'Declaration
 
<ExtensionAttribute()>
Public Shared Function CreateOrOpenFile( _
   ByVal fileTransfer As IEasyUAFileTransfer, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal directoryNodeDescriptor As UANodeDescriptor, _
   ByVal fileName As String _
) As ValueTuple(Of UANodeDescriptor,UAFileHandle)

'Usage
 
Dim fileTransfer As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim directoryNodeDescriptor As UANodeDescriptor
Dim fileName As String
Dim value As ValueTuple(Of UANodeDescriptor,UAFileHandle)
 
value = IEasyUAFileTransferExtension.CreateOrOpenFile(fileTransfer, endpointDescriptor, directoryNodeDescriptor, fileName)

[Extension()]
public static ValueTuple<UANodeDescriptor,UAFileHandle> CreateOrOpenFile( 
   IEasyUAFileTransfer fileTransfer,
   UAEndpointDescriptor endpointDescriptor,
   UANodeDescriptor directoryNodeDescriptor,
   string fileName
)

[Extension()]
public:
static ValueTuple<UANodeDescriptor^,UAFileHandle^> CreateOrOpenFile( 
   IEasyUAFileTransfer^ fileTransfer,
   UAEndpointDescriptor^ endpointDescriptor,
   UANodeDescriptor^ directoryNodeDescriptor,
   String^ fileName
) 

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.

fileName

The name of the file to create or open.

Return Value

When a client opens a file, it gets a file handle that is valid while the session is open. You should use the CloseFile method to release the handle when they do not need access to the file anymore. Make sure you also explicitly call System.IDisposable.Dispose on the file handle returned from this method. The OPC UA file handle, until disposed of, causes the client to keep a session open on the server.

This method always opens the file both for reading and for writing.

"Clients can open the same file several times for read. A request to open for writing shall return Bad_NotWritable when the file is already opened. A request to open for reading shall return Bad_NotReadable when the file is already opened for writing."

Recommendation: Whenever possible, do not use this method directly, and use a higher-level abstraction instead. You can create System.IO.Stream objects for accessing the file data by using methods like OpcLabs.EasyOpc.UA.IO.Extensions.IEasyUAFileTransferExtension2.OpenOrCreateStream, or obtain them through a file provider (using GetFileProvider2 or GetWritableFileProvider).

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows