ListFileAndDirectoryNames(IEasyUAFileTransfer,UAEndpointDescriptor,UANodeDescriptor) Method

Obtains names of files and directories under the specified OPC UA directory.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ListFileAndDirectoryNames( _
   ByVal fileTransfer As IEasyUAFileTransfer, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal directoryNodeDescriptor As UANodeDescriptor _
) As StringCollection

'Usage
 
Dim fileTransfer As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim directoryNodeDescriptor As UANodeDescriptor
Dim value As StringCollection
 
value = IEasyUAFileTransferExtension.ListFileAndDirectoryNames(fileTransfer, endpointDescriptor, directoryNodeDescriptor)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static StringCollection ListFileAndDirectoryNames( 
   IEasyUAFileTransfer fileTransfer,
   UAEndpointDescriptor endpointDescriptor,
   UANodeDescriptor directoryNodeDescriptor
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static StringCollection^ ListFileAndDirectoryNames( 
   IEasyUAFileTransfer^ fileTransfer,
   UAEndpointDescriptor^ endpointDescriptor,
   UANodeDescriptor^ directoryNodeDescriptor
)

Parameters

fileTransfer: The OPC UA file transfer object that will perform the operation.
endpointDescriptor: Endpoint descriptor. Identifies the OPC-UA server.
directoryNodeDescriptor: Node descriptor of the OPC UA directory.

Return Value

Returns a collection of names of the files and directories under the specified OPC UA directory.

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 directoryNodeDescriptor must be an existing node in the server, of object type OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAObjectTypeIds.FileDirectoryType.

Recommendation: Whenever possible, do not use this method directly, and use a higher-level abstraction instead. See e.g. the GetDirectoryContents2(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) method, which allows you to obtain an object that can be enumerated for files and directories underneath, in a way that is generic and not tied to OPC UA specifics.

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
ListDirectoryNames(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) Method
ListFileNames(IEasyUAFileTransfer,UAEndpointDescriptor,UANamedNodePath) Method

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