QuickOPC User's Guide and Reference
FindParentDirectory Method (IEasyUAFileTransfer)



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.FileTransfer Namespace > IEasyUAFileTransfer Interface : FindParentDirectory Method
Endpoint descriptor. Identifies the OPC-UA server.
The directory node descriptor of the file or directory for which the parent directory should be found.
Find a parent directory of a file or another directory.
Syntax
'Declaration
 
<CanBeNullAttribute()>
Function FindParentDirectory( _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal fileOrDirectoryNodeDescriptor As UANodeDescriptor _
) As UANodeDescriptor
'Usage
 
Dim instance As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim fileOrDirectoryNodeDescriptor As UANodeDescriptor
Dim value As UANodeDescriptor
 
value = instance.FindParentDirectory(endpointDescriptor, fileOrDirectoryNodeDescriptor)

Parameters

endpointDescriptor
Endpoint descriptor. Identifies the OPC-UA server.
fileOrDirectoryNodeDescriptor
The directory node descriptor of the file or directory for which the parent directory should be found.

Return Value

If the fileOrDirectoryNodeDescriptor is a child directory or a file under a parent, the method returns a node descriptor of the parent directory. Otherwise, this method returns null.
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 fileOrDirectoryNodeDescriptor must be an existing node in the server, of object type OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAObjectTypeIds.FileType or OpcLabs.EasyOpc.UA.AddressSpace.Standard.UAObjectTypeIds.FileDirectoryType.

The organization of directories and files under parent directories is described here: . Directories and 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