OPC Studio User's Guide and Reference
ListFileNames Method (IEasyUAFileTransfer)



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.FileTransfer Namespace > IEasyUAFileTransfer Interface : ListFileNames Method
Endpoint descriptor. Identifies the OPC-UA server.
Node descriptor of the OPC UA directory.
Obtains names of files under the specified parent OPC UA directory.
Syntax
'Declaration
 
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Function ListFileNames( _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal directoryNodeDescriptor As UANodeDescriptor _
) As StringCollection
'Usage
 
Dim instance As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim directoryNodeDescriptor As UANodeDescriptor
Dim value As StringCollection
 
value = instance.ListFileNames(endpointDescriptor, directoryNodeDescriptor)

Parameters

endpointDescriptor
Endpoint descriptor. Identifies the OPC-UA server.
directoryNodeDescriptor
Node descriptor of the OPC UA directory.

Return Value

Returns a collection of names of files under the parent directory specified by the directoryNodeDescriptor.
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.

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.

This method lists OPC UA nodes of object type FileType, which is described here: . The organization of files under directories is described here: . Files are referenced from their parent directory using the OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAReferenceTypeIds.Organizes reference type.

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