FindDirectory(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) Method

Finds a directory object under the specified parent directory.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<CanBeNullAttribute()>
Public Overloads Shared Function FindDirectory( _
   ByVal fileTransfer As IEasyUAFileTransfer, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal namedNodePath As UANamedNodePath _
) As UANodeDescriptor

'Usage
 
Dim fileTransfer As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim namedNodePath As UANamedNodePath
Dim value As UANodeDescriptor
 
value = IEasyUAFileTransferExtension.FindDirectory(fileTransfer, endpointDescriptor, namedNodePath)

[Extension()]
[CanBeNull()]
public static UANodeDescriptor FindDirectory( 
   IEasyUAFileTransfer fileTransfer,
   UAEndpointDescriptor endpointDescriptor,
   UANamedNodePath namedNodePath
)

[Extension()]
[CanBeNull()]
public:
static UANodeDescriptor^ FindDirectory( 
   IEasyUAFileTransfer^ fileTransfer,
   UAEndpointDescriptor^ endpointDescriptor,
   UANamedNodePath^ namedNodePath
)

Parameters

fileTransfer: The OPC UA file transfer object that will perform the operation.
endpointDescriptor: Endpoint descriptor. Identifies the OPC-UA server.
namedNodePath: The named node path to test.

Return Value

Returns a node descriptor of the directory object, if the directory was found. Returns null otherwise.

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.UA.OperationModel.UAException	The OPC UA 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.UA.OperationModel.UAException

The OPC UA 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.

Remarks

The OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.BaseNodeDescriptor of the namedNodePath must be an existing node in the server, of object type OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAObjectTypeIds.FileDirectoryType.

If the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.BaseNodeDescriptor of the namedNodePath does not denote an existing node of the OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAObjectTypeIds.FileDirectoryType object type, the method throws OpcLabs.EasyOpc.UA.OperationModel.UAException. If, however, the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.BaseNodeDescriptor of the namedNodePath denotes an existing directory node, but any of the child directories in the OpcLabs.EasyOpc.UA.Navigation.UANamedNodePath.PathElements of the namedNodePath does not exist, the method returns null.

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

IEasyUAFileTransferExtension Class
IEasyUAFileTransferExtension Members
Overload List
FindFile(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodeDescriptor) Method
FindFileOrDirectory(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodeDescriptor) Method
GetDirectory(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) Method
FindDirectory Method
IsDirectory(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) Method

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