'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Shared Function GetFileProvider2( _
   ByVal fileTransfer As IEasyUAFileTransfer, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal directoryNodeDescriptor As UANodeDescriptor _
) As IFileProvider2

'Usage
 
Dim fileTransfer As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim directoryNodeDescriptor As UANodeDescriptor
Dim value As IFileProvider2
 
value = IEasyUAFileTransferExtension.GetFileProvider2(fileTransfer, endpointDescriptor, directoryNodeDescriptor)

[Extension()]
[NotNull()]
public static IFileProvider2 GetFileProvider2( 
   IEasyUAFileTransfer fileTransfer,
   UAEndpointDescriptor endpointDescriptor,
   UANodeDescriptor directoryNodeDescriptor
)

[Extension()]
[NotNull()]
public:
static IFileProvider2^ GetFileProvider2( 
   IEasyUAFileTransfer^ fileTransfer,
   UAEndpointDescriptor^ endpointDescriptor,
   UANodeDescriptor^ directoryNodeDescriptor
) 

Parameters

fileTransfer

The OPC UA file transfer object that will perform the operation.

This is typically the EasyUAFileTransferClient object.

The value of this parameter cannot be null (Nothing in Visual Basic).

endpointDescriptor

Endpoint descriptor. Identifies the OPC-UA server.

Because the OpcLabs.EasyOpc.UA.UAEndpointDescriptor has implicit conversions from System.String and System.Uri, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the endpoint URL, or a so-called OPC UA endpoint descriptor string), or a System.Uri object, in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromString or OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromUri static method instead.

Also, because the OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement and OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement have an implicit conversion to OpcLabs.EasyOpc.UA.UAEndpointDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement (results from OPC UA discovery) in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can convert a (non-null) OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement to OpcLabs.EasyOpc.UA.UAEndpointDescriptor using the ToUAEndpointDescriptor or ToUAEndpointDescriptor method instead.

If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.EasyUAServerCore can be used in the same way to simply pass the server object in place of this parameter, which will use its OpcLabs.EasyOpc.UA.EasyUAServerCore.EffectiveServerDescriptor property for the connection.

The value of this parameter cannot be null (Nothing in Visual Basic).

directoryNodeDescriptor

Node descriptor of the OPC UA directory.

Because the OpcLabs.EasyOpc.UA.UANodeDescriptor has implicit conversions from OpcLabs.EasyOpc.UA.AddressSpace.UANodeId, OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement, OpcLabs.EasyOpc.UA.Navigation.UABrowsePath and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.AddressSpace.UANodeId object (representing the Id of the OPC UA node), a node element object (from OPC UA browsing), OpcLabs.EasyOpc.UA.Navigation.UABrowsePath object (representing OPC UA absolute browse path), or a string (with expanded node Id text) in place of this parameter, and the corresponding node descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.UANodeDescriptor.FromString, OpcLabs.EasyOpc.UA.UANodeDescriptor.FromUABrowsePath, OpcLabs.EasyOpc.UA.UANodeDescriptor.FromUANodeElement or OpcLabs.EasyOpc.UA.UANodeDescriptor.FromUANodeId static method instead.

If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode can be used in the same way to simply pass the server node in place of this parameter, which will use its OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode.EffectiveNodeDescriptor property for the operation.

The value of this parameter cannot be null (Nothing in Visual Basic).

Return Value

This method does not make any OPC UA operation, and does not throw the usual OpcLabs.EasyOpc.UA.OperationModel.UAException. You can therefore always safely use it to obtain the result interface. All OPC UA operations are made later, on the returned object, and also operation-related exceptions are thrown at that time.

A file provider is an abstraction of a file system, with access to its files and directories. Concrete implementations include a file provider for the physical file system (provided by the operating system), file providers for embedded resources, and, as in this case, a file provider for OPC UA File Transfer facility.

The returned file provider object allows only read-only operations on the file system - such as obtaining a read-only file info or directory contents, or setting up change notifications for the changes in the file system. If you need operations that modify the file system or data in its files, you need to obtain the OpcLabs.BaseLib.Extensions.FileProviders.IWritableFileProvider interface instead, by calling the GetWritableFileProvider method.

Accessing OPC UA files and directories over the abstract file provider model (based on Microsoft.Extensions.FileProviders.IFileProvider, Microsoft.Extensions.FileProviders.IFileInfo, OpcLabs.BaseLib.Extensions.FileProviders.IDirectoryContents2 and their "writable" counterparts), which is what this method does, is highly recommended over the other, lower-level methods. Once you obtained the generalized interface in the file provider model, operations on files and directories can be performed using just names and paths, without having to deal with OPC UA nodes and references.

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

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