(Of IEnumerable(Of DANodeElement),IEnumerable(Of DANodeElement))
Dim value As ITreeTraversable(Of DANodeTreePosition)
 
value = IEasyDAClientExtension2.BrowseTree(client, browseArguments, nodeElementsTransformer)

[Extension()]
[NotNull()]
public static ITreeTraversable<DANodeTreePosition> BrowseTree( 
   IEasyDAClient client,
   DABrowseArguments browseArguments,
   Func<IEnumerable<DANodeElement>,IEnumerable<DANodeElement>> nodeElementsTransformer
)

[Extension()]
[NotNull()]
public:
static ITreeTraversable<DANodeTreePosition^>^ BrowseTree( 
   IEasyDAClient^ client,
   DABrowseArguments^ browseArguments,
   Func<IEnumerable<DANodeElement^>^,IEnumerable<DANodeElement^>^>^ nodeElementsTransformer
)

Parameters

client: The client object that will perform the operation.
browseArguments: Holds arguments needed to browse OPC DA server nodes.
nodeElementsTransformer: Transforms a sequence of child node elements before it is used for further browsing.

Return Value

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

Exceptions

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.

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.DataAccess.Graphs.DANodeTreePosition object for the root is special one, in that from its OpcLabs.EasyOpc.DataAccess.AddressSpace.DANodeElement properties, only its ItemId is filled in.

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

Reference

IEasyDAClientExtension2 Class
IEasyDAClientExtension2 Members
Overload List